Yes, the pictures I'd posted are also from their product page, but I don't understand how it's possible unless they moved the lens further away from the supersuit port.
It's snug on the original AOI, no room for a piece of plastic as far as i can see, as the back of the lens sits almost touching the supersuit port.

Moving it forward seems risky (increasing the risk of vignetting and corner deformation), so not sure how this works. This thread mentioned vignetting with the mount, but then none if cropped to 16/9, so not sure...
 

 

Edited June 23, 20241 yr by bghazzal

 

Yes, AFAIR the lens is moved away a bit and there's small aperture on the side.

On this video is clearly visible on the instructions and the mount itself.

I wonder if the original AOI mount works with the full resolutions/ aspect ratio of the latest gopros: 5K and 8:7 while the Backscatter mod doesn't work as per several feedbacks.

 

 

 

 

9 hours ago, bghazzal said:

 

Yes, that’s exactly it - clearly the same issue, and as you pinpointed it, it's clearly a weaker filtering of the greenish cast in the ambient spectrum...

This is actually also an issue I had why I tried the Keldan Spectrum on the GoPro – it was way too weak, even in Palau’s generally blue water.  And to add to this, the Keldan Spectrum gels are also slightly weaker than the SF2, as they’re sold as SF -1.5... 
 

Interestingly, they worked fine when manually white balancing the Lumix to ambient light at depth, the UR-Pro performing the worst of the 3 (Keldan SF-1.5 gel > Original Magic > Ur-Pro CY), and it’s exactly the opposite ranking on the GoPro (Ur-Pro CY > Original Magic  > Keldan SF-1.5 gel ), which clearly needs a more powerful filter.
 

All this highlights the importance of having a good filter to work with, as I was mentioning above – these 3 filters are well-designed specialist products, and yet they behave quite differently, which becomes even clearer when working on the footage in post...
 

While the Magic is useable, I’m also a little worried about the red/magenta/orange boost I saw a little deeper – I’m guessing it’s also an effect of the white balance being thrown further off by blues/greens, leading to overcompensation.
This is not good, as needs more work in post and this further degrades image quality…
 

Thanks for the links to gels, it would be great to try to reverse-engineer the UR-PRO SWCY formula – they really had something going with it, it's really a shame to lose such a tool.

 I have no idea how manufacturers work on designing custom filters – do you think the UR-PRO SWCY was actually a proprietary design (like the Keldans), or based on some pre-existent tone (which could then be source / purchased?).
 

Unfortunately, the Rosco/Lee gels are near impossible to source in Indonesia – there is a distributor in Singapore, but the sample I ordered didn’t make it over the first time, and with custom duties it’s a bit of a nightmare.
I think it’ll have to wait a few months, when I’ll be in a place where gels are not accessible...

cheers

 

 

 

I'm really not sure how the various manufacturers have developed their particular filter. For some, it may have been a combination of trial and error using various existing gels. Of course, you could also do it by measuring the target underwater ambient spectrum you want to 'normalize' to daylight -- so, if you have a spectrometer in an underwater housing, you could take it to say, 10m, measure the spectrum of the light there (of course it would vary form location to location and conditions) and then reverse engineer which wavelengths you need to filter out to neutralize the light and work out what sort of filter you need using math/physics 🙂

12 hours ago, Davide DB said:

I wonder if the original AOI mount works with the full resolutions/ aspect ratio of the latest gopros: 5K and 8:7 while the Backscatter mod doesn't work as per several feedbacks.

 

The AOI mount also vignettes in 8:7 but considerably less than the Backscatter mount.

 

cropped to 16:9 (or 9:16 for that matter) both mounting options work fine. So if filters are desired, I would definitely opt for the Backscatter mount.

Edited June 23, 20241 yr by Robin.snapshots

10 hours ago, DreiFish said:

 

I'm really not sure how the various manufacturers have developed their particular filter. For some, it may have been a combination of trial and error using various existing gels. Of course, you could also do it by measuring the target underwater ambient spectrum you want to 'normalize' to daylight -- so, if you have a spectrometer in an underwater housing, you could take it to say, 10m, measure the spectrum of the light there (of course it would vary form location to location and conditions) and then reverse engineer which wavelengths you need to filter out to neutralize the light and work out what sort of filter you need using math/physics 🙂

 

Hmmm, logisitics are a tad tricky, my spectrometer is still at the cleaners, all that 😁 😉

Looking at your tests for the ambient filters, I'm wondering if would it make sense to try shooting a still of a colour checker on land, first without, then with the UR-Pro and original Magic filters on.

With high CRI strobe and WB set to the strobe's, it should be close to neutral lighting on the raw file, right?
 

Then maybe the individual colour reading differences, especially blues and greens squares, could be measured in software (I'm really bad at image software, but I guess photoshop or lightroom can give such readouts?)

Wondering if this could be a quick and dirty way to get a rough curve highlighting the main differences between the two filters, and then seeing what best matches Rosco / Lee graphs in terms of required filtering range.

 

 

 

Edited June 24, 20241 yr by bghazzal

2 hours ago, Robin.snapshots said:

The AOI mount also vignettes in 8:7 but considerably less than the Backscatter mount.

 

cropped to 16:9 (or 9:16 for that matter) both mounting options work fine. So if filters are desired, I would definitely opt for the Backscatter mount.

Thanks - Backscatter's mount isn't sold in these parts, only the standard AOI, and importing isn't an option - but it could possibly be an option elsewhere.
 

