Tag Archives: filter

Matching Filters Techniques

The issue is that the Ambient light filters are set for a certain depth and water conditions and does not work well outside that range. While the idea of white balancing the scene and getting colour to penetrate deep into the frame is great the implementation is hard.

Thinking about Keldan we have a 6 meters version and a 12 meters version as listed on their website. The 6 meters version works well between 4 and 12 meters and the other between 10 and 18. At the same time the Spectrum filter for the lens works down to max 15 meters and really performs better shallower than 12 meters.

With that in mind it follows that if you plan to use the spectrum filter -2 you are probably getting the 6 meters ambient filters. So what happens if you go deeper than 12 meters? The ambient light filter is not aligned to the water ambient light and the lights start to look warm this is not such a bad thing but can get bad at times.

You can of course white balance the frame with the lights however this becomes somewhat inconvenient so I wanted to come out with a different technique. In a previous post I have described how to match a lens filter to a light/strobe filter. Instead of matching the light filter to the ambient light I match the filters on land between each other in daylight conditions to obtain a combination that is as much as possible neutral. I have done this for URPRO, Magic Filter and Keldan Spectrum filter and worked out the filter that when combines give a neutral tone.

Magic filter combined with 2 stops cyan filter giving almost no cast

This tone tends to emulate the depth where the filter has the best color rendition. So in case of Keldan this is around 4 meters and so is Magic with URPRO going deeper around 6-9 meters.

The idea is that you can use the filter without lights for landscape shots and when you put the lights into the mix you can almost shoot in auto white balance or set the white balance to the depth the two were matching. I wanted to try this theory in real life so I did 3 different days of diving testing the combination I had identified the results are in this video.

The theory of matching filters worked and the filter more or less performed all as expected. I did have some additional challenges that I had not foreseen.

Filter Performance

The specific performance of a filter is dependant on the camera color science. I have had great results with URPRO combined with Sony cameras but with Panasonic I always had an orange cast in the clips.

Even this time the same issue is confirmed with the URPRO producing this annoying cast that is hard if not impossible to remove also in post.

The Magic filter and the Spectrum filter performed very close, with magic giving a more saturated and baked in image with Keldan maintaining a higher tone accuracy. This is the result of the design of the filters: the Magic filter has been designed to take outstanding picture better than life, the Spectrum filter has been designed using tools to give accurate color rendition. What it means is that the magic images look good even in the LCD while Keldan are a bit dim but can be helped in post.

Looking at the clip in the first 3 and half minutes you can’t tell apart Magic and Spectrum down to 9 meters, with the URPRO giving consistent orange cast.

Going a bit deeper I realised you also need a scenario where you are swimming closer to a reef and want to bring some lights in the frame because you are outside the best working range of the filter. In order to avoid excessive gap when approaching the reef I had stored white balance readings at 6 9 12 15 meters so when I had a scene with mixed light instead of balancing for say 15 meters and then having an issue with the light I used the 9 meters setting so the image is dim when you are far and gets colorful as you approach which is somehow expected in underwater video.

The section at 15 meters are particularly interesting

You can see that URPRO gets better with depth but also how at 5:46 you see a fairly dim reef at 5:52 I switch on the lights and the difference is apparent.

At 6:20 the approach with Keldan was directly with the lights the footage still gives an idea of depth however the colours are there and the background water looks really blu as I had white balance set for 9 meters.

Key Takeaways

All filters produced acceptable results however I would not recommend URPRO for the Panasonic GH5 and settle for the Magic Filter or the Spectrum filter. Today the spectrum is the only wet filter for the Nauticam WWL-1 but I am waiting for some prototypes from Peter Rowlands for the magic. I would recommend both the magic and the spectrum and the choice really depends on preference. If you want a ready look with the least retouching the magic filter is definitely the way to go as it produces excellent ready to use clips that look good immediately in the LCD.

The Keldan Spectrum filter has a more desaturated look and requires more work in post but has the benefit of a more accurate image.

I think this experiment has proved to work and I will use this method again in the future. This method is also potentially available using the keldan or other ambient light using a tone that closely matches the lens filter.

 

Filter Poll

The importance of Underwater white balance with the Panasonic gh5

One of the key steps in order to get the best underwater colours in your video is to perform a custom white balance.

This is true on land and on water because auto white balance only works in a specified range of color temperatures.

Panasonic GH5 advanced user manual

For our GH5 the range where auto works goes is approximately 3200-7500K. When the camera is working outside this range you get a colour cast. Let’s see with some examples:

Grey card Auto White Balance 8mm
Grey card Custom White Balance 8mm

In the example above I am taking a picture of a white balance reference card under warm lights that have a colour temperature of 2700K.

As you can see the auto white balance fails resulting in a yellowish tinge, while the shots taken after the custom white balance is accurate.

In terms of white balance card I use the Whibal G7 Studio 3.5″x6″ (8.9×15.2 cm). I found this card to work well underwater and I use it with a lanyard attached to a clip that I hook on my BCD D rings.

More info on the whibal here

It is possible to buy a larger card such as the reference that is 7.5″x10″ however this is cumbersome and I found the Studio version to work well with the Panasonic GH5 as it only uses the central part of the frame for white balance.

