Although COVID-19 vaccinations are starting to make a difference and travel is resuming is fair to say that we are still far from where we were in 2019 and it may take some time to get back there.
This means our diving travel destinations have been changing and there is much more local diving than before. Big countries like the US have a lot of diving and Caribbean destination on their doorstep those travellers have still quite a lot to choose in comparison to others.
For Europeans, in the geographical sense, there are options for short haul travel. Those do not compare to your macro trip to South East Asia or pelagic trips to South America or Maldives or similar, however you can get some pretty good shots.
In 2020 I had my first experience in Massa Lubrense and this year I was back there.
I wrote about it last year if you are looking for more details on the logistics so in this post I will focus on photography.
Getting back into RIB diving
After 1 year of forced stop from boat diving getting back into a RIB diving with 15 liters steel tanks was a bit of a shock, certainly better than shore diving but yet not exactly streamlines especially as I decided to get a semi-dry suit. Due to stock shortages in UK I was only able to fit into a Scubapro Nova Scotia 7.5mm that has a lot of buoyancy. The suit was definitely toasty but required a lot of weight to go down as it was brand new. Temperatures range from 26 degrees at the surface to 17 at depth in certain sites so after a chilling experience last year this time I was definitely ok.
I did 2 sets of 3 days diving clocking a total of 16 dives. The dives were all close to 60 minutes (time to get back on the RIB by procedure) and depth of 33 meters. I have to say I avoid decompression dives but really this destination does require you to dive deeper than what you expect in tropical destinations.
I had the new Panasonic GH5 Mark II that fits in the housing of the Mark I and two Sea and Sea YS-D2 strobes. I took only two lenses the Canon 8-15mm fisheye with metabones smart adapter and the new (for me) Panasonic 45mm 2.8 macro.
The visibility can be an issue on the Italian coast however you can mitigate the issue with good technique and photoshop. Interestingly water is always clearer at depth where of course you lack light so strobe power is important to get a good shot.
Banco di Santa Croce is the best spot to meet large grouper and has many sea fans and also macro life, eagle rays and other things to be found.
I find also very interesting the schooling fish even if this is usually not well behaved Barracuda who never spin around or a variety of sea bream
For me the most interesting wide angle though are the cave shots at Scoglio dell’Isca and Punta Campanella
Sunburst opportunities are abundant and due to the depth relatively easy scorpionfish or small sea fans are ideal.
The performance of the Canon 8-15mm on micro four thirds is just legendary!
Close Up and Macro
Afternoon dives at Puolo but also dives in Santa Croce or Mitigliano offer lots of close up opportunities.
It was the time of testing the Panasonic 45mm 2.8 on land I had the impression it gave better rendering of the Olympus 60mm and I definitely prefer it underwater.
It is not just macro a long lens gets interesting closeup of large groupers
Diving in Italy delivered again. I am seriously thinking a group trip would be worth it next year based on the itinerary I sketched last year.
Dates for 2022 would be 4-11 September outside of school holidays the diving is really calm as most Italian divers are back to work and the conditions are usually superb. If you are interested leave a comment and I will come back to you with costs and planned itinerary.
If you have a GH5 (Mark I, II or S) you are probably not just doing underwater video but also taking scenes on land. In fact perhaps you are reading this blog and you do not even use your camera underwater.
Either way you know by now that shooting video just with your camera handheld is not a terribly good idea and the tools required are different from photography where once you have a tripod a remote shutter and a bunch of filters are practically set.
Video requires quite a bit of hardware. I have gone through this process and even tried to adapt some of my underwater hardware but it was really bulky and at the end you are better off with proper gear so I use Smallrig.
Smallrig is a Chinese company that makes tons of various bits for your camera for a variety of situations. The first item you need is a cage and they have just released a new updated version for the GH5 cameras.
Clicking the image above will take you to Amazon UK where you can check details of the item.
The cage is the starting point and you can put your camera strap the weight of 190 grams does not add terribly to the camera and in any case if you have a GH5 you are used to carry some more weight. The cage lives permanently on my GH5 unless I put it in the underwater housing.
I am now going to go through a series of set up that I use with some other components as well but first some words of warning.
Smallrig suggests to use a Nato handle on the left hand side however this blocks the HDMI side port from opening. In addition the arri locating pins are too high and if you use a side handle in arri format it will hang and not be level with the cage.
I wrote Smallrig to tell them and they accepted the feedback the reality is that they do not test designs with camera they run 3D simulations and they do not go and open all the ports, plugs etc. So the only handles that actually work with this cage and do not impede any functionality are in this article.
Monopod/Tripod Rig for Wildlife shooting
The basic rig for monopod and handheld work (this means you hold the camera steady and you do not move) has a top handle and a side handle plus a small microphone and if required an LCD shade.
I have gone through a series of handles for this cage and I have settled for the following items:
We are looking at £180 for all this hardware this stuff is not cheap however I just can’t emphasize how more ergonomic and effective this is compared to holding the camera directly.
I have this rig used it for my deer film project.
There are situations where setting up a gimbal is too much and you want to take simple footage handheld just using the camera IBIS. This works very well with a standard zoom lens like the Panasonic DG Leica 12-60mm or the Lumix 12-60mm.
In those situations is better to have two handles and the set up needs to be as light as possible.
You will notice that the handles are smaller and they are also lighter. If you walk with your camera you are typically using the LCD and with two handles you are able to be much more steady if you were just gripping the camera.
You can also use the EVF instead of the LCD if you prefer to have three points of contact with the camera.
In those situation where you are in a studio or controlled environment you can use manual focus for pulling and usually you also have a monitor to have precise exposure. I tend to use this on a fluid video head and sturdy tripod for indoor shots.
Here I am shooting the mighty PanaLeica 10-25mm and I have my trusted Swit CM-55c field monitor.
I have an atomos ninja however since the GH5M2 has 60 fps in camera at 10 bits I only use it in bright outdoor scenes and the SWIT is just better in terms of tools and lighter.
With the new linear focus option for manual focus you can have a complete 360 degree turn of the wheel for manual focus if you so wish or shorter runs if preferred. I use 300 degrees.
It can be a bit daunting to search for the right items that do the job when you want to use your cage I hope this article will help you making the right choices and save time without having to do the trial error and return process I have done in the last year!
Disclaimer: there are many USB power banks on sale however most of them do not declare the maximum output current and therefore you cannot be sure that it will work in all situations I describe. The equipment I use does work and is proven by my daily experience, the suggestions are not prescriptive but if you choose your own parts you do do at your own risk
It has been some time since my post on chargers and recharge facilities. During the pandemic I have done a considerable amount of land based photography including wildlife, landscape and astrophotography so I have had the opportunity to develop the concept of portability further on the field. So I wanted to share my experience with you all as some of the findings are beneficial in every day situation.