The tricky bit, given the proprietary design, would then be to find a flat acrylic UR-PRO CY somewhere, and one large enough to work with.
Most of the ones still on sale are glass, and the acrylic ones I have are slightly convex (SRP's blurfix mount, with 55mm threads directly on the side of the filter)

Once the large acrylic UR-Pro filter is found, would then need to cut/machined it to fit in the Backscatter mount...

 

Other options I could see, that would require no machining and standard UR-Pro filters would be buying the AOI 55mm thread adapter.

 

- The mount would then be:

 

GoPro Supersuit > 55mm filter adapter > 55mm UR-Pro Filter > AOI 55mm thread adapter > AOI UWL-03 lens
 

But with the extra weight of the lens it probably wouldn't hold on my 55mm filter adapter, and if I ever upgrade the GoPro, the filter adapter is no longer available for more recent models (one of the reasons I didn't upgrade, as previously discussed)

 

A more stable option would be to get the more sturdy and universal  Inon 67mm filter mount for the supersuit -

 

There are no 67mm UR-Pro filters available, so the mount would then be:

 

GoPro Supersuit > Inon 67mm filter mount > 67mm to 55mm stepdown ring > 55mm UR-Pro filter > AOI 55mm thread adapter > AOI UWL-03 lens

But clunky as well, and what of vignetting with all those adapters...

 

Not easy, not easy...

 

 

Edited June 24, 20241 yr by bghazzal

12 hours ago, bghazzal said:

 

Hmmm, logisitics are a tad tricky, my spectrometer is still at the cleaners, all that 😁 😉

Looking at your tests for the ambient filters, I'm wondering if would it make sense to try shooting a still of a colour checker on land, first without, then with the UR-Pro and original Magic filters on.

With high CRI strobe and WB set to the strobe's, it should be close to neutral lighting on the raw file, right?
 

Then maybe the individual colour reading differences, especially blues and greens squares, could be measured in software (I'm really bad at image software, but I guess photoshop or lightroom can give such readouts?)

Wondering if this could be a quick and dirty way to get a rough curve highlighting the main differences between the two filters, and then seeing what best matches Rosco / Lee graphs in terms of required filtering range.

 

 

 

 

If you shoot the test chart illuminated primarily by a strobe with WB set to the strobe's 'native' temperature (which, actually, probably isn't the advertised temperature from the manufacturers), and with a red filter on the lens, what you're going to get is not a 'neutral' picture -- instead, you'll see exactly what filtration effect the on-lens filter has on the light spectrum produced by the on-lens filter.

 

You can then apply white balance in post to a white or grey square on the color checker and the resulting adjustments will give you an idea of what the filter is doing. So this approach is a valid one for comparing one filter to another and to see  which parts of the spectrum the filter attenuates.

19 hours ago, DreiFish said:

 

If you shoot the test chart illuminated primarily by a strobe with WB set to the strobe's 'native' temperature (which, actually, probably isn't the advertised temperature from the manufacturers), and with a red filter on the lens, what you're going to get is not a 'neutral' picture -- instead, you'll see exactly what filtration effect the on-lens filter has on the light spectrum produced by the on-lens filter.

 

You can then apply white balance in post to a white or grey square on the color checker and the resulting adjustments will give you an idea of what the filter is doing. So this approach is a valid one for comparing one filter to another and to see  which parts of the spectrum the filter attenuates.

Thanks - I'll try this with GoPro raw stills - I don't have a colour checker or a strobe but do have a calibrated Whibal grey card, and the Backscatter MW4300 video light is supposed to be calibrated to 6000K in wide mode (for pairing) - not sure if the is truly accurate (I do find it quite warm in post...), but it's the best I can do here, since I also don't have a light-meter.

 

I mentioned colour checker more for the colours themselves - my idea was that if it's possible to read colour values in lightroom, then it checking each colour square without then with the two filters, especially the greens and blues, could give an idea how the on-lens filter affects specific ranges in the spectrum.

I'll give it a go.

EDIT - I ran the test on the GoPro and LX10 - test details are here
Working from the LX10 raw files, I get the following data for WB in lightroom, with different filters:

 

No filter, raw, camera WB set to 6000K to match light supposed to be 6000K

- white balance "as shot" 5300K, +19 Magenta

- corrected white balance 5000K, +28 Magenta

UR-PRO acrylic
corrected WB 2350K, -14 Magenta

UR-PRO glass 55mm
corrected WB 2250K, -8 Magenta

UR-PRO (?) glass 2
corrected WB2300K, -23 Magenta

Keldan SF -1.5
corrected WB 3050K, -27 Magenta

original Magic filter
corrected WB2950K, +24 Magenta

Howshot
corrected WB2200K, -32 Magenta

However, I'm wondering if there is a way to use LR to measure the impact of the filter on greens/blues? I didn't have a full colour checker but do have a few colour squares in my test picture.

Once I'm here:

Is there any way to measure the effect of the filter is having on each of the colour squares?
Data seems identical when I move the dropper on both images, so I must be doing something wrong.

The idea would be to pinpoint broad differences in the way each filter affects a colour range, to highlight differences.

 

Thanks!

b

 

 

Edited June 25, 20241 yr by bghazzal

I ran the test raw stills again today, testing just the UR-Pro acrylic and the Original Magic filters.
White balance was set to 6000K then to NATIVE (flat).