Custom white balance with the 8mm fisheye

Going back to our GH5 instruction manual you can also see that the camera white balance is limited to 10,000K which is the colour of blue sky.

Underwater due to light absorption at longer wavelengths red and orange disappear at depth and blue tends to scatter over suspended particles. So the colour temperature of water tends to be higher than 10,000K and also the blue is somewhat washed out by scattering.

This is the reason filters are essential because reduce the amount of blue or to say better cyan and bring the camera into a range where custom white balance works again.

I have already posted a whole range of observations on filters in a previous post so am not repeating here.

With the right filter for the water colour I dive in and with the appropriate white balance card you can get some pretty decent results with custom white balance.

To help the colour accuracy I have experimented with the Leeming Luts and I want to thank Paul Leeming for answering my obscure questions. Obviously you do not have to use the LUTs and you can design them yourself however I found that using the Cinelike D LUT I have a very good starting point for colour correction.

The starting point is a CineLike D profile with saturation, noise reduction and sharpness set to -5 all other settings to default as suggested by Paul, there is no need to lower the contrast as CineLike D is already a flat curve.

*Noise and sharpness have actually nothing to do with grading but are set to -5 as the GH5 applies sharpening and noise reduction even at -5 setting. Sharpening has generally a negative effect all around while noise reduction if required is better performed in the editor.

Looking at imaging resource tests of the GH5 we can appreciate that the camera colours are oversaturated by default.

the GH5 has around 113% over saturated colours

The GH5 tends to push deep colour and wash out cyan and yellow. This becomes apparent when we look at a white balanced clip uncorrected.

White balanced clip in final cut pro you can see how the water column is washed out whilst red and other dark colours are accurate

The Leeming Lut helps rebalancing the camera distorted colours and when you apply the camera LUT, provided you have followed the exposure instructions and applied the profile as described, the improvement is immediate.

The previous clip now with the CineLike D Leeming LUT applied

From here onwards it is possible to perform a better grading and work to improve the footage further.

For the whole read please look at Leeming Lut website

One other thing that I believe it is interesting is that while generally for ambient light or balanced light shots I do not actually trust the camera exposure and go -1/3 to -2/3 for close up shots exposing to the right greatly helps highlights recovery

In the two frames you can see the difference the LUT brings restoring the correct balance to the head of the turtle.

Turte detail the highlights appear blown out
Turtle detail with Leeming Lut applied

To be clear the turtle detail has been white balanced in water on the whibal card while using a Keldan Spectrum filter -2, then in fcpx automatic balancing is applied. The LUT brings out a better dynamic range from the same frames.

Obviously you are free to avoid lens filters and LUTs and to some extent it is possible to get similar results however the quality I obtain using automatic settings I believe is quite impressive.

I found myself most times correcting my own wrong exposures or wanting to increase contrast in scene where I had little however this only happens in sever circumstances where white balance and filters are at the limits.

Conclusion

There are many paths to get the right colours for your GH5 underwater videos in my opinion there are four essential ingredients to make your life easier and give your footage a jump start:

  • Take a custom white balance using a professional grade white balance card
  • Set the right picture profile and exposure when shooting
  • (Recommended) Use appropriate filters for the water conditions
  • Apply the appropriate LUT to eliminate the errors in the GH5 colour rendering in post processing

With the following settings producing a video like this is very simple and all your efforts are in the actual cutting of the clip.

Short clip that applies this blog tips

Please note some of the scenes that look off are shot beyond the working conditions of filters and white balance at around 25 meters…

Getting the best colors in your underwater video with the panasonic gh5

There is no doubt that the Panasonic GH5 is a very capable camera and in given conditions the video performance you can get is truly impressive.

Broadly speaking a video clip needs to be:

  1. Sharp
  2. Colorful
  3. Contrasty
  4. Clean

Those 4 characteristics are tightly related to:

  1. Resolution
  2. Color depth
  3. Dynamic range
  4. Low Noise

Resolution

Today everyone shoots 4K and after all resolution is well supported by almost any camera, broadly is unaffected by other factors and unless the noise is really high sharpness of your frame is not going to be a real issue shooting at 4K.

Color depth

In normal conditions and not underwater a camera can resolve many colors. However underwater due to the diffraction of light and selective absorption of colours the starting point is very different from land. So generally is not the camera that cannot resolve the colors but the colors that are missing to start with. This post will focus specifically on this aspect. The Panasonic GH5 can resolve 23.8 bits in RAW and therefore technically has less than 8 bits color depth – do not confuse this with the 8 or 10 bit recording setting.

Dynamic Range

Underwater scenes tend to have limited dynamic range, with the exception of sunbursts or shooting against the light this is going to be an issue only in specific circumstances of very bright scenes with shadows. In all scenes taken with video lights dynamic range is not an issue at all. The GH5 has 13 stops of dynamic range but rarely this is an important consideration.

Noise

Noise is an important consideration as when the noise goes up the camera looses the other characteristics, color, dynamic range and resolution will be affected when the camera is outside the sweet spot. Broadly speaking the Panasonic GH5 does not do well once you pass the ISO 1600 setting and I tend to cap the ISO in video at 800 in most cases.