Charging your camera battery
Today some cameras can charge the battery in camera using USB. In almost all cases the camera needs to be turned off to allow charging, as a complete recharge of your battery can take a few hours I never use this method. I always rely on spare batteries typically 3 and a dual battery charger that can be powered using USB. I use Newmova they are cheap and cheerful for both my Panasonic and Olympus cameras.
Newmowa Dual USB Charger for Olympus BLH-1 and OM-D EM1 Mark II, OM-D E-M1X Camera £9.99
Newmowa Dual USB Charger for Panasonic DMW-BLF19 and Panasonic DMC-GH3,DMC-GH4 DMC-GH5, DC-GH5S(DMW-BLF19 Dual USB Charger) £9.99
With 3 batteries you can have two in the charger if needed and one in the camera which means uninterrupted shooting for a long period of time depending on your use.
I also use battery grips in particular for my Olympus camera. Battery grip provide the most benefit when you are not wanting to interrupt shooting while swapping batteries. I usually set the camera to use the grip battery first and the camera as back up which means you can then insert another battery in the grip and keep shooting. I do not recommend using a battery grip as a sole source of power as at the end you can can go through 2 batteries relatively fast if you use quick burst shooting. The other dis-benefit of the grip is the one battery is always locked inside the camera so you need to increase your total battery stock to 4 if you use a dual charger. The grip is very useful to shoot verticals and provide weather sealing but overall is not my favourite option and I only use it for specific session on my Olympus camera because I only have 2 batteries.
There are some working 3rd party battery grip like this one that function AS LONG AS YOU USE ORIGINAL OEM BATTERIES.
Neewer Battery Grip Compatible with Panasonic Lumix G9 Camera Replacement for DMW-BGG9 with Shutter Release Focus Point Control Joystick £59.99
I have not seen versions for Olympus camera and the original battery grip is expensive. I got mine second hand for a good price.
Again if you only have two batteries or you want to rotate 4 batteries a battery grip is a good option if you don’t mind the extra weight.
I use a relatively simple USB power bank as I do not have PD capable cameras. This power bank has a decent capacity but more importantly it can output 4.5A using two outlets.
This power bank has also a light included very useful for your night photography. You can also use it to charge your phone but with two outlets means you can power two dual USB chargers and effectively charge 4 batteries twice until it runs out (typical battery less than 2000 mAh).
This power bank can also be used as constant power supply for cameras that take a dummy battery and do not support powering through USB.
DMW-DCC12 USB Power Cable kit DMW-DCC12 DC Coupler Dmw-Blf19 Dummy Battery (BLF-19 Battery Replacement) Compatible with PANASONIC DMC-GH3 DMC-GH4 DMC-GH3K DMC-GH4K DC-GH5 GH9 and more Digital Cameras £22.99
Using the power bank with this fake battery kit means I can run my GH5 in video for days (8.72x batteries equivalent charge).
IT IS VERY IMPORTANT THAT YOUR POWER BANK OUTPUTS MORE THAN 3A OTHERWISE IF YOU USE MECHANICAL SHUTTER THE CAMERA MAY GO IN SHUTTER VIBRATION AND SUFFER PERMANENT DAMAGE
Some well know power bank from respectable brands like anker and even rawpower themselves only outputs 3A current total so when the mechanical shutter is used and the camera draws more current you run into issue. This also happens when you set a custom white balance and the camera triggers the mechanical shutter. So if you have such power bank you are limited and hence I do not recommend them.
If you also use flash you can use the same chargers I already linked in the previous article
Prices have dropped to £7.99 for the micro USB and £9.99 for the dual USB C and micro USB input. Note that despite the misleading description the two chargers are identical except one has micro USB and the other also USB-C. The USB-C version is slightly bigger (70x90x23 mm USB version vs 97x114x34mm USB C). The USB C version has a stronger output for AAA batteries that I do not use and it does not charge faster standard AA so don’t be mislead.
Another useful accessory if you do astrophotography in humid or cold environment is a lens warmer. There are two versions I recommend the one with the temperature regulator as the strip gets to 50 C and this can increase dark current noise in your shots.
COOWOO Lens Heater Warmer Dew Heater with Temperature Regulator Strip for Ice Fog Universal Camera Telescopic Bottle Heating (Black)
Amazon.com links for my American followers
EBL 40Min Smart Fast USB Battery Charger for AA AAA Ni-MH Rechargeable Batteries
DMW-DCC12 USB Power Cable kit DMW-DCC12 DC Coupler Dmw-Blf19 Dummy Battery (BLF-19 Battery Replacement) Compatible with PANASONIC DMC-GH3 DMC-GH4 DMC-GH3K DMC-GH4K DC-GH5 GH9 and more Digital Cameras
Neewer Battery Grip for Panasonic G9
RavPower 16750 mAh 4.5A dual USB power bank
NewMowa Olympus dual charger
NewMowa Panasonic dual USB charger
COOWOO Lens Heater Warmer Dew Heater with Temperature Regulator Strip for Ice Fog Universal Camera Telescopic Bottle Heating (Black)
It is now almost one year since Covid-19 lockdown in UK and a bit more since my business travel has stopped. Next week I will getting my Covid-19 first vaccine jab but we do not yet have full clarity about the implications on leisure and business travel. The various countries are dealing with the pandemic with different degrees of speed and effectiveness and it is possible that some of the most exotic diving destinations will be on the allowed travel list later than western countries.
Many people have discovered local diving out of necessity and some have also done underwater photography in their bath, however for me this was not sufficient.
Since last year I formally joined a photography club and looked at expanding my interests. In 2020 as I have been staying at home I have taken the highest number of photos to date.
At beginning I thought: how can I reuse some of my camera lenses I use underwater on land? Mostly this was about macro in the garden. Slugs, bees and flowers were part of the first part of the journey.
I soon realised the skillset was similar but not identical and there were specific requirements to be fulfilled.
I then moved into abstract tried some portraits and more night photography. I needed to start investing in more lenses as I was getting more specialised and improving in the task.
I also started some bird photography in the garden using feeders to entice little birds. This proved challenging but I discovered I much more preferred predators and larger birds so I started going on walks locally to photography red kites. I already had a long lens so with a teleconverter started getting better at photographing birds in flight.
All of this has been done locally without the need to travel.
After a short summer break, where I got to do some diving re-discovering the beauty of Sorrento peninsula and the amazing diving on the coast, it was time to get back to England with the somewhat grim prospect of a very dire winter in full lockdown.
Woburn Abbey and deer park owned by the Duke of Bedford and spanning across the towns of Woburn and Ridgmont.