 

Results are pretty much identical on both setting, and as follows:

 

NO FILTER, WB set to NATIVE

As shot WB 5500K Magenta +13 

Corrected WB 4900K Magenta +11

 

(for reference NO FILTER, WB set to 6000K, supposed calibrated light output gives:

As shot WB 5200K Magenta +6 Corrected WB 4900K Magenta +9 - filtered readings are identical)

 

UR-PRO acrylic, WB set to NATIVE

Corrected WB 3100K Magenta -44

 

Original Magic, WB set to NATIVE

Corrected WB 3500K Magenta +20


As observed on the LX10, a major difference is that the rebalancing with UR-Pro gives a negative Magenta reading, whereas rebalancing with the Magic gives a positive Magenta reading.

If i'm calculating correctly, based on GoPro raw files readings:

- the UR-Pro SW Cyan filter warms the light by 2400K (5500K to 3100K), and increases the magenta by +31 units (+13 to -44)
 

- the original Magic filter warms the light by 2000K (5500K to 3500K so 400K cooler/less warm than the UR-Pro), and decreases the Magenta by -31 units (+13 to +20)

There is a 400K warming effect difference between the two filters, which is not much, however for the original Magic to match the UR-Pro's handling of magenta, you would need to boost magenta by +76 (+14 > +62)...

 

At a quick glance in lightroom, setting the original Magic's wb to 5900K and boosting the magenta to +62 gives a very similar result

 

 

Modified original Magic, with WB set to 5900 and Magenta boosted to +76

 

I posted more illustrations in this thread
 

Results are now visually quite close for such rough measurements.
But while the results are visually similar, the histogram still shows significant differences in colour distribution.
To fine-tune this, it would be interesting to get readings on main individual colour channels (squares) as well, see how both filters affect them, but I'm not sure how to approach this.

 

cheers

b

Edited June 26, 20241 yr by bghazzal

As a follow-up, I ran some tests today on the GoPro with a combination of two stacked gels, one original Magic Filter gel and one Keldan Spectrum SF-15.

 

Tests were done on an overcast morning, in murky greenish-blue water, in tropical ambient light only (east Bali).

As in the previous tests, GoPro7 was on flat profile (WB native and GoPro colours), auto ISO locked at min 100 and max 1,600 (which is what I usually use for wide angle tropical ambient light shooting with the GoPro, max 800 if possible), 4K, 60fps, medium fov.

 

Note: AOI wide lens was not used as the person handling the camera for these tests - who happens to be my wife - couldn't be bothered with the extra weight 😅

 

Quick summary: not usuable / a practical solution at depth.

- good in the shallows (the Keldan gel evens out the Magic Filter), but too much light loss at depth (combined exposure loss should be Keldan -1.5 Ev and Magic -1.6 Ev so a total of roughly -3 ev - too much to handle for the GoPro at depth in today's murky conditions, footage was grainy, meaning the camera probably pumped up to 1,600 ISO around 15m)

 

The other issue is the Magic Filter's orange/magenta spike at depth, already noticed on the previous test. The Keldan gel doesn't help with this, and simply reduces the colours data making it to the sensor.

 

Here are some quick screenshots:

 

- 8m depth, on a flat plateau
worked well given conditions -  white balanced and quickly graded in FCPX (looked good just after setting the WB, plenty to work with...)

 

 

 

 

However, deeper and with less light on the slope, things got ugly...

18m depth, on the slope
 

 

While the footage isn't pure garbage, it's quite desaturated (which looks ok-ish) but the issue is really that's there's really not much left to work with.

The marked orange/magenta dayglo boost of the Magic, already noticed on the previous tests, is still there, waiting to be revealed....
All it takes is boosting the highlights+midtone saturation to the max, to see what colour info we really have to work with:

 

 

Ouch...

 

The other issue being the grain - ok, conditions were really not great and got worse during the dive, low light and particules, but it's still very grainy - other footage is worse in this respect.

This is something to keep in mind when working on stacked filters - on my aging GP7 at least, -3Ev is too much for the camera to be practical, unless staying above 10m in tropical light.

 

I guess a loss of -1.5 to -2 Ev is the sweet spot.

 

 

Edited July 1, 20241 yr by bghazzal

I have been following this discussion with great interest, and learned a lot, thank you.

 

I recently bought a Gopro and I'm planning to film in flat profile and colour grade the video with Davinci Resolve in post.

 

Does it make sense to use a grey card and  start each recording with videoing the grey card at the beginning so that I have a "white reference" to be used in post?

 

39 minutes ago, Jochen said:

I have been following this discussion with great interest, and learned a lot, thank you.

 

I recently bought a Gopro and I'm planning to film in flat profile and colour grade the video with Davinci Resolve in post.

 

Does it make sense to use a grey card and  start each recording with videoing the grey card at the beginning so that I have a "white reference" to be used in post?

 

Thanks Jochen, glad you find the discussion interesting!
 

For the grey card, I would say yes, if you can be bothered to do it.
It will be more precise, and having the same exact same reference (especially a good one like a wb card) on different clips make life easier in post.
 

The only issue is that white balance is also relative to the distance to a subject, and you will be holding it at arm's length on a cam with a relatively wide lens, which might be a little close, but it still usually works quite well.

And even if it doesn't, it's only one possible reference point.
Since you'll be picking the WB setting point in post anyway, so if you find it doesn't work as well on a shot, you can always choose another one.
 

I didn't carry a card for most of the GoPro footage I've shot, but found myself using mostly the same references in post for tropical ambient light, mostly:

Other diver's tanks (works really well, especially aluminium tanks like AL80s), diver's bubbles, also the classical sand (sand can be a bit of a hit and miss depending on conditions and sand type), or bits of white rocks in the sand. Certain light skin tones / fin colours (white Gull fins...) can be good as well.