Diving Conditions

To understand how those variables play we can see how the same set up reacts very differently in scene where there is less light and therefore the camera uses high ISO like this one.

The same camera with exactly the same equipment in brighter water produces this

So the reason for the above is that with less light there are less colours and the clip looks what it is really.

OK moving on to the main subject of this post how do I get the colors right? It is a combination of techniques and the trick is to use the right one in the right conditions.

Generally every site has specific conditions that change depending on weather, time of the day, visibility and other factors. So in broad terms a site will have more or less light and therefore more or less colours. It is therefore impossible to categorically define what to do at a given depth but is more about typical values. With this in mind we have typically 3 scenarios:

  1. Ambient light shots
  2. Artificial light shots
  3. Balanced light shots

Close up Shots

In general close up shots especially of small subject fall within the scenario 2 for which a video light with high color rendering is important as this will define the colours you see. With a lot of power it is possible to extend artificial lighting to larger subjects but eventually you run out of power due to distance or size of the subject.

Wide angle shots and seascapes

True wide angle shots are generally ambient light shots which also means when it gets too dark the colors will be missing and it will look blue not matter the equipment.

In order to make the most of ambient light shots for wide angle it is essential to balance the colours in water even when you use a RAW format on a still image because RAW files are not as RAW as you think and are actually compressed.

Custom White Balance

Using Custom White balance with a grey card it is possible to obtain decent results until the camera hits the maximum color temperature in the case of the Panasonic GH5 this is 9900K. Depending on conditions you may get to 10-12 meters and this still works, in darker water this stops working much sooner.

Chrisoula K Bow
Chrisoula K Ambient Light 5 meters

Color Filters

Color filters push the limit of custom white balance further down. Some add more or less 4 meters others up to 6-8 meters at the expense of an overall loss of light. Filters are useful when there is a lot of light because also help to keep the Panasonic Gh5 in the best aperture range (not smaller than f/11)

Filter in action at 10 meters

Right now there are predominantly 3 filters on the market:

  1. UR PRO
  2. Magic filter
  3. Keldan Spectrum

All those filters will improve the performance and color rendering of your footage, under the conditions that the loss of light is not pushing the camera above reasonable ISO values.

In terms of depth range the magic filter and the Keldan Spectrum -2 version can be pushed to 15 meters depth on a bright day in clear water. The URPRO is capable of getting a few meters more down to around 17-18 meters although it does generate an orange cast (as there is no red left) it is still workable.

FilterLight LossTypical Max Depth
Magic Filter1 2/3 Ev15 meters
Keldan Spectrum -22 stop (WWL)15 meters
URPRO 1 2/3 Ev18 meters

This image gives an idea of the 3 filters as you can see they are very different one from the other.

Keldan top URPRO bottom Magic filter

Balanced Wide Angle Shots

This is an entirely new technique that has started with the Keldan Ambient light filters. I wrote a whole piece on wetpixel

The principle is to use custom white balance with or without filter to obtain color rendering and then put filters on the video light so that the color of the light emulates the ambient light and therefore it only gives texture not color.

Keldan has developed a whole range of filters for various situation that match their light and therefore are not applicable to any other light.

As I do not own a set of Keldan I have done some tests and found that a gel of Cyan filter 2 or 3 stops makes my divepro G18+ practically ambient light in the conditions I dive into.

FilterCyan Strength
Magic Filter2 stops
Keldan Spectrum2 stops
URPRO3 stops

The above value are based on my experience use at your own risk especially with different lights.

Square Cyan 2 stops Round Cyan 3 stops

To give an idea I overlapped the filter to my iPhone lens

This is the shot without any filters

Original Shot

URPRO and Cyan 3 stops (darker)
Magic filter and cyan 2 stops accurate
Keldan and cyan 2 stops accurate

This example shows that the two filters cancel themselves the result is almost daylight with no cast which means in water if you use a video light or a strobe you will not see a red or orange spots on the image.

For those taking pictures the same combination remains true with Inon Z240 and Sea and Sea YS-D2

Example picture here

five in a row
My own filter and Cyan 3 stop note that the light is coming from the other side

One thing to take into account is that you need to find a way to hold the gel on the video light or the strobes. The flat surface strobe diffusers make this process easy, finding something you can use with your video lights is not easy and also the gels may melt after continuous use.

Artificial lights

It comes a point and a depth where filters stop working, this could be as shallow as 8 meters in green water. As the scene is dark using lights is what is required. There is nothing specific about this technique except making sure you don’t get burned highlights or backscatter. As it happens in photography using long arms (maybe not as long as for stills) is key to get good lighting on your subject.

My Camera Settings

I use CineLike D with saturation, sharpness and noise reduction to -5. I shoot at 24/25p AVCI 400 mbps and follow the 180 rules, it is entirely possible to shoot at 1/100 if you like more crisp look.

Clearly there are people out there that do not like filters and think white balance is best etc but I think a good read on magic filters explains it all.

http://www.magic-filters.com/need.html

Getting the best underwater colours for your 4K Sony RX100 Mark IV

It is not a mystery that even the new Mark IV version has issues with custom white balance.