I went there the first time in November and literally fell in love with the location. After many early morning rise and many pictures taken I decided it was time for a video project.
Deer are sufficiently large that are not too difficult to film compared to birds and are extremely rewarding as they tend to stare at you.
The winter season has been an opportunity also for late sunrise which meant not so early wake up calls to get there for the golden hour.
Now that we are coming to the end of the full lockdown scheduled for March 29th I have decided to release a short film to remember what it was during this period and the magic moments I had the privilege to experience mostly on my own in the Woburn Deer Park.
The film will be released on my YouTube channel on Friday 26th of March at 8PM GMT. To make it easier to digest I will upload it in separate parts and if possible as a whole. YouTube is being very slow to process footage in the last months so I hope it will be all up next week.
I hope you will enjoy it. It is a total of 26 minutes of duration out of around 2 TB of video material collected in the months of January, February and March 2021. I will be putting posts on how it was shot in case you also want to expand your horizons…
The previous post on the technical nature of V-LOG has stirred up quite a bit of unset among those people that advocate the use of it as a preferred gamma for video capture. In this post I will show some data point to help you make an informed decision based on what you are planning to shoot in your video project.
Basics of Display Gamma and Dynamic Range
First of all a bit of background on gamma curves. The standard video gamma is based on a correction factor of 0.45 as screen decode it with the reciprocal value 2.22.
Cinema gamma is historically based on a value of 1/2.6 as projectors decode with a gamma of 2.6.
Today most of our content is consumed on phones, monitors or Tv screens as well as of course cinemas but for the purpose of this post I will assume we do not have a real ambition to project in cinemas.
To give some ideas of the dynamic range of the display consider those values
Tv (1886 HDTV)
Typical Display Dynamic Range
It is important to understand how the content we produce will be consumed when we capture our source material as otherwise our video pipeline may be suboptimal.
Mobile phones and tablets are now the predominant platform to consume content and looking at the table above this means that in terms of dynamic range there is not a high requirement. In addition phones and computer monitors may also not be particularly accurate in terms of colour rendition.
HDR content, due to lack of widespread compatibility, is growing on mobile phones but remains a product for high end platforms such as HDR TVs and Projectors.
It follows that content that will be displayed at the best quality on the most common platforms has pretty limited requirements in terms of dynamic range and other qualities are perhaps more important such as sharpness, low amount of noise, colour rendition and delivery of what looks high contrast on a limited contrast medium.
A further obvious consideration is that standard rec709/sRGB video is limited to 10 stops of dynamic range in the display (contrast ratio 1000:1) while new TV sets aligned to BT.1886 can display 11 stops )(Contrast ratio 2000:1). So no matter how you acquire if you end up in rec709 the dynamic range is limited and it becomes more important to accurately capture tones and colors.
Gamma Curves for Capture
As explained capture gamma is the reciprocal of display gamma and therefore majority of cameras capture a standard video gamma (0.45) or in some cases an HDR gamma (logarithmic). I do not want this post to become a deep dive on HDR video of which I have written enough however to stay on course I want to compare traditional gamma (non linear) and log gamma.
In the following graph you see the bit codes output vs input of a standard video gamma (1/2.2) a cine gamma (1/2.6) and a log gamma (v-log).
In broad terms you can see that a video gamma produces an output of 3865 vs 16383 bits, a cinema gamma sets at 3166, while a Log gamma can take all 14 bits of data and still be within bit value 960.
It follows that to store the whole set of values read at 14 bits into a 10 bits container a standard gamma needs to do some scaling while a log gamma does not need scaling to fit into a 10 bits container. This also explains why exposure values in log are 2 stops higher than standard video for a 14 bit range, while for a 12 bit range the offset is one stop. As the meter is using a standard RGB gamma all values are rescaled back.
You notice that at no point here I have made references to dynamic range. The camera dynamic range is solely related to the maximum well capacity vs the read noise and it does not relate to the gamma curve being used, however the different compression of the gamma curve have an effect on how tones are mapped and on the perceived dynamic range.
Camera Dynamic Range vs Display Dynamic Range
The overall camera dynamic range influences what you can do with your content and if it is worthwhile to produce an HDR version or not.
If we compare the previous table of display dynamic range vs camera dynamic range and we focus on nominal values (SNR=1) and photographic (SNR=20) we can see what device we need for our purpose.
Dynamic Range by Sensor Type
We can see that if all we need to do is to output on a mobile device or a computer monitor smaller sensor are adequate, however for HDR production larger format are preferred. Obviously we can stretch SNR to lower values and this will upgrade the above table of 1 stops or so but not change our reasoning substantially.
Gamma curves vs Bit codes mapping
The various gamma curves have a different distribution of tones (bit values), in this table I compare a video gamma vs cinema a reduced 12 stops log and a full Vlog for a full frame sensor camera.
For the purpose of this comparison blacks are bit codes in the lowest 10%, Shadows are up to 18%, midtones up to 75%, highlights up to 90% and whites above. Blacks and whites do not have color information but just brightness while shadows, midtones and highlights contain respectively dark, medium and light hues.
A standard video gamma has over 45% of midtones, those are the colors and tones with intermediate values so produce softer tones. Shadows are just above 35% with highlights under 10% and blacks and whites around 5%.
If we look at a cinema gamma we can see that shadows are now predominant and very close to the midtones, highlights, whites and blacks are compressed.
V-LogL (12 stops DR 12 bit implementation) has the largest range in shadows, midtones are compressed around 50% compared to a video gamma, blacks are subtantially more than a video gamma, and while highlights are compressed, whites are super whites are greatly expanded.
Full VLog is dominated by whites that make 38% of the bit values, Shadows are at 32% with midtones now under 20% and highlights compressed. Blacks remain expanded.
Choosing a Gamma Curve for your Video Project
Our decision tree starts from the content which determines the device we need. Once we have a device capable of a given dynamic range we can make appropriate choices in terms of gamma curve.
Broadly speaking compact cameras and micro four thirds do not have enough device dynamic range at sufficient level of SNR to justify a high dynamic range gamma. There are some very specific exception where this may be worth it (Panasonic GH5s) but in general terms a standard MFT camera for photography should be limited to video or cinema gamma for optimal results as the dynamic range is limited and compression is not required.
If you own an MFT camera your choice is between a video gamma and a cinema gamma. Depending on the look you want to achieve you may choose one or the other. Video gamma has generally more contrast (more blacks and highlights and whites) while Cine gamma has a balance between midtones and shadows but not strong blacks and whites giving overall a softer look.
If you own a full frame or apsc camera you have more options which means you need to think more about the gamma curve to be used. HDR content requires a log curve you can then decide to use a cinema or video gamma if you do not want to output HDR or want to achieve a different look. It is important to note that log gamma have lots of bit values in whites and super whites and those do not exist in many typical scenes.
