Environmental Conditions joy and despair of the photographer

A few weeks ago I went diving in Swanage with BSOUP the British Society of Underwater Photographers that I have recently joined.

I was looking forward to some local diving so when I found out that they were organising a trip I managed to get on.

I drove there the night before and I was number two on the pier the next day.

It was a deceiving clear morning with perfect conditions on land.

I had two cameras one in the housing and one for land use so I took a few snaps.

Once parked on the pier I was informed by two friends that dive locally all the time that it was better to wait when the water level was a bit higher.

At that point it did look like a great day however there was a bit of wind.

I had my GH5M2 with the Panasonic 45mm macro that I acquired last year and has become my favourite macro lens.

I jumped in the water one of the first to find out the visibility was well maybe 1 meter? I could not see the LCD screen of the camera due to the suspended particles and had to use the viewfinder

One of the first things I say was this corkwing wrasse with a massive parasite near its eye.

Unfortunately I did not have a snoot or strobes suited for the challenge so I spend the first dive training myself on how to get the least amount of back scatter. Mind you when there are particles you will have backscatter not matter what you do.

Static subjects are ideal for testing so I had a go at some really simple stuff.

And again some anemone the object was to get the cleanest possible shot.

When I was reasonably happy I moved to some more interesting subject I gave up on blennies as I knew everyone would have shot some and besides my strobes were not the best for the situation and I found a cooperating cuttlefish.

I can tell you that to get this clean shot it took me quite a while but on reflection despite being very low I could not even see a hint of the surface so bad the conditions so I decided to get really close.

I wanted to emulate a profile of a person or perhaps an elephant not sure but I took a number of shots waiting for the tentacles to be in the right position and this is my best shot for the day.

I would say it is quite creepy but after all I had something decent and when I presented the shot in the club review at the sailing club it got some good feedback.

Now with that in mind let’s have a look at some shots taken in clearer water this is from Sorrento Peninsula.

Blenny Gold

You can see that clearer water improves contrast and sharpness as you would expect however as the UK shot was very close the gap is not as big.

And this is a shot from last time I was in the red sea

This is super macro so again suspended particles are not as important.

However if we look at a mid-range shot similar to the whole cuttelfish the situation is very different.

Here we are in Italy.

The Look

And finally here in the red sea.

Napo Lips

For as much as we may love our local dive site there is a degree of adaptation but also a restriction on the variety of shots we can take.

When I was working as resident dive instructor I remember the guidelines we were passed one was really funny and said:

“if the visibility is crap you don’t say that to the guests what you say is today we are going to focus on macro” then you make sure you choose a site where there is some.

I am looking forward to my boat in the Red Sea end of July remember if you follow me on instragram there may be some voucher codes to be used for discount.

If like me you have been trying to make the most of your local dive site you deserve to get yourself in clear water where you can actually see further away than your arm. Of course we do have some good days in England sometimes 5 even 8 meters but I tale Egypt and their 25+ meters any day of the week!

A closing thought on conditions and land photography, in fact even if visibility is not an issue most times unless you have fog, overcast days, excessively clear days do not make great land pictures either so we can say we are always on a quest chasing light and conditions.

Mirrorless Cameras Opportunity or Necessary Evil?

I believe we have finally got to the point where users are moving from DSLR to Mirrorless camera in mass. The release of the recent Nikon Z9 and Canon R5/R3 has definitely shifter land photographers to mirrorless.

Underwater photographers have been lagging mostly because of optics compatibility more specifically lack of compatible fisheye options for mirrorless. Some classic lenses like the Tokina 10-17mm do not work properly when used through an adapter and releasing fisheye lenses has not been a priority for Canon or Nikon. The good news is that 1st party full frame lenses like the 8-15mm fisheye do work through an adapter and generally all DSLR optics 1st party can be adapted to a mirrorless camera of that brand.

I have sold my last DSLR in 2016 and generally never looked back. I believe this can be a harder move for a bird shooter or a sport photographer but the latest flagship cameras have performance for everyone.

EVF vs OVF

In terms of image quality there are no significant differences between a mirrorless camera and a DSLR camera. Improvements in image quality are mostly related to sensor improvements regardless of the system that runs that specific sensor. There are however some significant differences between an optical viewfinder and an electronic one.