The ergonomics have not changed and you need to go into photo mode to set custom white balance but generally underwater results are poor. Using filters is therefore a necessity also on the new 4K version.

RX100 Mark IV Video Behavior

The RX100 offers now a 4K 100 mbps mode and can use picture profiles.

I have used a modified version of PP6 that use the cine2 gamma curve, I have however changed the colour to the Pro mode and changed a number of other settings in my last video in Puerto Galera.

The water was green and murky but this gives you an idea of what you can get.

Filter Options and Wide Angle

Although the Nauticam WWL-1 is the best lens for the RX100 it does not take filters and therefore is not adequate for video.

In this review clip you can see the options available on the market.

In terms of wide angle you have two options for 4K:

  1. Inon UWL-H100
  2. Inon UWL-100

Both lenses work fine in 4K however the older UWL-100 achromat does vignette in photo mode.

The UWL-H100 offers a very wide field of view also in HD mode with no vignette and accepts the mangrove/deeproof filter.

This filters is loaded with magenta so I suggest adjusting the tint in the auto white balance mode to +2 green.

The UWL-100 works fine in 4K and is wider than the UWL-H100 however has only the M67 mount. If you have one of those lenses you can use the Ikelite 6442 filter. This filter required you to remove the rubber ring on the lens and does work quite well except has a yellow cast to it you can reduce by changing the tint to +2 blue and increasing also magenta to +1.

For flexibility purposes probably the UWL-H100 is better as it takes the bayonet but the UWL-100 is really wide and has a little less fringing. Some people do like the UR/PRO filters better.

I hope you find this post useful and good luck with getting the best colours from your Sony RX100 Mark IV

Panasonic GX7 First Test

So time has come for my first video with a micro four third camera the Panasonic GX7. I had only 3 dives in Sharm and conditions on Naama Bay beach were not the best but still good enough to give the set up a good try, this is the resulting video.

I used the Nauticam housing with the Macro 35 port and the M67-LD adapter so that I could use the Inon UWL-H100 wet lens.

As it is not possible to fix the position of the lens I had to take the hood off and therefore I used an Ikelite UR/PRO filter for the 100mm lens. I had to use gaffer tape on the lens and inside the filter or it would be loose but it worked.

The first dive was with the URPRO filter in auto white balance, I was hoping this would give me good results but instead everything came with a strong yellow cast.

From the second dive I used custom white balance and the results were much much better.

To give an idea of the issue this is a shot of a grey card with the UR/PRO filter on land with white balance fixed.

URPRO test card
URPRO test card

You can see what kind of effect the filter bear it is orange in colour.

Other than this I was pretty happy with the GX7 especially because I could use the full zoom with the wide angle lens this is the first time I see it working. The moray eel shot towards the end of the video is an example.

Back home I was not happy at all about the UR/PRO and the inability to work with auto white balance. Probably I could have played with the tint but it did not come to mind. So I got in touch with Peter Rowlands of Magic Filters to see if they had an option that would fit on the Ikelite mount. Peter sent me two sample and they fit perfectly in the ikelite frame, though this is not commercially available I guess you can request those if you are not happy with the ikelite UR/PRO.

This is the same test card with the magic auto filter.

DSC04030

You can see that it looks less orange and also slightly colder.

I did some tests and the UR/PRO is a warmer filter with 2700K temperature whilst the magic auto is 3200K. The magic is however more red and has more magenta tint than the UR/PRO.

For me this means that the magic will work better in auto and will require less custom white balance. However those 500K difference mean you will eventually need to custom white balance once you go below 18-21 meters. I know people say filter work until 21 meters anyway but I have tried with deeproof down to 30 and on a bright day it was still good.

So if you are not happy with the yellow cast of your UR/PRO in auto white balance is definitely worth giving magic filters a go.

The GX7 confirmed all the good features including the ex tele mode

Here the shrimps are shot with a single Inon UCL-165 and then the close up of the head uses ex tele that pushes well over super macro.

Look at the incredible ability to refocus in video mode. See how focus locks on the shrimps when I press the button.

Overall the GX7 can do pretty much everything on a single dive with a wet wide angle lens and a close up lens. You can cover from 100 degrees wide to super macro. The fact you can zoom with the wide angle removes the need to take the lens off at every occasion and in fact in the red sea you barely need to have any other lens.

I was not particularly happy with the lack of hood that the ikelite filter wants removed so I experienced the occasional flare. Still pretty good result.

The clip looks much better at home than it does on youtube where the gap with the RX100 seems much smaller.

So as far as video is concerned if you don’t need 4K the GX7 gives you extremely high quality footage and reasonable cost.

A final note I shot this video in 24p at home I can’t tell the difference with 25p see if you can see it!

Video Feature Sony RX100 Mark II in Malta

Following from my previous post I managed to get together a clip out of the 5 dives I did

The first day was somewhat plagued by visibility a bit lower than the norm for the location but the second day was fabulous

For this trip I brought with me the Inon UWL-H100 and the red push on filter from deep roof H20 and the Inon UCL-330 as I was expecting medium size fish and nothing really small

Here is the outcome

I am quite happy how things turned out so let me share the settings with you

First I shot most of the footage in 25p AVCHD mode only some small sections are shot at 50p and actually I did not need to slow down any of the material.