If there is a reef, there's often a piece of bleached coral somewhere (tips) or other whitish elements in the substrate.

 

But filming a proper WB card will help with consistancy - just film it a couple of second at the start like you said, holding the card as far as you can reach and in the direction of your shot and ideally with the sun in your back, like you would for manual white balancing.

 

Looking forward to seeing the results. DaVinci is great for grading - if you put sufficient time learning to use it.

I'd started working on it but unfortunately my current laptop isn't powerful enough to get fluid playback, even running from an external SSD and using proxies, whereas FCPX works fine natively that way. There was the option to edit in FCPX, export to DaVinci to grade, but with no fluid playback on DaVinci it's a nightmare.

Planning on jumping in again when I have access to more processing power.

 

cheers

b

Edited July 19, 20241 yr by bghazzal

thank you for the detailed answers! I do have a grey card so I will give it try in a couple of weeks in Komodo. 

 

For most dives I probably will have video lights with me as well. So I am thinking to use a flat colour profile without lights (and maybe a red filter) and auto white balance when using the lights.

 

Will post some results when I am back.

 

again thank you for your advise.

Plenty of posts about red filters 😜

I was wondering if anyone has tried GoPro labs and the beta firmware for using “Log”, in the GoPro labs page says:

LOGB=logbase,offset - Super experimental, alter the log encoding for more dynamic range, or for a closer match with other camera’s log curves. i.e design your own flat profile. Ideal for use with 10-bit, and the existing flat color setting.

P.S. I’m posting here but for not creating a new post, I couldn’t find information about that.

15 hours ago, canislupus said:

I was wondering if anyone has tried GoPro labs and the beta firmware for using “Log”, in the GoPro labs page says:

LOGB=logbase,offset - Super experimental, alter the log encoding for more dynamic range, or for a closer match with other camera’s log curves. i.e design your own flat profile. Ideal for use with 10-bit, and the existing flat color setting.

No clue as I only have an older model, but I'm quite curious as to what this will change on such a camera (log is a little tricky to use on bigger cams as well from what I gathered).

While the results might expand grading options, I doubt it will be a "filter-killer" however
The gold-standard for manual UW white-balance is the Canon algo, which gives lovely results, but is most likely lovely because it shifts certain hues (greens to yellows) which gives a pleasing end result, rather than going for a truly accurate WB, and in this it is akin to using a filter.
Canon also does this on certain camera models, such as this currently viral old G7something model (the name of which escapes me) it seems to be something of a constant, generating aesthetically pleasing results ("Canon colours")

In the shallows, no problem, but below a certain depth (usually 10m but this is heavily conditions/location dependent) ambient light underwater image making is diving with a strong colour filter on the light source, and there's only so much camera manual balance can adapt to and compensate for before being thrown off-balance. Water filtration of sunlight, the effect on the colour spectrum, is more complex than a simple cooling of light temperature.

That said, anything that can record more flat data will help work on the footage colour balance in post, so I'd be curious to see the results of flat log footage shot on a GoPro!

Edited September 9, 2024Sep 9 by bghazzal

9 hours ago, bghazzal said:

No clue as I only have an older model, but I'm quite curious as to what this will change on such a camera (log is a little tricky to use on bigger cams as well from what I gathered).

While the results might expand grading options, I doubt it will be a "filter-killer" however
The gold-standard for manual UW white-balance is the Canon algo, which gives lovely results, but is most likely lovely because it shifts certain hues (greens to yellows) which gives a pleasing end result, rather than going for a truly accurate WB, and in this it is akin to using a filter.
Canon also does this on certain camera models, such as this currently viral old G7something model (the name of which escapes me) it seems to be something of a constant, generating aesthetically pleasing results ("Canon colours")

In the shallows, no problem, but below a certain depth (usually 10m but this is heavily conditions/location dependent) ambient light underwater image making is diving with a strong colour filter on the light source, and there's only so much camera manual balance can adapt to and compensate for before being thrown off-balance. Water filtration of sunlight, the effect on the colour spectrum, is more complex than a simple cooling of light temperature.

That said, anything that can record more flat data will help work on the footage colour balance in post, so I'd be curious to see the results of flat log footage shot on a GoPro!

Hi bghazzal,

I was not thinking about log a as an alternative to filters but as a “add-on”.

I will try to give it a try, for what I understand you can always go back to previous firmware in case that “not official” Gopro Lab” doesn’t work.

I like the idea also that with that firmware Gopro can read QR codes underwater and change settings alone.

Thanks for the info.

I don't want to sound like a pessimist, but I'll tell you what my impression was in an admittedly very limited use case.
Basically I had 2 GP11s, one GP8 and two GP5s, shooting the same scene in 50 cm depth. I started enthusiastically with gopro labs fw, 10 bit, high bitrate and log profile. My buddy was very skeptical and left his GP11 pretty much standard: 10 bit color Natural. Both had fixed WB 5000K.
We wasted several times doing color correction and grading of the gopro files with all features enabled only to arrive, after much effort, at the same quality as the standard one! 

I basically removed all the extra settings. By the way the GP with the high bitrate also consumed more battery while the most important thing for me was just the battery life.
In the end we left the gopro labs fw only because it was convenient to configure the various gopros on the fly with a ready-made qrcode with all the settings and exact time.
Again, maybe in another scenario the result would have been different (getting a creative look) but I remain very skeptical. As much fun as it can be to do the experiments, in the end no matter how hard you try, the sensor is what it is. The real mojo of these cameras is in the marketing.