Nikon Z7 and D850 have the same sensor and identical performance

An optical viewfinder literally means looking through the lens with your eyes, the primary benefit of an optical viewfinder is the lack of lag. Some people say that optical viewfinder have higher dynamic range but that is not actually correct as an optical device does not really have dynamic range limitation and neither is true that the human eye has 30 stops of dynamic range and all those fantasies.

The key problems of an optical viewfinder is that when is dark you cannot see things until your eye adapts and this happens slowly so most DSLR users switch to live view which essentially means using your DSLR camera as a mirrorless camera and watching a video stream on your LCD.

The other ergonomic difference is that you don’t know how your shot turned out until you review it after you shoot as the OVF can’t play back images being an optical device only.

An electronic viewfinder instead is nothing else than a micro LCD or OLED screen that is showing you a video of what is going on and is also able to playback the images.

This has the great benefit of not needing to take your eye off the viewfinder as the image is played back as soon as you shoot. The price to pay is a small lag between reality and what you see on your EVF.

While an OVF is real time an EVF has a lag that depends on how fast the sensor is being read. This can mean a delay of more than 30ms on very cheap cameras with just an LCD down to 5ms for the fastest reading Nikon Z9 and the likes. In general below 20ms is normally good enough for underwater use but for fast moving subjects like birds in flight less than 10ms is better.

The other benefit of an EVF is that in dark scenes it can boost the display so you can see better than your eyes in the dark.

Electronic Viewfinder Myths

One of the biggest myths about EVF is that they give you a what you see is what you get view of the image before you take it.

This is unfortunately untrue and it is important to understand why.

In a photograph we have two exposure settings the aperture and the exposure time. ISO maps the amplification of the system and is not an exposure setting however it can be useful to brighten an image that is too dark by amplifying electric signal after light has been converted into current by the sensor.

Normally a camera operates with the lens wide open and with a fixed exposure time determined by the sensor readout frame rate.

Imagine that your camera has an f/2.8 lens and the sensor is reading at 60 frames per second. You have set your underwater shot for f/11 1/250. However your camera will not close the aperture to f/11 until you press the shutter and it is actually operating at 1/60 exposure time.

In order to simulate the image the camera will try and adjust the brightness of the EVF to make it lighter or darker so that you can see properly what you need to shoot. This has actually nothing to do with the shot that will come out.

Some cameras Sony, Canon, Nikon and Panasonic have a preview or exposure simulation setting that will close the aperture to the value you chose and simulate the shutter speed chosen in the video displayed to your on screen and if you operate in full manual the display will actually change brightness as you change your exposure settings. However this does not actually show an image exactly identical to the one you will shoot because of the limitation on the exposure time. It will show something close to that image and only if you select the option to simulate the exposure. Some cameras are actually unable to perform a full simulation and the brightness of the EVF will not be adjusted and may give the impression the image is very bright when it is not.

If you shoot with flash of course all of this goes out of the window as the camera assumes the flash will always sort things out and the display won’t be affected unless you force it too but of course it won’t be any near to the image you will take. In essence you need to wait until after you have taken the image to see very much like a DSLR.

Are mirrorless better for the underwater photographer?

Despite beliefs of hard core DSLR fans mirrorless are a better option for the underwater photographer for a number of reasons:

  1. The EVF lag is no longer an issue as it used to be on old compact camera and the refresh is faster than your eye and brain can react to
  2. You can see the image preview without having to take the eye off the viewfinder
  3. If you need to shoot in ambient light you have exposure aids that will make sure your image is correctly exposed without trial and error

Is there a disbenefit to EVF? The EVD is a small screen and needs power to run this means that given the same battery capacity a mirrorless camera will have less autonomy however almost all decent cameras have over 300 shots autonomy and can get easily to 500+ so really there is no reason to hold back to DSLR.

In 2022 it is definitely time to move on.

If you are a DSLR shooter and see other disbenefit from a mirrorless camera leave a comment I want to hear from you.

Is the GH6 worth the upgrade?

After a few months of using the GH6 is time to answer the question pretty much every GH5 user is asking now.