For the wide shots I used steady shot in normal mode and shutter priority at 1/50th. With the filter on I had auto white balance with tint correction G2 A1. I noticed that the camera was giving red tint in some situation and so added a bit of green back. The Amber correction instead is for the RX100 itself the camera does not have vibrant yellow and is a bit blue.

Tunas
Tunas – AWB with filter

For the first time I use creative mode changing the standard contrast to -3 in order to prevent crushing of blacks.

Exposure was set all along to -1/3 and metering to multi area with AUTO ISO limited 160-800.

I think the results are so good that in fact I have performed no colour correction to any shots in ambient light.

Opening the tuna farm
Opening the tuna farm – AWB with filter

For shots with lights I set up first colour temperature to 6500K and A1 to match the lights but then in some of the far shots this resulted a bit cold so I adjusted very slightly in post the temperature.

Seahorse
Seahorse – AWB UCL330

Only 40″ are adjusted in the whole video in essence is as shot and the editing took me half hour.

In cave
In cave –  AWB no filter

I did a bit of analysis and the camera was operating for most at ISO200 with aperture around f/3.5 – f/4.0 which is really the sweet spot of the lens.

I did have some challenges using the UCL330 for some nudibranches  that really required a stronger lens so they look a bit small, there was also surge so I had to fight with focus problems but all in all very happy.

Nudibranch
Nudibranch – AWB UCL330

The longer working distance of the UCL330 (20-30 cm or 8″ to 1′) proved challenging on walls as you are too far to hang on to anything or use a stick. I will bear this in mind in the future.

For the close up shots I used steady shot active.

I also wanted to say that a few times the camera did manage to white balance properly however the results were not exciting and frankly not worth the hassle. Using the filter is just so much better with the auto white balance.

Introducing the Sales Corner

I receive so many queries about equipment that I thought I would put some of my items on sale.

My cupboard is near enough to explode and I need to streamline the equipment I have. Currently I have 3 strobes, a huge selection of ball and clamp arms, 3/4 and 1/2 locline arms, float arms, floats, video lights, tray bases, around 15 clamps and some 6 macro wet lenses and 3 wide angle wet lenses with 3 different mounts.

I guess it is time for a clear up so I will add a section with items on sale where I will list some of the combination items.

The idea is to provide a full set of lenses or a tray + float solution as those seem to be the most asked for items in my set up.

So if you look on the menu you will see the link Sales items with details of the various sets. I can also sell the items individually but I think this makes little sense as I’d rather do that on ebay.

Many people read my posts and then go to gear shops but there there is always a little mistake or problem getting the whole set up from here you avoid that. I priced the items based on 50% of retail UK price and I would ship to UK and Europe, other overseas will attract import duty so it is not worth it in my opinion.

If there is anything you like  use the contact form on the relative page to inquiry

Sony RX100 Mark III – Is it worth upgrading?

UPDATED 23 July 2014

Once again Sony has updated their RX100 camera with a stunning new release that will surely be a market leader at least until the release of the new promised Panasonic large compact sensor with 4K video recording.

So the question is again is it worth throwing our hard-earned money to this new model and housing or should we stay with what we have got? The Mark I and II are still available at reduced price though it is becoming harder to find Mark I housing as new.

The answer to the question is: it depends on what you are planning to do with your RX100, for some users an upgrade may not be required or even not advised let’s see why. no don’t waste any time with the Mark III.

Every time a new camera is released and reviewed I get a bunch of emails with subject: New Camera XYZ what do you think?

The best reviews you find online are made by sites that specialize in land photography and no consideration is given to underwater use. So not necessarily a camera that is a top performer on land will remain such underwater as this depends on specific characteristics that may be different or even opposite to land requirements.

So those reviews cannot be taken as they are they need interpretation. Personally I use two sites for camera reviews imaging resource and dxo mark I use the first to understand ergonomics, performance and to compare images with other cameras side to side, and the second to check sensor quality and lenses. Imaging resource has made a good article to compare the various RX100 on land read it here

http://www.imaging-resource.com/news/2014/06/16/battle-of-the-rx100s-sonys-rx100-vs-rx100-ii-vs-rx100-iii

If you look at a sensor comparison on DXOMark you would conclude that there is no need to upgrade at all if you use your camera primarily for still pictures as the sensor are practically identical in performance as this table demonstrates:

RX100 Sensor Ratings
RX100 Sensor Ratings

As you can see the differences in dynamic range, color depth or ISO are pretty much intangible.

However there are other metrics that are also important let’s see which ones and why.

Flash Recycling

We want our camera on board flash to recycle quickly after a full dump as the RX100 has only TTL flash and the flash can’t set to a minimum manual setting without consequences. Those are the flash recycling times at full output (a full dump will always occur when you don’t aim strobes directly at the subject for example wide angle)

Mark I: 7.2 seconds

Mark II” 4.4 seconds

Mark III: 3.3 seconds

The Mark III is pretty quick and the Mark II is acceptable the first release is definitely too slow.