Scene vs Dynamic Range
While the current effort of camera manufacturers is to promote high dynamic range the reality is that in most cinematography situation you use devices that reduce contrast and therefore dynamic range (think about pro mist filters).
The DR of a scene can be evaluated looking at the histogram. This is of course influenced by the gamma curve so it is important to do this evaluation taking a photograph not video.
The following are example of scenes with the underlying histogram.
It may be useful to see the effect of LOG using the LUTs in photoshop on the raw data
The example above shows that a significant number of midtones have been lost in the conversion with no DR benefit as the scene essentially lacked it.
For underwater video purposes as the water reduces contrast and smooths highlights I would not recommend shooting log or HDR with the exception of very specific scenarios. Likewise if I am shooting a v(ideo)log or an interview there is no requirement for extra dynamic range and log compression is not required.
Outdoor scenes especially in bright conditions, snow, are appropriate for HDR and should be shot with a log format assuming of course the luminance of the scene is not being reduced with ND filters or similar.
Events like weddings can have challenging conditions with a mix of low contrast indoor and bright outdoors with the bride typically dressed in white so in effect those can be very demanding on the equipment but you need to bear in mind that if your delivery format is just HD video the benefit of log gamma are greatly reduced and extensive work may be required to bring colours back in check, always account for the limitations of your equipment as well.
There is no doubt that LOG formats in digital cameras have a halo of mystery around them mostly due to the lack of technical documentation on how they really work. In this short article I will explain how the Panasonic V-Log actually works on different cameras. Some of what you will read may be a surprise to you so I have provided the testing methods and the evidence so you can understand if LOG is something worth considering for you or not. I will aim at making this write up self-contained so you have all the information you need here without having to go and search elsewhere, it is not entirely possible to create a layman version of what is after all a technical subject.
A logarithmic operator is a non-linear function that processes the input signal and maps it to a different output value according to a formula. This is well documented in Panasonic V-Log/V-Gamut technical specifications. If you consider the input reflection (in) you can see how the output is related to the input using two formulas:
IRE = 5.6*in+0.125 (in < cut1 ) *
IRE = c*log10(in+b)+d (in >= cut1 )
Where cut1 = 0.01, b=0.00873, c=0.241514, d=0.598206
There are few implications of this formula that are important:
0 input reflectance is mapped to 7.3% IRE
Dark values are not compressed until IRE=18%
Middle Grey (18% reflectance) is still 42% IRE as standard Rec709
White (90% reflectance) is 61% IRE so much lower than Rec709
100% IRE needs input reflectance 4609 which is 5.5 stops headroom for overexposure.
So what we have here is a shift of the black level from 0% to 7.3% and a compression of all tones over 18% this gives the washout look to V-LOG that is mistakenly interpreted as flat but it is not flat at all. In fact the master pedestal as it is known in video or black level is shifted. Another consequence of this formula is that VLOG under 18% IRE works exactly like standard gamma corrected Rec709 so it should have exactly the same performance in the darks with a range between 7.3% and 18% instead of 0-18%.
In terms of ISO measured at 18% reflectante V-LOG should have identical ISO value to any other photo style in your camera this means at given aperture and exposure time the ISO in a standard mode must match V-LOG.
When we look at the reality of V-LOG we can see that Panasonic sets 0 at a value of 50% IRE so generally ⅔ to 1 full stop overexposed this becomes obvious when you look at the waveform. As a result blacks are actually at 10% IRE and whites at 80% once a conversion LUT is applied.
Challenges of Log implementation
LOG conversion is an excellent method to compress a high dynamic range into a smaller bit depth format. The claim is that you can pack the full sensor dynamic range into 10 bits video. Panasonic made this claim for the GH5s and for the S1H, S5.
There is however a fundamental issue. In a consumer digital camera the sensor is already equipped with a digital to analog converter on board and this operates in a linear non log mode. This means the sensor dynamic range is limited to the bit depth of the analog to digital converter and in most cases sensors do not even saturate the on board ADC. It is true that ADC can also resolve portions of bits however this does not largely change the picture.
If we look at the sensor used in the S1H, S5 this is based on a Sony IMX410 that has saturation value of 15105 bits or 13.88 stops of dynamic range. The sensor of the GH5s which is a variant of Sony IMX299 has a saturation of 3895 (at 12 bits) or 11.93 stops.
None of the S1H, S5 or GH5s actually reaches the nominal dynamic range that the ADC can provide at sensor level. The sensor used by the GH5 has more than 12 stops dynamic range and achieves 12.3 EV of engineering DR, as the camera has 12 bits ADC it will resolve an inferior number of tones.
So the starting point is 12 or 14 stops of data to be digitally and not analogically compressed into 10 bits coding. Rec709 has a contrast ratio requirement of 1000:1 which is less than 10 stops dynamic range. This has not to be confused with bit depth. With 8 bits depth you can manage 10 stops using gamma compression. If you finish your work in Rec709 the dynamic range will never exceed log2(1000)=9.97 stops. So when you read that rec709 only has 6.5 stops of DR or similar it is flawed as gamma compression squeezes the dynamic range into a smaller bit depth.
When we look at a sensor with almost 14 stops of dynamic range the standard rec709 gamma compression is insufficient to preserve the full dynamic range as it is by default limited to 10 stops. It follows that logically LOG is better suited to larger sensors and this is where it is widely used by all cinema camera manufacturers.
In practical terms the actual photographic dynamic range (this is defined as the dynamic range you would see on a print of 10″ on the long side at arm length), the one you can see with your eyes in an image, is less than the engineering value. The Panasonic S5 in recent tests showed around 11.5 stops while the GH5S is around 10 and the GH5 9.5 stops of dynamic range. Clearly when you look at a step chart the tool will show more than this value but practically you will not see more DR in real terms.
This means that it is possible that a standard gamma encoded video in 10 bits can be adequate in most situations and nothing more is required. There is also a further issue with noise that the log compression and decompression produces. As any conversion that is not lossless the amount of noise increases: this is especially apparent in the shadows. In a recent test performed with a S5 in low light and measured using neat-video assessment V-Log was one of the worst performed in terms of SNR. The test involved shooting a color checker at 67 lux of ambient illumination and reading noise level on the 4 shadows and darks chips. Though this test was carried out at default setting it has to be noted that even increasing the noise reduction in V-LOG does not eliminate the noise in the shadow as this depends on how V-LOG is implemented.