The answer as always is … it depends. I hope this article will help you clarify your thinking.

Noise Performance

I have done a number of tests on all the GH5 and GH6 series cameras including the original GH5, the GH5S, the GH5M2 and the GH6.

While many people talk about dynamic range most only care about noise and in particular if this will show in your footage or not.

Unfortunately read noise accurate calculation are only possible for RAW image files not video. Video has an additional issue which is temporal noise.

As noise is random by nature each frame will have its own noise and the changes in noise generate that flickering effect that everybody hates. This is called temporal noise and to an extent every camera has it.

Obviously if you have less noise you will see less flickering but all cameras will have some.

The other discussion that has been going on forever is that large pixels are better for low noise, this is also not true as more pixels can be added and noise averaged out. So the only thing that matters is sensor size, sensor construction and the sensor coating.

The original GH5 did not have a great coating so when the GH5M2 was released sharing the same coating of the G9 most people were saying well it won’t matter much while instead it does.

The benefit that the AR coating brings to the GH5M2 compared to the original GH5 is around 2/3 Stops which is not negligible.

VLOG Implementation

The other difference among the various GH cameras is how VLOG is implemented.

In the GH5/GH5M2 VLOG is simply a curve and achieves no major benefit compared to other photo styles but it avoids you clipping highlights at expense of additional noise. This noise is managed overexposing 1 stop.

In the GH5s/GH6 VLOG applies underexposure behind the scenes of 1 and 1 1/3 stops so dynamic range is maximized. Both cameras have strategy to deal with noise. The GH5S applies noise filtering the GH6 scaling the net result is that VLOG in those camera is better than shooting something else.

Analysis

Using a mix of read noise on RAW files and calculation of how noise is managed I have created the following chart that shows how noise goes at bit level when ISO goes up.

Here you can see all the cameras I think this graphic explains pretty much what happens at high ISO. For low ISO you need to take into account shot noise and my analysis is not able to evaluate that however this will make a small difference to the evaluations.

So lets go into the specifics

I am a hybrid user I want the best of both worlds which camera is better for me?

The GH5M2 is currently the best camera in this category, it offers the best still image performance, it has IBIS and video is very good and can be improved with an external recorder if you wish. It also records 8 bits which is fine for those who do not want 10 bits at all costs and uses SD cards. The dynamic range of a still image is the best of all GH series cameras as seen on photonstophotos. Remember that RAW files are not denoised or scaled like video.

I am a GH5 video user should I buy a GH6

Assuming that you shoot vlog because if you don’t any camera works just fine the answer is yes unless you are always at ISO 400 with your GH5 and do not want to buy more ND filter the GH6 is a significant step forward.

You need to evaluate however if you need all the GH6 offers.

I am a GH5S video user is the GH6 for me?

While the GH6 performance is better than the GH5S in the high ISO zone at low ISO is worse. The GH6 has IBIS and all the features the GH5S has however it is limited to 12800. The GH6 also produces 25 megapixels photos but as a GH5S user this was probably not important.

So the answer is yes if you don’t need really high ISO (>12800).

I am a GH5M2 video user is the GH6 for me?

If you don’t mind ND filters, use the camera in both daylight and low light and you need any of the features like 120fps 4k then the answer is yes.

Conclusion

The GH5 has been a very competitive camera and the GH5M2 further improved on it. The GH5S has its own niche and all of those are strong proposition. When looking at the GH6 the key criteria is that you are focused on video and that you need all the codecs and feature the camera has.

I think this video sums it up nicely

Panasonic GH6 Video and Still Performance

I have had the GH6 now for a bit more than one Month and it is time to get to conclusions in terms of the image quality in both photo and video.

In order to do that I have ran the GH6 side by side with the GH5M2 so far in my opinion the best hybrid Micro Four Thirds camera.

Video Performance

There have been a number of reviews online with regards to the GH6 video mode and for me two have stood out.

The first is the review from CineD and the second is from CVP

You do need to take into account a combination of factors when you look at video because the functionality and the camera image pipeline are what makes the video.

In general terms when it comes to functionality and codecs offered the GH6 is simply incredible. I have taken the opportunity to start bird video project and that would have not been possible with the GH5M2 or any previous GH series camera.