Minimum Capture Area & Zoom

What is the smallest area that can be captured at wide end at the closest focus distance? This gives you an idea of out of the box close up performance

I do not have precise metrics yet but looking at comparable images on imaging-resource seems like the Mark III is worse than the Mark I and II of at least 20% with a capture width around 90mm versus the already not very good 76mm of the Mark I and II.

To fix this issue we use close up lenses in water that fix to a great extent the focal length and then zoom in to achieve magnification which means longer camera lens more magnification I roughly estimate that the Mark III will be worse of a factor of 0.7x so things will look 1.4x bigger with the Mark III this is terrible news for macro shooters as it means you need to be on top of the subject to fill the frame, this is in some cases not possible.

I have estimated that you need 11 diopters to achieve 1:1 macro so the Subsee 10 and Inon UCL100 that gave real macro on the Mark I and II won’t be sufficient. With two UCL-165 or Dyron 7 you are looking at 2.58″ or 6.5 cm from the back of the first close up lens that means you will be right on top of the subject which is not really an option.

Update July 18th: Nauticam has confirmed that even with their SMC lens the most powerful diopter on the market the capture area is 38mm wide so does NOT achieve 1:1 macro as I suggested…

 

Lens Focal Range

The new mark III has a 24-70mm lens compared to the 28-100mm of the Mark I and II what does this mean?

  • Less magnification with close up lenses and no real 1:1 macro
  • Vignetting or even not possible to use fisheye lenses designed for 28mm lenses

This means that with the Mark III your scene selection will be restricted  compared to the 150 to 24 of the mark I and II.

Update 23 July I have done some tests that confirm my suspicions please look at the following frames. The Mark III once zoom to 28mm actually works fine with the Mark II housing except the power button.

RX100 Mark III with Inon UCL-165 Close up lens
RX100 Mark III with Inon UCL-165 Close up lens

With a single Inon UCL-165 (+6.06 in water) the minimum capture area width is 5.4 cm which is bigger than the Mark II 4.8 cm. Not only that the distance from the top of the lens is only 9cm.

With stacked UCL-165+UCL330 total power 9.09 diopter we get this

Stacked UCL-165+UCL330
Stacked UCL-165+UCL330

4.4 cm width however we start running into problems as the minimum distance from the lens is only 4cm.

We finally achieve 1:1 with two stacked UCL-165 however the distance from the top of the lens is 3cm definitely too little

two UCL-165 stacked
two UCL-165 stacked

I have also tried the Mark III at 28mm and it still vignettes with the Inon UWL-H100 in air until around 30mm. Instead the old UWL-100 28AD is fine at 28mm either way image looks narrower than with the Mark II but this may be an issue with the old housing.

So basically no macro with the Mark III and no decent fisheye as expected.

Underwater Photography Conclusion

Due to the reasons above the best camera for the job is the RX100 Mark II, with the Mark I coming close but being penalized by the strobe recycle time, the Mark III really is not an option for the serious shooter due to limitations of the lens.

Let’s have a look at some other features of the Mark III that are not relevant for stills as much as they are for video.

ND filter

Shooting at the surface with plenty of ambient light or on land can create problems if you want to follow the 180 shutter rule, the ND filter of the Mark III ensures your footage will be smooth on land and in water. Take into account that on land you can apply optical ND filters (I have it for the Mark II) so this is really for underwater use when you are shooting at 1/50 or 1/60 shutter speed and the scene is too bright when you hit f/11 and the lowest possible ISO. Having now tested this feature I confirm it is really valid on land on a bright day to keep the aperture wide.

Clear Image Zoom

This is a special digital zoom with edge enhancement that only worked on JPEG stills on Mark I and II but is now available on video on the mark III. This means an additional 2x zoom is available bringing the focal length to 140mm that is more than adequate for macro. This is not an option on RAW images so irrelevant for still users.

23 July update Having done some tests for macro video (as stacking two diopters is not an option) the image quality suffers but anyway this is all you are left with lacking any other options.

Clear image zoom 1.5x on single UCL-165
Clear image zoom 1.5x on single UCL-165

Image stabilizer

The Mark III adds a further stabilizer mode with additional crop that takes the lens to 96mm equivalent in video mode. This is well worth for super macro hand-held footage and effectively provides an option where you can either use the super steady shot and no clear image zoom when hand-held or leave on only the optical stabilizer and use clear image zoom. If you shoot macro on walls and not on flat sand this is a well worth feature.

Update 23 July 2014

Following a side by side comparison you can find on this link

It follows that there is really no 5 axis stabilisation and only an additional mode with more crop with correction for rolling shutter that anyway does not really work!

Full Sensor Readout Video

The mark III reads the whole sensor not just alternate lines when capturing video this increases should increase the resolution to a great degree and increases the perceived resolution and clarity of your videos. However this does not seem to correspond to real life tests. See this sample with a side by side comparison the Mark III looks visibly worse than its predecessor even on the higher bitrate XAVC!!!