The actual V-Log implementation
How does V-LOG really work? From my analysis I have found that V-Log is not implemented equally across cameras, this is for sure a dependency on the sensor performance and construction. I do not know how a Varicam camera is built but in order to perform the V-Log as described in the document you need a log converter before the signal is converted to digital. In a digital camera the sensor already has an on board ADC (analog to digital converter) and therefore the output is always linear on a bit scale of 12 or 14 bits. This is a fundamental difference and means that the math as illustrated by Panasonic in the V-LOG/V-Gamut documentation cannot actually be implemented in a consumer digital camera that does not have a separate analog log compressor.
I have taken a test shot in V-LOG as well as other standard Photo Styles with my Lumix S5 those are the RAW previews. V-LOG is exactly 2 2/3 stops underexposed on a linear scale all other parameters are identical.
What is happening here? As we have seen ISO values have to be the same between photo styles and refer to 18% middle grey however if you apply a log conversion to a digital signal this results in a very bright image. I do some wide field astrophotography and I use a tool called Siril to extract information from very dark images this helps visualise the effect of a log compression.
The first screenshot is the RAW file as recorded a very dark black and white image as those tools process separately RGB.
The second image shows the same RAW image with a logarithmic operator applied; this gives a very bright image.
Now if you have to keep the same middle grey value exposure has to match that linear image so what Panasonic does is to change the mapping of ISO to gain. Gain is the amplification on the sensor chip and has values typically up to 24-30 dB or 8 to 10 stops. While in a linear image the ISO would be defined as 100 at zero gain (I am simplifying here as actually even at 100 there will be some gain) in a log image zero gain corresponds to a different ISO value. So the mapping of ISO to gain is changed. When you read that the native ISO is 100 in normal mode and 640 in V-LOG this means that for the same gain of 0 dB a standard image looks like ISO 100 and a V-LOG image looks like ISO 640, this is because V-LOG needs less gain to achieve the same exposure as the log operator brightens the image. In practical terms the raw linear data of V-LOG at 640 is identical to an image taken at 100.
This is the reason why when a videographer takes occasional raw photos and leaves the camera in V-LOG the images are underexposed.
The benefit of the LOG implementation is that thanks to log data compression you can store the complete sensor information in a lower bit depth in our case this means going from 14 to 10 bits.
There are however some drawbacks due to the fact that at linear level the image was ‘underexposed‘, I put the terms in italic as exposure only depends on time and aperture of the lens, so in effect is lack of gain for which there is no term.
The first issue is noise in the shadows as those on a linear scale are compacted, as the image is underexposed: a higher amount of noise is present and this is then amplified by the LOG conversion. It is not the case that LOG does not have noise reduction, in fact standard noise reduction expects a linear signal gamma corrected and therefore could not work properly (try setting a high value in V-LOG on a S camera to see the results), the issue is with the underexposure (lack of gain) of the linear signal.
There are also additional side effects due to what is called black level range, I recommend reading on photonstophotos a great website maintained by Bill Claff. When you look at black levels you see that cameras do not really have pure black but have a range. This range results in errors at the lower scale of the exposure; the visible effect is colour bleeding (typically blue) in the shadows when there is underexposure. As V-LOG underexposed in linear terms you will have issues of colour bleeding in the shadows: those have been experienced by several users so far with no explanation.
The other side effect is that the LUT to decompress V-LOG remains in a 10 bit color space which was insufficient to store the complete dynamic range data and this does not change. So the LUT does not fully reverse the log compression in Panasonic case this goes into the V709 CineLike Gamma which is in a Rec709 gamma. As the full signal is not decompressed means that there are likely errors of hue accuracy so V-LOG does not have a better ability to reproduce accurate colors and luminance and this is the reason why even after a LUT is applied it needs to be graded. If you instead decompress V-LOG in a log space like Rec2020 HDR you will see that it does not look washed out at all and colors are much more vibrant as the receiving space has in excess of 20 stops.
Some users overexpose their footage saying they are doing ETTR. Due to the way log is implemented this means it will reach a clipping point sooner and therefore the dynamic range is no longer preserved. This is a possible remedy to reduce the amount of noise in low light however the log compression is not fully reversed by the LUT that is expecting middle grey exposure and therefore color and luminance accuracy errors are guaranteed. If you find yourself regularly overexposing V-LOG you should consider not using it at all.
Shadow Improvement and input referred noise
The Lumix cameras with dula gain sensor have a different behaviour to those without. This is visible in the following two graphs again from Bill Claff excellent website.
The first is the shadow improvement by ISO here you can see that while the GH5/G9 stay flat and are essentially ISO invariant, the GH5S and S5 that have a dual gain circuit have an improvement step when they go from low to high gain. What changes here is due to the way the sensors of the GH5s and S5 are constructed, the back illumination means that when the high gain circuit is active there is a material improvement in the shadows and the camera may even have a lower read noise at this ISO (gain) point than it had before because of this.
Another benefit of dual gain implementation is easier to understand when you look at input referred noise graphs. You can see that as the sensor enters the dual gain zone the input referred noise drops. Input referred noise means the noise that you would need to feed as an input to your circuit to produce the same noise as output. So this means when that step is passed the image will look less noisy. Again you can see that while the GH5 stays relatively flat the GH5s and S5 have a step improvement. Is it is not totally clear what happens in the intermediate zone for the GH5s possibly intermediate digital gain or more noise reduction is applied.
The combination of a certain type of sensor construction and dual conversion gain can be quite useful to improve shadows performance.
Do not confuse dual gain benefit with DR preservation, while dual gain reduces read noise it does not change the fact that the highlights will clip as gain is raised. So the effective PDR reduces in any case and is not preserved. The engineering DR is preserved but that is only useful to a machine and not to our eyes.
Now we are going to look at specific implementation of V-LOG in various camera models.
Front Illuminated 12 bits Sensors
Those are traditional digital cameras for photos and include the GH5, G9 for example. On those cameras you will see that the V-Log exposure shows a higher ISO value of 1 stop compared to other photo styles at identical aperture and shutter speed setting but the actual result is the same in a raw file so your RAW at 400 in VLOG is the same of another photo style at 200. This is a direct contradiction of Panasonic own V-Log model as the meter should read the same in all photo styles so something is going on here. As there is no underexposure it follows that there is no real log compression either. Those cameras are designed in a traditional way so low ISO (gain) is good high ISO (gain) is not. This is visible in the previous graphs.
Those screenshot show how the raw data of an image taken at ISO 250 in standard mode is identical to the V-LOG image and therefore shows how there is not LOG compression at all in the GH5. V-LOGL of the GH5 is therefore just a look and does not have any increase of dynamic range compared to other photo styles.
Is this version of V-LOGL more effective than other photo style with a compressed gamma like CineLikeD? According to Panasonic data CineLikeD has 450% headroom so it is already capable of storing the whole dynamic range that the GH5 can produce (450% means 12.13 stops vs 12.3 theoretical maximum).