9 hours ago, Davide DB said:

I don't want to sound like a pessimist, but I'll tell you what my impression was in an admittedly very limited use case.
Basically I had 2 GP11s, one GP8 and two GP5s, shooting the same scene in 50 cm depth. I started enthusiastically with gopro labs fw, 10 bit, high bitrate and log profile. My buddy was very skeptical and left his GP11 pretty much standard: 10 bit color Natural. Both had fixed WB 5000K.
We wasted several times doing color correction and grading of the gopro files with all features enabled only to arrive, after much effort, at the same quality as the standard one! 

I basically removed all the extra settings. By the way the GP with the high bitrate also consumed more battery while the most important thing for me was just the battery life.
In the end we left the gopro labs fw only because it was convenient to configure the various gopros on the fly with a ready-made qrcode with all the settings and exact time.
Again, maybe in another scenario the result would have been different (getting a creative look) but I remain very skeptical. As much fun as it can be to do the experiments, in the end no matter how hard you try, the sensor is what it is. The real mojo of these cameras is in the marketing.

Hi Davide,

Lol, that was a reality check!

Good to know, before I even tried, the battery life reduction itself it’s big a limitation.

Thank you very much for the info

3 hours ago, canislupus said:

Hi Davide,

Lol, that was a reality check!

Good to know, before I even tried, the battery life reduction itself it’s big a limitation.

Thank you very much for the info

As @bghazzal's tests have shown, certainly in a real dive having at least a “flat” starting image helps a lot with color correction but in my case it was practically like shooting out of the water (50 cm in fresh water).

Under these conditions, a GoPro already gives its best with classic settings. There was almost no color absorption, and the color differences between the various GoPro, shooting the same scene, were due to the different orientation relative to the sun. So it was enough to set the WB to 5000K (sunlight) and everything was more or less fine.

Another nasty blow was to realize that filming the same static scene at 1080@50p with a GP5, GP8 and GP11, color aside (easily adjustable in post), the quality of the shot was virtually the same. There was not this abyss that we are led to believe by the hype. In the most extreme cases, a pass of Topaz and the shots were identical. Sad but true.

I have seen several videos with mind blowing creative looks obtained from the Log files but these examples only show that it is possible to work with it but none demonstrate that it cannot be done from the standard Protune settings.

 

I haven't updated this thread in a while, but have been experimenting with UR-Pro filter replacements on my (indestructible) GoPro 7 black.

It's now paired with an AOI UWL-03 wide lens (old model), and, after a bit of trial and error detailed in this thread,

now filtered by a Rosco fluorofilter gel placed inside the housing.

The current rig looks like this, minus the AOI lens (I use the AOI handle on a ball mount, which allows for better shooting positions and storage - most of the time I shoot as is, with the handle on left side, and my right hand directly on the housing, which works great).

The filter gel is inside the GoPro Supersuit housing (but got a little wrinkled on install unfortunately, as you can see on the pic)

This particular fluorofilter gel is very close to the lengendary UR-Pro Cyan, as explained in the thread linked above. It works really well in blue water in the optimal ambient light zone of 5 to 15m, and can be stretched a little above or below depending on light conditions.

I haven't been diving with the GoPro that much, but after an initial first test a few months back in super shallow water - really too shallow for a filter - (clip here )
I finally did some proper dives with it yesterday, and the results are nice, and fine for grading in post, with the filter really coming to its own around 10-15m (there wasn't enough sunlight to shoot below 20m yesterday).

These are captures from the GoPro7 video footage (4K, 60fps, wide), shot at around 10m on the GoPro7 with the AOI UWL-03 lens
Blue water, average viz (15m) with particules in the water and quite overcast.

This is at 10m, the blurry spot on center left comes from damage to the filter gel itself mentioned above.

I the water in Okinawa is very blue, so I would probably actually desaturate the blues a little (hue vs sat) for a more moderate balance in the final clip, but this illustrates what I have to work with.
The colour range of the coral is very natural, identical to what you'd see in the shallows (Indonesia this is not)

As stated above, there wasn't enough sundlight to work in ambient below 20m in yesterday's overcast conditions (not enough light = too much noise below 20m), but this is a shot of a blotched fantail ray / ribbontail ray swimming under me at 25m (bottom is a 40m plus).




While using filters seem like a thing of the past, I still find that for filtered ambient light footage, shot in a flat profile and rebalanced in post is the way to get the most out of action cameras.
While shooting filterless works fine in the shallows, I've never been able to emulate these kind of results without a filter at diving depth, at least not with the same colour balance.

Keep in mind water is a itself a filter on our ambient light source (the sun) and this causes action cam colour palette to be way off the deeper we go, whereas filtered footage helps regain a more pleasing, natural balance on these cameras incapable of manual white balance at depth.
The key is to shoot in flat or as flat as possible with the filter, then reset the white balance in post before grading. It's quite magical.

Here's a little walkthrough of the process on one of the video captures.

Straight out of camera (SOOC) flat footage looks like this:
(the balance is already not bad, but there is a warm colour cast. This warm colour cast is actually a desirable one, since it will help restore a more even/balanced colour palette when setting the white-balance point)



I then set the white-balance point (rebalance the image) in post, which also corrects the colour cast:
(this replicates, in post, what you would do at depth with a camera capable of manual white-balancing at depth. The filter has helped us obtain a more balanced image by mitigating the water's filtering effect on sunlight )



I then proceed to grade the footage to taste:
(here's a less saturated alternative to the one I posted above)



or if you want to pop the saturation a little, working from pre-balanced (filter) flat footage gives you latitude to do so, even on the ancient GoPro7... Imagine what it would be on 10bit footage!