Video Formats

The Mark II introduced a well welcomes 24 Mbps 24/25 fps mode now the Mark III introduces a 50 Mbps mode in XAVC (that can be rewrapped into normal MP4) that produces even better footage although it will be quite demanding on your workstation and most likely some of your home devices will struggle playing the files (my Apple Tv 3rd generation only plays up to 25 Mbps) when uploading files online this will downgrade to 8 Mbps so won’t matter unless you have a good player at home. improves nothing and requires manipulation as the files are actually not MP4 compliant as they have WAV audio (!) they are also inside the AVCHD folder which is painful. As seen above seems like the encoding has got worse on the AVCHD files and only the higher bitrate compares but still does not match the mark II at the lower 24 Mbps!!!

HDMI connection

You can now connect the Mark III to an external HDMI recorder if you are into that kind of semi pro usage. For the normal user this is not relevant: if you are into spending that money probably you have already a DSLR or a Panasonic GH4.

Video Auto Focus

The auto focus in video has got worse you can see an example in the stabiliser test, and actually plenty of frames are blurred on the mark III. Awful!

Underwater Video Conclusion

The Mark I with only a 28 Mbps 50/60p mode is definitely a poor choice, the Mark II is acceptable to most users. and the mark III promises even better performance if you are a serious video user and have another camera to take pictures the Mark III may be well worth it.

The Mark III despite some useful feature is actually a let down and perform worse in practical terms than the mark II that remains my camera of choice.

Summary

If you have a Mark I camera and are frustrated with flash recycling you should be looking at a cheaper upgrade to the Mark II.

If you have a Mark II and your priority is photography upgrading is NOT recommended.

If you don’t have any RX100 get yourself a Mark II or wait for the new Panasonic as the Mark III is pretty much a pile of crap.

Is it the first time I am actually sending back a camera and invoking consumer rights but when I spoke to the camera shop they told me they had other returns and this is not really an upgrade!!!

Look Right inThe above image was shot at 100mm equivalent with one diopter with the RX100 Mark II. You won’t be able to fill the frame with the same close up lens and the Mark III camera

Sony RX100 White Balance Woes

In one of my first posts on this blog I covered the subject of setting white balance with the Sony RX100.

It may be useful to have a quick recap on the topic:

  • For pictures setting a custom white balance is not useful if you shoot in RAW as the amount of correction in post processing is far superior*
  • For video (that is shot in compressed format) setting the appropriate white balance for your shots is essential

There are exceptions to this rule, some people like to set custom white balance even in RAW when they shoot ambient light pictures. This is because changing the white balance shifts the histogram and therefore if you had taken a shot with an incorrect white balance you may retrieve wrong information from the histogram. Personally I do not do this most of the ambient light shots I judge by eye and not histogram or are silhouettes anyway but may be useful to know.

The other exception is when you shoot a raw video format with bit rates in excess of 100 Mbps, in that case the footage is captured in a bland format lacking any real depth and contrast and things are corrected in post processing. This does not apply to any consumer camera that works in AVCHD or Mp4 with bit rate lower than 50 Mbps in any case.

It follows that setting the appropriate white balance for our videos is something that is important otherwise our clips will look dull, green or have some sort of color cast we do not like.

As many of you RX100 I have experience with the infamous Custom White Balance 9900K error. In theory if you set your custom white balance with the camera in P mode over a neutral target this error should only occur if the color temperature is out of range (>9900K) unfortunately this is not the case and you get this error pretty much always with our beloved camera. At the beginning I thought that this was due to my cheap PADI slate, but after various attempts against my hand, sand, buddy’s tank, the sun I have to think there is some genuine issue here.

So I got myself whibal card, that on my test on land performs amazingly well with both the RX100 and the Nikon D7100.

The first thing we can realize is that the auto white balance setting is rather cool in outdoor scenes, whilst it tends to be warmer in indoor scenes with artificial light.

Auto White Balance
Auto White Balance

When you take a custom white balance the colors appear warmer and the bluish cast departs and the yellows come back.

DSC01608

This is particularly bad news if you shoot underwater without a filter and think of using auto white balance as those results will be pretty ugly.

The whibal card has a specific black mark that if illuminated tells you the white balance reading is incorrect because of reflections. I thought this was the key to the 9900 Error, unfortunately I was wrong.

It just fails 100% reliably really painful so I could not get rid of my trusted red filter for the Galapagos trip. I even tried setting the white balance with the filter and it would fail as well.

So I went back to auto white balance and red filter and I am pretty happy with the results, many people have asked me if I have manipulated the footage in post processing as the colors look very deep and some have even said unnatural. Even so shooting at 1/50 means a relatively low ISO and in the specific trip another f/stop of aperture was not really significant but I would have like to have the option of working without the filter, sadly this was not an option.

For what concerns white balance just a few things I want to say:

1. At depth there is no color anyway so what your eye can see it is not what it is, the proof is when you use lights or strobes things look much better than the naked eye. Using your visual as a reference can produce dull results.

2. You have to set an appropriate white balance for your scene, this means removing the cast. If a scene has no cast and the colors look saturated this is not a white balance issue on its own but may due to the camera settings. The RX100II is one of the less saturated camera on the market. The mark I instead is pretty saturated take this into account.