You can follow my work as it develops here

My latest land wildlife project is about Grey Heron nesting

For the first time I am shooting in VLOG an entire project and this is due to the implementation in the GH6.

VLOG Implementation

In the GH6 the implementation of VLOG is similar to what is done in the GH5s and the S series. So when you shoot in VLOG the camera is applying a negative adjustment of 1 1/3 stops behind the scenes.

This means when you are shooting at the 250 base ISO the camera is actually internally working at ISO 100.

In addition the GH6 no longer underexposed middle grey behind the scenes and it is spot on the grey card and in the RAW linear data.

In addition we now have a Dynamic Range Boost functionality that blends two frames one at High Gain and one at Low Gain to give you additional headroom in the highlights.

The result is that when you look at VLOG you have increased performance with dynamic range boost on from ISO 2000 and very strong dynamic range up to ISO 6400.

I have run some read noise tests using my astrophotography software and then applying the exposure shifts I come with the above result. Take into account that dynamic range in the GH5M2 is clipped on the highlights at 1 stop less so in reality although the graph seems to indicate that the GH5M2 at ISO 400 has more dynamic range this is not actually the case. However that is true is that up to ISO 1600 when the GH6 has dynamic range boost OFF the GH5M2 outperforms the GH6 in video.

I have shot side by side video and I will post on my YouTube channel some time soon.

However the first conclusion is:

if you do not need 4k120fps or 5.7k and don’t exceed ISO 1600 the GH5M2 is a better choice

What does this actually mean and how low light can you go? In practical terms f/2 1/60 ISO 1600 means 17 lux middle grey typical of floodlight buildings exteriors so not that dark but not that bright either. An indoor lounge with decent lights will have this level of illumination. Of course you can put a strong ND filter on the GH6 and enjoy more dynamic range however this has a number of other side effects.

The second conclusion is

Using dynamic range boost gives you 1 1/3 stops improvement on the GH5M2 from ISO 2000 and more highlight headroom but worse noise performance at low ISO

So what is the use case that will definitely favour the GH6? Typically need for high quality high frame rate formats and decent low light performance. The camera does pretty well up to ISO 6400 in VLOG.

If you don’t use VLOG there is noise reduction in camera so although it looks clean the details is not anymore there. So personally I would use VLOG when possible with the GH6.

Photographic Performance

When it comes to photos the design choices of the GH6 backfire. The camera has incredibly high levels of read noise as per this graphic.

Read Noise vs ISO

In addition the read noise is higher in the low ISO before it turns to ISO 800 when dual gain output is in action.

This has of course a direct impact on the theoretical maximum dynamic range.

Maximum Dynamic Range

Here you can see that at values up to ISO 640 the GH5M2 really has an edge and the improvement of the GH6 is really limited to the region between 800 and 3200 the benefit is modest at best 0.5 stops.

So the third conclusion is:

If you are interested in the best photographic dynamic range in micro four thirds the GH5M2 (and the G9) are better choices

As an example those two images shot outdoor show that in effect our eyes do not really see read noise in a bright scene and once scaled the two camera cannot be taken apart. However if you had shot a long exposure at low ISO you will see grain with the GH6 under ISO 800.

For how hard I try I could not tell the difference between the two images above once processed and scaled.

Final disclosure all my figures look at pixel level noise and dynamic range. Scaling to a common size as shown by the image above will benefit the GH6 more as it has higher resolution but the difference is no so large that the data above is not valid so in general all I said above holds.

I have provided test files to Bill Claff of PhotonstoPhotos and he will publish more reliable and scientific results in due course.

We are both puzzled by the GH6 design and are waiting for another raw converter support to reconfirm however the triangulation of my data with other sources holds so I am quite confident of what I wrote here.

Matching GH5M2 and GH6

Today I went out with both the GH5M2 and GH6 to shoot some roll for my new project.

I have tested the GH6 in my light box and surprisingly CineD2 has changed it is now correct but also more saturated. So to avoid issues I shot both cameras in V-Log. Most readers know I am not a fan of log footage however today they conditions were pretty decent so I was at base ISO and I did not mind closing the aperture as I was shooting birds and landscape.