In addition noise performance of V-Log is worse because all is doing is acting on shadows and highlights and not really doing any log conversion. The business case for acquiring a V-Log key on those cameras is limited if the objective was to preserve dynamic range as the camera already has this ability with photo styles included with the camera and moreover the V-LOG is not actually anything related to LOG compression otherwise the image would have needed to have less gain and would have shown underexposed. The fact that the camera is shooting at nominal ISO 400 means most likely that some form of noise reduction is active to counter the issue that V-Log itself introduces of noise in the shadows. So in this type of camera V-LOG is only a look and does not accomplish any dynamic range compression.
Back Illuminated 12 bits readout sensors
The cameras that have this technology are the GH5s and the BGH1, the back illumination gives the sensor a better ability to convert light into signal when illumination levels are low. Those cameras have actually a sensor with an 14 bits ADC but this is not used for video.
In order to decompose the procedure I have asked a friend to provide some RAW and Jpeg images in Vlog and normal. You can see that in the GH5s there is 1 stop underexposure and therefore a light form of log compression.
In the GH5s implementation the camera meters zero at the same aperture shutter and ISO in LOG and other photo styles and zero is 50% IRE so actually is 1 stop overexposed.
The procedure for V-Log in this cameras is as follows:
Meter the scene on middle grey + 1 stop (50%)
Reduce gain of the image 1 stop behind the scenes (so your 800 is 400 and 5000 is 2500)
Digital log compression and manipulation
As the underexposure is mild this means the log compression is also mild as it is only recovering 1 stop as the two effect cancels this is actually a balanced setting.
The IMX299 dual gain implementation was a bit messed up in the GH5s but has been corrected in the BGH1 with the values of 160 and 800. It is unclear what is happening to the GH5s and why Panasonic declared 400 and 2500 as the dual gain values as those do not correspond to sensor behaviour, perhaps additional on sensor noise reduction only starts at those values or just wanting to make a marketing statement.
Back Illuminated 14bits Sensors
Here we have the S1H and S5 that have identical sensors and dual gain structure.
The metering behaviour on the S series is the same as the GH5s so all photo styles result in identical metering. The examples were at the beginning of this post so I am not going to repeat them here.
Now the gain reduction is 2 and ⅔ stops which is significant. After this is applied a strong log compression is performed. This means that when you have ISO 640 on the screen the camera is actually at gain equivalent to ISO 100 and when you have 5000 is at 640 resulting in very dark images. In the case of the S5/S1H VLOG does offer additional dynamic range not achievable with other photo styles.
Interestingly V-Log on the S series does achieve decent low light SNR despite the strong negative gain bias. Here we can see that the Log implementation can be effective however other photo styles that do not reduce gain may be a better choice in low light as gain lifts the signal and improves SNR. It is also important to note that the additional DR of VLOG compared to other photo styles is in the highlights so it only shows on scenes with bright areas together with deep darks this was noted on dpreview and other websites.
Should you use V-LOG?
It looks like Panasonic is tweaking the procedure for each sensor or even camera as they go along. The behind the scenes gain reduction is really surprising however it is logical considering the effect of a log compression.
Now we can also see why Panasonic calls the GH5s implementation V-LOGL as the level of log compression is small only 1 stops as opposed to VLOG in the S series where the compression is 2 ⅔ stops. We have also seen that V-LOG, at least in a digital consumer camera with sensor with integrated ADC, has potentially several drawbacks and those are due to the way a camera functions.
Looking at benefits in terms of dynamic range preservation:
GH5/G9 and front illuminated sensor: None
GH5s/BGH1 back illuminated MFT: 1 stop
S5/S1H full frame: 2 ⅔ stops
What we need to consider is that changing the gamma curve can also store additional dynamic range in a standard video container. Dpreview is the only website that has compared the various modes when they reviewed the Panasonic S1H.
A particularly interesting comparison is with the CineLikeD photo style that according to Panasonic can store higher dynamic range and is also not affected by the issues of V-LOG in the shadows or by color accuracy problems due to log compression. The measures of dpreview show that:
On the GH5s V-LOG has 0.3 stops benefits over CineLikeD
On the S1H V-LOG has a benefit of 0.7 stops over CineLikeD2
Considering the potential issues of noise and color bleeding in the shadows together with hue accuracy errors due to the approximation of the V-LOG implementation I personally have decided not to use V-LOG at all for standard dynamic range but to use it for HDR footage only as the decompression of V-LOG seems to have limited to no side effects. In normal non HDR situations I have shot several clips with V-LOG but I never felt I could not control the scene to manage with other photo styles and the extra effort for a maximum benefit of 0.7 Ev is not worth my time nor the investment in noise reduction software or the extra grading effort required. As HDR is not very popular I have recently stopped using V-LOG altogether due to lack of support of HDR in browsers for online viewing.
Obviously this is a personal consideration and not a recommendation however I hope this post helps you making the right choices depending on what you shoot.
This write up is based on my analysis on Panasonic V-LOG and does not necessarily mean the implementation of other camera manufacturers is identical however the challenges in a digital camera are similar and I expect the solutions to be similar too.
In December Olympus and Atomos have announced availability of ProRes RAW for Olympus OM-D EM1X and EM1 MKIII and Atomos Ninja V recorder.
This is the PDF of the Atomos release and this is the Olympus firmware update release in PDF.
This is definitely a step forward for ProRes RAW and also for the micro four thirds standard after the setback of Olympus withdrawal.
There has been very little information on the features and limitation and despite a few videos posted by Atomos and independent creative agencies nobody could really understand how the whole thing worked.
The video from Kauas a Finnish creative agency is here
It contains a lot of very dark scenes and the equipment used for the filming is suboptimal with lenses having a minimum aperture of f/2.8 which is clearly insufficient for the purpose.
I am always surprised when companies do such basic mistakes Olympus could have provided this agency with their f/1.2 primes and the clips would not be so noisy.
Atomos however has made test footage available for testing here.
So with those clips and my final cut pro expertise on HDR and ProRes RAW I got the opportunity to have a go at the sample. A short video illustrates the logic and the dynamics of working with such files:
When you use Olympus generated ProRes RAW files you are able to adjust the ISO/Exposure offset. What This seems to do is to move the black point of the clip without stretching the footage.
Adjustment of color temperature that would have been useful for underwater video is not available. Take into account that the adjustment correct temperature but not white balance as it does not have a tint slides.
As of today as per Apple technical note 211277 only Panasonic and Z CAM offer control of color temperature in post processing. So I would recommend to focus on those brands if you are particularly interested in this capability.