However, actual filter quality is essential, and filters are far from universal.

My favourite filter on the Lumix LX10, the Keldan SF-1.5, doesn't work well on action cams, as it's too weak, and best reserved for cameras capable of manual white balance - same goes for Magic Filters.

Unfortunately, many commercially available filters are really not designed by people having looked into filtering characteristics and are just very bad (Polar Pro etc), and also used by people not shooting in flat and rebalancing the footage in post, which tended to give filters a bad-name.

A filter like the beloved, proven UR-Pro, or others with a similar fluorofilter profile, really works best for this kind of approach.

***

So here we are...
It works. This is not a "get the best footage SOOC approach. But I really think that when shooting in ambient light working on the footage in post is just an integral part of the process, and has to be taken into account.

Artificial light (video lights, strobes...) dominant shooting is more forgiving and can be great SOOC, but for ambient light, you have to make some adjustements at some point to get a good colour balance.

And this is even more important for cameras which can't manually white balance at depth, like our current action camera range.
This is where the shoot in flat profile and manually set the white balance in post workflow really works well to get around this limitation.

And adding a good filter to the mix will help when setting the white balance point, counterbalancing the filter on our light source (water on sunlight, of which you need plenty of for full ambient light shots), as seen above.
This results in a more even aesthetically pleasing colour palette, without the odd hues or dayglo colours you often see on action cam footage shot in "auto" mode, where you let the camera try to adjust the colour at depth...

I would really like to try this approach on more recent generations action cameras - especially with 10bit colour - so we can compare filtered and unfiltered end results, and see if filters are really a thing of the past for action cams at scuba diving depths...

cheers

ben

Edited July 28Jul 28 by bghazzal
added SOOC camera footage

Thanks for your effort. I look forward to see the turtle clip.

IIRC 😉 you should have a Lee Dark Salmon gel which appeared to be very promising in the land test.

When do you plan to test it?

P.S.

Rosco 3310 is EOL so we need another champion

1 hour ago, Davide DB said:

you should have a Lee Dark Salmon gel which appeared to be very promising in the land test.

When do you plan to test it?

P.S.

Rosco 3310 is EOL so we need another champion

Yes, the Lee Dark Salmon is the best contender out there. As detailled in the UR-Pro filter thread, the UR-Pro cyan spectrum profile is basically that of a fluorofilter, a type of filter that were designed to "Convert U.S. Cool White or Daylight type fluorescent lamps to 3200K photographic tungsten and remove the excess green." to quote Rosco.
The issue is that fluorescent lights have been phased out by LED lights, rendering fluorofilters obsolete in the lighting world.

The Lee 08 Dark Salmon (LDS) is a good alternative. It was actually already tested in water and works fine, but with some caveats:
As I wrote in the UR-Pro thread after the side by side comparison, it is stronger / darker (and a bit warmer) than the UR-Pro - meaning a little more loss of light / ev, and also a slightly deeper tint in the reds - this is visible when looking at the camera's ISO sensor data, with a higher ISO on the LDS.

Yet what this also means is that, as expected, the Lee gel actually works somewhat better than the UR-Pro when going deeper, but this is a give and take, as it means a greater loss of light - which could be fine in the tropics, less so elsewhere.
Handling of the blues is also a little different, as seen in compared curves:



A fluorofilter profile like the 3310's is closer to the UR-Pro's original profile, in fact almost identical.

There are probably other fluorofilter gels still available out there somewhere, the key is to find one with a curve the closest to that of UR-Pro cyan filter, detailled in the dedicated thread here https://waterpixels.net/forums/topic/1414-ur-pro-filters-info

The logic is pretty straightforward, sea water filtrates sunlight and has a cooling effect, adding green / cyan.
A fluorofilter is specifically designed to mitigate this. Yet as you can see on the graph above - and this is where a fluorofilter is different from a simple green-cutting filter, it still lets deeper blues through (= nice seawater blue).

Just look at the flat SOOC flat GoPro video footage capture posted above:

You can actually see the filter at work.
Image has a warm cast, greens/cyans are cut (which is what usually sticks out on unbalanced ambient light footage shot without a filter...) BUT, very importantly, the deeper blues are still there.

Rebalancing the image in post (by setting the white balance point, as you would normally do underwater, at depth using a slate with a manual WB capable camera) is made easy, and the results are more balanced.

Rebalanced image after setting the WB point in post:


Footage is then colour graded to taste:


It's an efficient work around for getting good colours UW in ambient light out of action cams, because these cameras can't manually white-balance at depth (which is standard procedure for shooting underwater video)

And beyond Canon-colour magic (where the camera's handling of manual wb / colour palette is somewhat like having a built-in filter), I'm still a big believer in the utility of filters to get more balanced, natural looking ambient light UW video footage at diving depths.
The trade off is in stops of light of course, but for typical ambient light shooting depths, it's practical in most locations with enough sunlight to do so.

However, the technical key points - and reason I opened this thread to begin with - to achieve this on an action cam are to use a well designed filter with the characteristics mentioned above (lets blues through, cuts greens/cyans, warms), to shoot in flat profile (to stop the action cam from trying to adjust things on its own, which it struggles to do at diving depth with filtered sunlight), and to set the white balance point in post-production.