3. Footage that looks dull IS in fact ugly. The fact you set custom white balance with or without a filter does not mean that results is the perfect result, there is no such thing in fact and as colors disappear at depth white balance is not that effective anyway

Nick Hope sometime ago published some interesting tests on wetpixel

http://wetpixel.com/forums/index.php?showtopic=16970&page=8#entry122288

It turns out that there is more than meets the eye.

Just to clarify the only color correction in my Galapagos clip is:

1. In the scene of the dolphins I was pointing the camera upwards and did not have time to take the filter off so ended up with a red cast, I performed a white balance adjustment in iMovie on the opposite value of the tint I was getting until I liked it.

2. In the scene where there is a group of Galapagos sharks and the close up of the eagle ray I have reduced the blue gain as it was over saturated

In all other cases the only changes were increase of contrast or reduction of brightness. When the water was green like at the end in the Punta Vicente Roca scene I did not touch it to make it look artificially blue.

Again for those who ask I use a deeproof push on filter for the Inon UWL-H100 this filter is my preferred for the only reason that is actually the only one available on the market that fits on the lens. Personally I would much prefer a plastic filter like the ikelite/URPRO but this one is glass. It seems to correspond to a deep sunset 2700K with magenta tint of +5 on the RX100 but I have no tools to measure it I can only say it works.

So my recommendation for the RX100 is to get this solution as the Inon lens has the best optical quality and a hood that comes very handy to reduce flare. There are other lenses that fit the RX100 but have no hood. Obviously an not even considering the fisheye style lenses as distortion is ugly and placing a filter under the lens is a very bad idea.

Galapagos: Sony RX100 Mark II Video

The time finally came for our trip to Galapagos and I was ready with a set of think rubber suits to overcome the cold water. I just bought a 5mm Oneill Sector (wonderful suit) a 3mm hooded vest, kevlar gloves and a 5mm 4th Element short john. Well the short john was not used and for most I used just the wetsuit and a set of O’Neill Thermo X unders (very recommended) as El Nino is coming and the water was warmer at 25-27C or 77-80F.

This means lack of schooling hammerhead at shallow depth close to the reef, they were in the blue. We had however our good dose of schooling barracuda, tuna (in the 1000s) and even galapagos sharks

This is the video I produced

If you have problems with playing in your country use vimeo instead

The conditions were difficult with low visibility and in some sites very green water as you can see here

Green waterQuestions will come about what I used etc etc so here is the list

  • Sony RX100II in Nauticam housing
  • FIx adapter for Inon LD mount
  • Inon UWL-H100
  • Deeproof blue water filter
  • Sola video lights 1200 (just few shots of the barracudas and some close ups)
  • Combination of arms and sometimes no arms
  • Ultralight tray TR-DM with extension and handles

The video has been produced with iMovie 9.0.4 no stabilization performed except the scene with the moray eels mating (very mild)

I shot the whole trip in shutter priority 1/50th of a second in the 25 fps 24 Mbps format. After some tests at home I have decided to use this mode as I can’t physically play the 50 fps files the camera produces on any of my devices differently. The 25 fps gives a film look and very smooth footage. This format is only available on the RX100II and not on the original RX100 so the consideration I made at the time for video settings of the RX100 remain valid.

The benefit of 1/50th shutter speed is a full f/stop of light the disbenefit is that at the surface and for backlit shots this is too slow, in those cases I go back to program mode or increase shutter speed to 1/100 or 1/200 or more.

For what concerns the editing I import the raw files in iMovie without using the conversion and then export with x264 using very slow preset and level 4.0 compatibility to use it with my appleTv.

I do minimal color correction in some cases I had to eliminate the red color cast of the filter when shooting upwards, to do that I change the white balance to top yellow until i remove the cast.

In some cases I had to put the green gain to the max for the same problem but in all other cases there is NO color correction in post.

When you work with AVCHD cameras the footage is compressed and the key is to get it right in camera.

As Galapagos conditions were challenging, although less than I expected, I used gloves in some dives to hang on to the barnacles and I also modified the set up to completely eliminate the lights.

I would dive with two 3″ segments and two 6″ Inon Mega float arms when I had the lights on and for other shots in ambient light I would have this set up here that looks odd but it is very effective and almost neutral at only 120 grams in water. The position of the floats means the camera stays upright at all times.

Compact tray for ambient light
Compact tray for ambient light

I would put a single Sola light on top of the housing not for video purpose but to signal the dive master when I was a bit far in the murky or dark waters. I used this set up on almost all blue water dives (Darwin and Wolf) and the normal set up with lights for the South and West sites with murky or green water.
There will be a separate post on the photos, I did a total of 18 dives with the camera of which 4 where photo and 14 video. You can see an example in the featured image.

I have now ran some statistics on the final clip that I produced

I used a total of 41 video clips:

ISO average was 273 with the following breakdown

  • 2 clips at 160
  • 30 clips at 200
  • 6 clips at 400
  • 3 clips at 800

f/stop average was 3.1 hyperfocal distance on average 1.16 meters. So if I were able to shoot without filter I would have not gained anything in terms of sharpness as most subjects were further away

I would consider the Galapagos and the dive trip I did not the best in terms of brightness and visibility so I would conclude that the RX100II with the Inon UWL-H100 and a red filter is the best set up for wide angle video in terms of performance, ease of use and flexibility.