Another limitation of Olympus implementation is the crop factor. ProRes RAW reads individual pixels 1:1 so to the crop factors are:
This is because the pixels to 5184 horizontally are cropped to 4096 and 3840. Frame rate is limited to 25/25/30 fps.
Other issues include blanking of the camera EVF and LCD that will only show settings and nothing else and a limitation of internal audio recording to 16 bits. If you need 24 bits you need to plug the microphone into the Ninja V.
Overall I did not get the impression that this footage would really move things forward and right now I believe a 10 bit Log or Cine Gamma implementation that can accomodate things like sharpening and noise reduction will produce similar or even better results.
Will this make you want to buy an Olympus camera for this capability? Almost certainly not when you can buy a Z CAM and have more controls and options.
Will this make some people that already have an Olympus device buy a Ninja V instead of buying another camera altogether? I think some will however the majority of Olympus shooters are still focussed and right now there are not even many options for cages and mounts due to the lack of penetration in the video segment.
Nevertheless this effort should be commended because there are no glitches in the implementation like it happened with Nikon Z series and moves the goal post forward for the MFT segment. I expect Panasonic will have to release ProRes RAW for their new BGH1 that has the potential to be a very interesting device.
On September 30th 2020 the announced deal between Olympus corporation and Japanese Industrial Partners has been signed. Despite all sort of hysteria that is out there on the internet the deal structure is quite simple and there is good information released by Olympus Global on this link.
The Birth of OM Digital Solutions Corporation
The data provided tells us that the current head of the camera business will transfer to the new company that will be headquartered in Tokyo. OM stands for Olympus Maitani however the word Olympus does not feature in clear in the company name perhaps because Olympus corporation did not want to have any ambiguity or misunderstanding going forward on who is Olympus.
So the first indication is that Olympus as camera brand effectively ends when the deal completes on 31st December 2020. What continues is the legacy of Yoshihisa Maitani who originally invented the OM system.
What is included in the deal
This is the official text in the news release.
The agreement applies to Olympus’ global Imaging business, which includes all R&D and manufacturing facilities currently dedicated to its Imaging business. The New Imaging Company will continue to provide high-quality, highly reliable products. Built on a solid foundation, including the Zuiko and OM brands, which are grounded in optics and digital imaging technologies cultivated by Olympus over many years, the New Imaging Company will be appropriately positioned to further pursue new developments. Head of sales and marketing, R&D and designing departments for imaging products will be relocated to the headquarters of the New Imaging Company in Hachioji, Tokyo. Production will continue at the location in Dong Nai province, Vietnam, where imaging products are currently manufactured. The New Imaging Company will continue to provide customer support for the imaging products which have been manufactured and sold by Olympus. Following the transfer of the Imaging business, Olympus will concentrate on Medical and Scientific Solutions, in our ongoing efforts toward making people’s lives healthier, safer and more fulfilling.
So what does this mean? Today Olympus operates as a single company and the imaging business is included in it so they needed to work out what exactly they were selling. From that list this includes: • The Zuiko and OM (Olympus Maitani) brands • The R&D department • The Sales and Marketing Department • The factory in Vietnam And Olympus will focus on the medical and scientific business. The new OMD company will take on the after sales responsibility and warranty usually associated with provisions for repairs and returns.
What is NOT included in the deal
What is not included in the transfer is usually anything not specifically mentioned as included so a few considerations here expressing my view on the deal.
The factory in Nagano, Japan is not transferring but according to JIP news release will become a supplier to the new company. This is good for JIP as the factory in Vietnam is less than 3 years old and is in a market where workforce arrangements are more flexible than Japan. The Japanese factory that makes some components for Vietnam and in some cases full lenses will remain as supplier. Olympus also uses Sigma designs for some lenses like the 75mm 1:1.8 and the new 100-400mm 5-6.3 this will continue with OMD.
The Olympus Supply Chain is currently shared with the medical division there are a number of regional and local warehouse that will remain with Olympus together with any stock that is in there. All stock at customers (distributors or resellers) remains the property of those third parties. This is an important implication because it effectively means that OMD starts at zero stock and all the inventory sitting in those warehouses are Olympus corporation problem to clear, we have already seen aggressive promotions on OMD EM1MKII with a free 1.2 Pro prime lens. I bought one of those units and it was manufactured in February 2019 so clearly Olympus corporation distribution network is sitting on years of old stock.
The Olympus commercial network also remains with the seller and this means those entities will continue to trade in the respective markets until such time OMD decides to build their network, they may even decide to use distributors and focus on manufacturing and continue to use Olympus corporation or anyone else as they see fit, what is clear is that OMD is a manufacturing company not distribution. It will remain to be seen how the after sales services will be performed however this could simply mean customers get a replacement product or goods are sent all the way back to Vietnam for fixing or they establish 3rd party service centre to deal with this issue. Panasonic currently does that.
Future Direction of OMD
JIP has mentioned that they will focus more on video and on business customers this is good news as MFT strength really is in those two sectors. Panasonic has exploited that success while Olympus was only sticking to photos and suffering more the smartphone competition. We have seen an announcement that the newer OMD EM1 MKIII E1X will work in ProRes RAW with the Atomos Ninja a first step to get in that territory. Security is a big topic in MFT too as the back illuminated sensor in the GH5s is excellent in low light. Will JIP review the product range? For sure any situation like this sees a range rationalisation exercise. This means some SKU may be discontinued and some products in future roadmap never go to market. Olympus America website quickly put up a Q&A to that regards the three key answers are here, on the left what it says on the right what I think it means as the writing is not as black and white as you probably would like.
Will the Olympus brand name continue to be used?
While our official company name will be OM Digital Solutions, you can expect the Olympus brand name to stick around for the foreseeable future. Olympus branded products will continue to be available even after January 1, 2021.
The brands that will transfer are OMD and Zuiko. Olympus supply chain is sitting on a lot of old stock and currently all products being made are still branded Olympus, this will continue like that until the transaction closes. The Olympus brand will continue to be used also because the medical company continues. This does not mean that the cameras produced under JIP ownership will be branded Olympus and there are strong indications they will be called OMD as the word Olympus is associated with the medical company in the deal information and is not part of the new company name.
Will the new lenses announced as under development for sales in 2020 still be introduced?
There are no plans to change our product launch plans within 2020. Products that have been announced as under development will be introduced to the market as planned. You can find the most up to date information on product launches by visiting: http://www.getolympus.com
Olympus can only guaranteed what happens when they own the camera business. All things planned for Winter 2020 are going to happen if they happen before 31/12/2020 afterwards they do not know.
What is the future of Micro Four Thirds? Is there any change to the proposed lens roadmap? Will there be a future replacement for my Olympus product?