I've been experimenting with this technique since the GoPro4. No point waiting for the GoPro21, Ace 720 or DJI Action10, or the next miracle in action-cam colour handling at diving depth. This just works.

cheers!
ben

Edited July 28Jul 28 by bghazzal

 

To wrap it up, I would argue that shooting in ambient light with (well designed, appropriate) filter still gives better results than in camera software WB/colour correction, despite amazing technological advances made.



Even in 2025, this should be the go-to method for getting a good colour balance when shooting underwater in ambient light on action cams and/or cameras not capable of manually white-balancing at depth, when working within the following set of parameters:

1.     you will work on the footage in post production to reset the white-balance point - working in post is a must for ambient light footage at scuba diving depths anyway.
Beyond grading, the main “work” with action-cams will be resetting the white balance post in post-production, rather than at depth as you would do when working with a manual WB capable camera

.
So yes, using filters on non-manual white-balance capable cameras is NOT a good way to get good results Straight Out Of Camera, since you will need to at minimum rebalance the footage in post.
This is a major difference with using filters on cameras capable of manually white-balancing at depth, where the SOOC result will already be white-balanced and good as is. The action-cam workflow implies rebalancing in post.

2.     you are shooting in “flat” or flatish profile - ie. limiting what the camera will try to do in-camera through software correction.
This is essential for grading the footage afterwards, and avoiding odd hues generated by the cameras “underwater modes when setting the white-balance in post, which usually boost the red channels (degrading the image and rendering it difficult to grade when it comes to colour balance).
Another issue being potential variations of colour balance/ treatment within a sequence, which you wouldn't have when locking the adjustments. Not a problem for stills, but definitely a problem for video.

 

3.     you are shooting within the underwater ambient light “Goldilocks zone” – this varies depending on location and local conditions, but can be defined as a depth where ambient sunlight filtration becomes so strong that the camera will struggle with white-balance and colour, yet a depth which still offers enough light to get good results in post as seen in the examples posted above.


Typically, for strong sunlight locations like the tropics, this would be below 5m (above which water's filtration effect is so weak that the camera can handle the wb changes), and usually down to roughly 20m, stretching to 25-30m depth in very strongly lit clear water locations.
8m-15m is usually the depth range where ambient light works the best.


Beyond depth, you also need enough workable ambient light.
A filter will make the camera lose stops of light, typically 1 to 2.5 stops, which is a big tradeoff, but worth it when shooting at the right depth range / conditions.
 
Usually around 20m+, things begin to breakdown both because of the lack of light (=noise, less contrast) and increased filtering effect of sea water (less colour info making it to the sensor)




4.     You are using a good filter, ie. one which is well designed to do the job properly – the job typically being – in blue water -  cutting cyan/greens while letting deeper blues through, and warming up the image hitting the sensor, which will help the camera white balance correctly being mitigating sea water’s filtering effect on sunlight, either manually at depth or in post-production
.

Shooting in green water, the filter should be different, typically more magenta, taking into account the difference in sea water’s filtering effect.
Typical well designed filters will have a fluorofilter like effect on the spectrum, examples being UR-Pro (no longer made), Keldan, Magic…

Keep in mind that many "red" filters on the market do not seem to have been designed with a proper understanding of how it works and what the filter is supposed to do, beyond "warming"... it's just not a question of slapping a red piece of plastic on the lens and calling it a day...

 

5.     You are shooting in full ambient light, or, in a mixed-lighting scenario, with filtered artificial light (ambient filters on the video lights, in order to emulate water’s filtration effect and even out spectrum difference between ambient and artificial light, see the Keldan system or other approaches along those lines).

If shooting in an artificial light dominant scenario, just drop the filter. Same goes for the shallows, in the 0-5m depth range for instance.




Just keep in mind that there are many ways to do this wrong, even with good material.
Grading and colours are highly subjective of course, but as an example, this auto-white balance Ace360 + filtered artificial light clip is an interesting illustration of a failed approach to the problems are play.
There are plenty of others out there, most stemming from auto-white balance and in-camera corrections...

To make it clear, more than using a filter, the most important point of this ambient light action-cam workflow's is actually working in a flat profile and resetting the WB in post.
This is the key.
Adding a good filter will improve white-balance results, be it in post-production for action cams or at depth for manual white-balance capable cameras.

 

---

And yet within this set of parameters, shooting flat ambient light footage with a filter will give you great workable results, often superior to unfiltered, in-camera adjusted ambient footage in terms of colour balance.
This is especially true on action cams currently incapable of manually setting a white-balance point at depth.

 

Let’s dig into the reasons why this is the case.

1. The problem with in-camera software white-balance correction underwater

Ok, so we’re in a situation, in our day and age, where cameras have software corrections capable of doing a great many incredible things.
So why - despite the marketing and consensus stating that filters-are-a-thing-of-the-past, are filtered footage results still generally better than in-camera software-corrected results in terms of colour balance?
Why are filters still used by blue-chip professional production, but are seen as passé in the amateur / semi-pro world?



Well, if you try to work on in-camera software corrected footage, and attempt to fine tune white balance or grade the footage, by setting the WB point in post on an easy white/grey target (sand, diver’s tank, bubbles, bleached coaral etc) you'll often end up with a weird red or magenta peak and a weird colour balance.
 