Lumix GH5M2 set up

I shot the GH5M2 in default settings in VLOG without manipulating exposure. The camera has a tendency to overexpose and I let it do it.

I set up color temperature to daylight to avoid differences and shot All Intra 30fps at 400mbps on a tripod. It was windy at times.

Shot sunrise then the pond that is the target for my long lens work.

Lumix GH6 set up

I used the same settings of the GH5M2 but shot at 60 and 120 fps using the new codecs of the GH6. I did not use dynamic range boost.

As I used a very long lens I had set up a plate for the tripod but I still got occasional shake as I was fidgeting the remote shutter.

As the camera has a lag to start recording I ended up shooting many blanks. I realised the lens is far too long for birds in flight but good for detail shots.

Putting it together

I combined footage in Final Cut Pro and used the standard VLOG to V709 LUT. I then added vibrancy and sharpness.

Each scene was corrected for exposure individually not pre-cooked LUTs were used.

This is the resulting video

I used slow motion from the GH6 at 50% and 25% speed this is really a great feature for wildlife. The only thing missing is a pre-roll

All in call the cameras when the GH6 has dynamic range boost off look very similar and this is because GH6 levels are clipped.

Let me know what you think

Panasonic GH5M2 and GH6 HDMI Lag Optimisation

Key Facts

  • The camera live view is one frame behind due to the image processing pipeline, faster refresh rates reduce delays
  • HDMI latency does not depend on cable length
  • Most monitors have low latency
  • HDMI can carry audio and video and those need to be synchronised: if one of them is slower than the other a delay is introduced to match up
  • Resolution plays a role but not as important as others

GH5M2 and GH6 Lag between LCD and HDMI

  • The camera LCD has a resolution of 960×640 pixels and a refresh rate of 60 fps that can be reduced to 30 fps
  • When recording the camera shows the live view on the LCD with a delay of c 1 frame from real life
  • If you go into the menu HDMI Recording Output and set Sound Output  OFF you can see the real lag between the LCD and the HDMI
  • This lag is typically 2 frames from the LCD 
  • As frame  rate drops the lag increases
  • When the Sound is disabled the lag of the GH6 is generally better than the GH5M2
Measurements Results

Video Tutorial with my recommended settings

Items shown in this video

1. Atomos Shinobi: https://amzn.to/35DmFhD

2. Manfrotto 290 Xtra: https://amzn.to/3sSYggF

3. Manfrotto Light video head: https://amzn.to/3vTCHPc

4. Smallrig Monitor Mount: https://amzn.to/367f22z

5. Smallrig HDMI cable: https://amzn.to/3sVwNe9

6. Panasonic GH6: https://amzn.to/3HTUZlv

7. Panasonic 10-25mm 1.7: https://amzn.to/3KtxAcn

8. Atomos Ninja V: https://amzn.to/3MEKia0

HDMI Optimisation Wrap Up

  • Monitoring has acceptable delays from live time 50-150ms
  • Audio recording introduces a delay of 65ms on the GH5M2 and 35mm on the GH6 
  • The GH5M2 lag  of 190ms in 24p is too high and should be reduced to 160ms
  • There is a bug in the 30p mode on the GH6 as the lag is higher than 24p this needs to be corrected

Panasonic GH6 Power Solutions

The GH6 has the same USB power capabilities introduced in the GH5M2.

In this video I show you what I use with my cameras.

Initially with the GH5 I could only use a dummy battery kit and this will continue to work however it may have challenges with mechanical shutter or very high bitrate codecs of the GH6.

Therefore the recommended solution is a PD Power Bank

Pay attention to the checks you need to do as your power bank needs to deliver 9V 3A which usually means at least 45W better 65W

US

1. Dummy battery kit: https://amzn.to/3sFarxp

2. 65W PD Power Bank: https://amzn.to/35Kh6gW

3. Cheap USB Power Bank: https://amzn.to/3IVhM1u

4. USB C Cable: https://amzn.to/3tnsreQ

UK

1. Dummy battery kit: Currently Not Available

2. 65W PD Power Bank: https://amzn.to/3KgGfih

3. Cheap USB Power Bank: https://amzn.to/3HBGDGk

4. USB C Cable: https://amzn.to/3sGBmcj

Panasonic GH6 my preliminary key observations for Underwater use

I was able to have a 1 hour hands on session with Lumix yesterday and try some of the GH6 features.