We are not able to comment on future product development at this time. For the most up to date information on Olympus products in the Americas, please visit: http://www.getolympus.com
The lens roadmap is an Olympus document what JIP will do with it is not something they know. In fact it is very likely to change if those projects are not going to provide a solid business case. They can also not comment on future cameras nor Micro-Four-Thirds are that is no longer their business
Also to be noted Micro-Four-Thirds is an open standard the fact that Olympus runs the four-thirds website does not mean anybody has to pay Olympus to make an MFT camera. So there is no issue of licensing rights connected to the MFT standard which only relates to AF and AE this is the reason you see many manual lenses not following the standard or not being listed.
The divestment of Olympus Imaging business is a sad moment for most as it marks officially the end of a legacy for what concerns Olympus corporation. With the performance that the business has had in the last years this was not avoidable. The new ownership will start with a streamlined business, a focus on manufacturing and a clean slate with no debts or old inventory to clear. OMD will also start with some good assets the IBIS and Auto Focus developed by Olympus are very effective and can play well especially if the new focus is on video. New more dynamic businesses like BlackMagic Design and Zcam are having success with the MFT format for video and this is an opportunity that Olympus missed entirely and hopefully the new company will grab. Will this be enough to save the MFT format from extinction? Definitely video is a more profitable segment where there are no smartphones that can really compete for those who want to be really doing a good job because the devices heat up, run out of battery and finally the editing process is still too complex that requires a workstation. I hope the OMD business can fully realise the full potential of MFT and provide a truly hybrid system, something Olympus failed to deliver with their still focussed product line. In the short term, and by this I mean the next two years, not much will change to the user experience, but we need to understand if Micro-Four-Thirds will have enough traction to continue for photography with new models or it becomes a video specialist segment.
I have been shooting MFT underwater since 2014 coming from compacts but I have also owned DSLR cameras for land use. As I initially focussed my underwater imaging on video I adopted Panasonic MFT cameras as they have an edge in terms of video use coming from Panasonic long established video and broadcast legacy.
Recently, just days before the divestiture announcement, I have purchased an Olympus OMD EM1MKII. I have decided on this camera as during lockdown I have been attempting pictures of birds in flight and the autofocus of my Panasonic G9, that I was using since February for land pictures, was not satisfactory.
I have since pondered if it made sense to switch to Olympus also for underwater use and I have considered the pro and cons of this choice compared to Panasonic semi pro models GH5 and G9. I thought of sharing my thinking with you so that if you are considering an MFT system as your next investment for underwater imaging you have a point of reference.
Note: I am only considering the top range Olympus cameras as others do not offer in my opinion any benefit over Panasonic range.
Strengths of OMD System
Olympus OMD Auto Focus system
At time of writing the OMD EM1 series and the EM5 Mark III use an Olympus specific on sensor phase difference detection auto focus system. Note this is different to DSLR phase detection and more similar to Sony hybrid AF system.
I found this system to be very effective with birds in flight once locked on the subject and much faster in locking on subjects as long as the background was clear; with this I mean this system still struggles if there is a busy background to acquire focus. In particular the CAF with tracking is very effective for birds that do not move too fast in the air or are about to take off from a fixed spot. It also effectively tracks at higher frame rate any type of object in motion. This system is superior to Panasonic CAF that is based on motion estimation for shots following the first one of the burst. More specifically it is harder to acquire focus for the first time with Panasonic and the following shots are estimated using a motion prediction algorithm without continuous autofocus. This feature is the one that sets Olympus camera that have phase detection AF apart from Panasonic and from more economic Olympus model such as the OMD EM10 series. Another useful feature is that in review mode it tells you what the camera focussed on.
Other features of OMD system for land use
If you shoot at night another very useful feature is live composition, this is very useful for fireworks or star trails but not effective for real astrophotography for which you need a star tracker or use stacking. Other features that are present in the newer EM1MKIII like starry AF are in my opinion not useful if you know how to focus on stars.
Olympus Housing Costs
As Olympus bodies are smaller and simpler the housing cost compared to Panasonic G and GH series is 30% lower this is material in the scheme of things as Panasonic Pro housing are almost as expensive as an APSC DSLR. This for me is the single most important factor.
Drawbacks of Olympus Cameras
Lack of on Screen Manual Focus Guide
The most evident one for macro shooters is the lack of on screen MF guide as displayed in Panasonic cameras. This very useful for macro but also for astrophotography and video as you know if your camera is at the macro or tele end. For macro underwater photography this means you know if you have hit the minimum working distance and maximum magnification so now you can focus on getting the shot using peaking.
Olympus does not offer a guide but you can pre-set a mode called Pre-MF to minimum distance however I found the on screen peaking to be really poor and ultimately getting less magnification in macro shots.
While Panasonic offers customisable Zebra on screen Olympus only offers a red and blue colouring and the levels only offer limited customisation on a 0-255 8 bits scale. This is OK for checking clipping in absolute but not good for specific exposure targets.
The video modes of the OMD are simply poor and the codec quality just good for your occasional video. The lack of exposure aid and support for manual focus make the whole video experience very very dissatisfactory.
With Panasonic you can set framing guides on the screen for 1:1 5:4 whatever you like without changing the image aspect ratio, this is useful if you want to frame a shot for a specific platform. Olympus lacks this feature entirely.
I can confirm that for underwater and land use I see zero difference in performance between my OMD EM1MKII and the GH5 in the range ISO 200-1600. It is true that the Jpeg settings are different and the color rendering is different for Jpeg however shooing RAW files this becomes irrelevant and I can’t distinguish the shots when the calibrated adobe profiles are used in Lightroom. I believe at some point that Olympus images were sharper however this was due to the images being better in focus when it comes to birds and subjects fast moving.
In terms of JPEG rendering Olympus choices are better for nature and landscapes with more saturated colours, for portraits I prefer the Panasonic rendering. Again those settings are not relevant for RAW files.
In my opinion the most attractive feature of Olympus cameras for underwater photography use is actually the reduced cost and size of the housing. While the extra strength are surely worth for land wildlife photography I truly do not think they make any difference underwater. For sure it would be better to do a field test, this so far has not been possible and if anybody gives me an OMD EM1MKII housing to test I would be very happy, however using the tools made available by Panasonic I do not get almost any shots out of focus and those there are blurred are because I forgot to change a setting on the camera.
For video I cannot recommend the Olympus system at all, Panasonic is way ahead on this on a number of accounts.
In conclusion if you are 100% focus on photography and just take an occasional video the OMD system is light more compact and less expensive. It will not give any edge to your images as the sensors are identical. If you shoot a mix of video and photos the choice is Panasonic. Rest assured none of the AF strength of Olympus will improve your hit rate, if your shots are blurred you are likely using the wrong settings with your camera. The housing costs tho are higher and the rigs are less portable.