I've done this a lot. Many times, I've tried editing unfiltered, non-flat GoPro footage from colleagues in locations where I was working. It’s bad, and just doesn't work.
Rebalancing white balance makes colour balance fall apart, so you have to work with what you have, which limits possible adjustments.
This happens mainly because the camera software boosts the red channels in an attempt to correct for the underwater blue cast on ambient light.

This creates a dual problem for us:

• The camera is artificially boosting the reds, which degrades image quality.


• There's generally still a strong cast (often cyan/green/blue), and if there isn't (eg. "underwater mode"), the colour palette isn't very balanced or natural looking.

When setting WB at depth or in post, you're saying "this area should be gray/white", which should lead to canceling out the blue/cyan cast.
But if the reds in the footage are already over-boosted by in-camera softwae correction, the result is unnatura, with all sorts of strange magenta horrors, etc.



2. Why shooting flat and/or using a filter generally works better in ambient light situations

If the footage had been shot in a flat colour profile, the reds wouldn't have been boosted, allowing a cleaner WB correction, and colour balance, without magenta distortion issues.

This is obvious when shooting stills in RAW mode for instance, which is standard for still photography.


A flat (or flat-ish) colour profile will allow you to work on those reds, magentas manually in post, without having to deal with varying baked-in colour corrected footage.

Even better, using a well designed physical warming filter on the camera (like UR-Pro or equivalent) acts on the ambient light before it hits the camera sensor:

• The sensor records a warmer image, reducing the need for software correction.


• With a good filter that still allows deep blues to pass through (eg. fluorofilter type profile), you end up, after resetting the WB point, with a warmer, more neutral, and more accurately balanced image than you would without a filter.

Deep blues in the background are preserved, while the foreground gains accurate tone, making for a more natural looking, balanced image.

This is especially important because setting underwater WB is really about how much “stretching” has to be done to deal with the filtering effects of sea water on ambient light.

The more WB stretching is required, the more image degradation you'll have.
A physical filter on the camera works by reducing the amount of stretching required to rebalance the image

To summarise, filters mechanically "warm" the ambient light-lit image before it reaches the sensor.

This:

• Enables better manual WB capacities at depth or in post

• Avoids needing baked-in software corrections from the camera, which are hard to work with in post in post.


• Will give you more depth – the filter’s effect will extend to deeper in the image, meaning you lose background colour further away, and with less of a drastic drop than software correction


The main dowside being, of course, the infamous loss of stops of light, which can certainly be a deal breaker in certain shooting conditions.

In contrast, software-based in-camera colour correction:

• Manipulates individual colour channels, with results that can be good or bad

• Often leads to baked-in artefacts and hues, and uneven colour balance/palette

• Degrades the footage
, making difficult to work with in post

• Is not stable, and can vary within a sequence, which is problematic

3. Limits of filter use and manual white-balance setting (at depth or in post-production)

As already mentioned above, even with a good filter:

• In clear well lit waters (tropics for instance), the filter's effects typically break down beyond 20–30 metres depth in good conditions.


• You can still set WB, but the colour cast becomes too strong, and image balance collapses.
You would need a stronger filter, but then you would lose to much ambient light, which itself becomes rarer the deeper you go
... Catch-22...

• So after a certain point, there’s less ambient light, and the filtering effect of seawater becomes too strong - setting WB in these conditons (at depth or in post) just stretches the channels too much, leading to distortion, like when working without a filter. In such stiuations, it's best to accept the colour cast or to work in artificial light.




• When shooting in the shallows, say at snorkeling depths, the water’s filtering effect on sunlight is mild, and working on filtered footage at such depths will mean actually cancelling out the filter’s effects to set the white balance – it's possible, but really there’s no reason to shoot with a filter in the shallows, especially since required hue corrections will degrade the image.

• Available ambient light to work with. In some sea conditions, there’s just not enough ambient light to work with a filter. In this case, as at depth, it’s best to accept the colour cast on the ambiet light footage and work with that, or use artificial light


• Filter design vs. sea water qualities. Most filters are designed for blue/cyan water, which is ambient-light paradise, and thus not ideal for greener waters.
Because cyan-filters cut off greens, if much green is cut, the water may end up looking unnaturally coloured, and the balance may be off compared to using a purpose-designed green water filter.

UR-Pro did have a green water filter, as does Keldan if I recall correctly. These need to be experimented with, but since greener waters are usually darker ones, the light-related linitations mentioned above might also come into play.






---

To conclude, one could say that letting camera software handle underwater colour correction is like trying to shoot on land using coloured lighting and expecting the camera to fix everything digitally.

On land, beyond setting the kelvins to best match your light source, if the light used has too much of a colour cast, you would probably add a lighting gel to adjust it or just simply change the light, rather than letting the camera try to get rid of the cast for you through some sort of software adjustement...

Well, this is what a physicial filter on the camera is doing underwater in ambient light, with our own water-filtered light source (the sun). Sunlight at depth if a filtered light source, with a cast.
Most modern camera can handle a light cast (say in the shallows), sure.
But when dealing with strong blue/green/cyan cast (eg. 10m depth or so), it is still best - even in 2025 - to physically act on the cast itself than try to let the camera handle it, and will give you more workeable footage in post, and generally better results overall.

Voilà, I hope others find this approach useful, even if it's seen as a outdated, and thing of the past.
Just try it for yourself, but do it right. It works.


Cheers!

Ben

 

Edited July 30Jul 30 by bghazzal

I just read through the entire post and I found it fascinating, I've learned a lot! Also kudos for your approach to this topic (explanations, experiments, etc) - it honestly felt like reading a scientific paper. I can't wait to run some experiments of my own!