Key points

  • Beautifully engineered machine
  • 1 stop dynamic range increase appears to be true
  • LCD design with tilt will make easier to see underwater
  • Records ProRes 422 HQ to CFExpress Card
  • Support HDMI 2.1 (playback only)
  • Battery same as the S5 and newer GH5M2
  • Battery consumption 25 to 35% higher in MP4
  • Significant HDMI lag if you use a recorder (1/4 of a second)
  • Will record to USB with a future firmware update
  • Will record prores raw externally with a future firmware update
  • No battery grip

I am going to do a longer write up once I have tested the camera for land wildife use however I have the following concerns

  1. What is the real battery life when you record ProRes to card instead of the low quality MP4, will it last at least one dive?
  2. HDMI lag is horrible just received confirmation that HDMI recording is capped at 4K resolution This proved to be a red herring as the lag is decreased from the GH5 series see here https://interceptor121.com/2022/03/10/panasonic-gh5m2-and-gh6-hdmi-lag-optimisation/
  3. The lag of the HDMI can be reduced if you use only a  monitor with a few tricks and it only needs HDMI 1.4
  4. The USB recording will be powered by the camera and the battery is already small

My recommendations for a professional grade housing would be:

  • Recording to card either 4K@60 or 5.7@30 depending on your use case
  • Optional monitor to run in 1080p to reduce lag HDMI 1.4 is sufficient
  • PD Power bank inside the housing so you are sure you will not run out for an entire day of shooting

For photography a classic housing would work but then who is going to get this just for photos?

Stay tuned for more information. If there is something you want to know about the camera use the comment feature here.

Panasonic GH5M2 and S series Demystifying Movie recording settings 2022 Update

 

In 2018 I wrote the original article as I had acquired the GH5 and I was faced with a ton of non-sense on which format to use when I was shooting video. With the S series software stack Panasonic has made some changes to the options available and I thought it was about time to refresh the original article. As Before I will focus my analysis on 4K video and ignore other formats. This time I will be looking at the NTSC standard of 29.97 and 59.94 frames per second. This is simply because today majority of content produced by Panasonic consumer digital cameras is consumed online and all computer screen work at 60 Hz refresh rate so shooting anything different than 30 or 60 will result in choppy video. This presents some challenges if you are in a PAL zone and are shooting under artificial lights however for the purpose of this article I want to just ignore this issue, obviously you could shoot 24 fps and hope in a 24 – 30 conversion which is scatty of course. For simplicity I will refer to 30 and 60 fps and not exact values.

Today we have 5 settings for UHD 

  1. 200 Mbps 420 10 Bits Long GOP 60 fps
  2. 150 Mbps 420 8 Bits Long GOP 60 fps
  3. 100 Mbps 420 8 Bits Long GOP 30 fps
  4. 150 Mbps 422 10 Bits Long GOP 30 fps
  5. 400 Mbps 422 10 Bits All-Intra 30 fps.

The last option is only available on the GH5 series and on the S1H. The first option is only available on the S series and the GH5M2. 

Long GOP vs All Intra

The difference between Long GOP and All Intra is that in the Long GOP what is encoded is a group of pictures (GOP) and not separate individual pictures.

Within a Group of Pictures there are different type of frames:

  • I (Intra coded) frames containing a full picture
  • P (Predictive coded) frames containing  motion interpolated picture based on a prediction from previous frames
  • B (bi-predictive coded) frames containing a prediction from previous or future frames

It is important to note that frames are not stored sequentially in a GOP and therefore the GOP needs to be decoded and the frames reordered to be played, this requires processing power.

The reason why H264/HEVC is very efficient is that within a group of picture there is only one full frame and the rest are predictions clearly if the prediction algorithm is accurate the level of perceived quality of long GOP is very high and similar to All-Intra clips.

This is the reason why comparing All Intra and Long Gop using static scenes or scenes with repetitive movement that can be predicted very accurately by the codec is a fundamental error.

So which format should you choose?

In order to understand the workings we need to dig deeper into the structure of the GOP but before doing so let’s evaluate the All-Intra codec.

AVC All-Intra explanation

This codec records at 400 Mbps so with 30 fps this means circa 13.4 Mbits per frame or  1.67 MB per frame and there is no motion interpolation so each frame is independent from the others. The implementation of All-Intra of the GH5 does not make use of CABAC entropy but only CAVLC coding is used, this makes the resulting files easier to read and to edit. The idea of All intra is that you don’t require powerful hardware to edit without conversion in an intermediate codec. However based on my experience this is not entirely through and you need a decent GPU to play it back and edit real time without issues.

If you consider a Jpeg image of your 3840×2160 frame on the GH5 you see that it stores around 4.8 MB per image because there is no chroma sub-sampling so if you wanted to have exactly the same result you would need to use ProRes 4444 to get a comparable quality (this not even taking into account that Jpeg are 8 bits images).

Video uses chroma sub-sampling so only part of the frame contain colours at a given time. Apple in their ProRes white paper declare that both ProRes 422 and 422 HQ are adequate to process 10 bit colour depth and 422 sub-sampling however they show some quality differences and different headroom for editing. If you count 50% for 4.2:0 sub-sampling and 67% for 422 you get around 2.34 MB and 3.5 MB frame sizes that correspond to ProRes 422 and ProRes 422 HQ individual frame sizes.

it would appear that All Intra 400 Mbps would fall short of Apple recommended bit-rate for 422 10 bit colour however practical tests show that AVC All intra at 400 Mbps is perceptually identical to ProRes 422 HQ and uses much less space. We also did some SNR measures time ago with the friend Paal Rasmussen and we did not find significant improvements shooting ProRes 422 HQ vs All-I on card.

Long GOP Codecs

Coming back to the other recording quality option we still need to evaluate how the various long GOP codecs compare relative to each other.

In order to fully understand a codec we need to decompose the GOP into the individual frames and evaluate the information recorded. If you look on Wikipedia it will tell you that P frames are approximately half the size of an I frame and B frame are 25%. I have analysed the Panasonic GH5M2 clips using ffprobe a component of ffmpeg that tells you what is exactly in each frame to see if this explains some of the people claims that there is no difference between the settings.

Link to Panasonic on the H264 implementation is here: documentation

There is unfortunately no documentation of the HEVC implementation that I have found to date.

200 Mbps 420 10 Bits Long GOP 60 fps Analysis

An analysis with ffprobe shows a GOP structure with N=30 and M=1 where N is the length in frames of the group of pictures and M is the distance between I or P frames.

This codec does not have B frames but only P frames.

Analysing a set of I frames of a fixed subject at 60 fps resulted in a frame size of 1.16MB for the I frames. This value is quite low however we need to understand that HEVC is much more efficient than H264. 

I shot this test video time ago comparing the recording of this codec with a Ninja V in ProRes 422 HQ. As you can see no major differences however I have not pushed the grading in the clip.

The speed ramps in this video use this codec

 

150 Mbps 420 8 Bits Long GOP 60p Analysis

An analysis with ffprobe shows a GOP structure with N=30 and M=3 where N is the length in frames of the group of pictures and M is the distance between I or P frames.

So each Group of Pictures is made like this

IBBPBBPBBPBBPBBPBBPBBPBBPBBPBB before it repeats again.

Analysing a set of I frames of a fixed subject at 30 fps resulted in a frame size of 1.26MB for the I frames.

One very important aspect of the 150 Mbps codec is that as the GOP is double the length of the single frame rate 100 Mbps codec there are the same number of key frames per second and therefore it is NOT true that this codec is better at predicting motion however the additional frames result in better slow motion performance than what is done in software in majority of cases.

100 Mbps 420 8 Bits Long Gop 30 fps Analysis

An analysis with ffprobe shows a GOP structure with N=15 and M=3 where N is the length in frames of the group of pictures and M is the distance between I or P frames.

So each Group of Picture is made like this

IBBPBBPBBPBBPBBP before it repeats again.

Analysing a set of I frames of a fixed subject at 30 fps resulted in a frame size of 1.49MB for the I frames which is the highest if we exclude All I.

150Mbps 422 10 Bits Long Gop 30 fps

An analysis with ffprobe shows a GOP structure with N=15 and M=1 which means this codec does not use B frames but just I and P frames so the GOP structure is as follows:

IPPPPPPPPPPPPPP before it repeats again.

Analysing a set of I frames of a fixed subject at 30 fps resulted in a frame size of 1.25MB for the I frames.

H264 Codec Ranking for Static Image Quality UHD

So in terms of absolute image quality and not taking into account other factors the Panasonic GH5M2 and S series Movie recording settings ranked by codec quality are as follows:

  1. 400 Mbps 422 10 Bit All intra 30 fps (1.67 MB per frame)
  2. 100 Mbps 420 8 Bit Long Gop 30 fps (1.49 MB per frame)
  3. 150 Mbps 420 8 Bit Long Gop 60 fps (1.26 MB per frame)
  4. 150 Mbps 422 10 Bit Long Gop 30 fps (1.25 MB per frame)

The 100 Mbps  and 400 Mbps codec are marginally different with the 150 Mbps long GOP really far away.

Note that as the technology is different I cannot directly compare the new 200 Mbps codec however based on visual impression and ability to grade I would recommend this over the 150 Mbps 420 8 bits

Conclusion

If you have a camera that has the 400 Mbps All Intra this remains the best format  to use. V90 cards have dropped in price and are now available up to 256 GB. Unfortunately this option is only available on the GH5 series and on the S1H.

If you have a camera that does not have the All-I you can of course purchase an external recorder that in some cases will allow you to shoot RAW however this is not necessarily going to give better image quality and will definitely extend your processing time.

My revised advice, if your camera does not have the ALL I and you don’t have an external recorded, is as follows:

  1. Use the 100 Mbps Long Gop codec it is very efficient in the compression and the perceived quality is very good. You need to get the exposure and white balance right in camera as the clips may not withstand extensive corrections. There is a risk with footage with a lot of motion of some errors in motion interpolation that can generate artefacts but this based on experience is not very high. 
  2. Use the new 200 Mbps HEVC for double frame rate it is not hard to process as HEVC 10 bits has hardware acceleration on all platforms.

Generally there appears to be no benefit using the internal 422 10 Bit codec nor the 420 8 bit double frame rate due to the limitations of the GOP structure, in addition the lack of hardware acceleration for H264 10 bits means you will need to convert the files for editing and they do not open with standard programs or load on phones or tablets. The same is true for All Intra but at least you can edit it ok.

To conclude this is a summary table with all key information

Screenshot 2022-01-24 at 18.01.50

Additional Considerations

A certain number of GH5 users have upgraded to the S5, I was one of them until I sold the camera after 1 month of using and after buying a Ninja V. If you are a Panasonic S1/S5 user you need not only to contend with recording time limits but also with lack of codecs on the camera to fully use the potential that it has. You need to add an external recorder to really see the benefits because in real life situations you are not shooting a step chart so the dynamic range is destroyed by compression quality and errors and SNR drops. It would be interesting to test how does the GH5M2 400 Mbps compare with one of the S cameras using the 150 Mbps 10 bit codec but this is not something I did. I would only warn everyone going down that path that you may get less than what you think and you may require additional hardware to get there. Take also into account that S series only shoot 50/60 fps in APSC/Super35 mode and that in full frame mode there is a substantial amount of rolling shutter that makes pans and tilt practically not possible.

Panasonic GH5S Review – Conclusion

I hope you found the tests useful and I guess the key question is:

Is the GH5S still worth it in 2022?

I have prepared a comparison table with the GH5 and GH5M2 using data available and for noise my subjective measurements supported by the video evidence.

As you can see from the table the GH5S still has some unique features:

  • RAW support (ProRes RAW and BRAW)
  • VLOG performance
  • High ISO performance straight out of camera
  • Slightly lighter and better battery life

So if any of the above are essential to you there is still a case for the GH5S.

However the GH5M2 with Neat Video will cost you $1,699+$129=$1,828, for sure you will have to work without Vlog and RAW but you will have many other benefits and you will not need a recorder to shoot 50/60 fps bringing the overall cost down significantly.

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