The Warming Diffuser Discussion ( and Gels ) for Bluewater Strobe Photography

[Adventurer]

Hello, please help me to understand something were I basically do not agree with the mainstream advice given these days:

 

So when in tropical waters (bluewater) many (pro) underwater photographers recommend a warm color temperature strobe as it should render background blue more nicely when balancing foreground reef and background bluewater.

 

This piece of advice is given very often in forums, YouTube videos. Last but not least Dr. @Alex_Mustard himself has convinced several manufacturers to offer warming filters if the underwater strobe itself has a cold color temperature.

 

In most cases this comes with the price of sacrificing strobe power as the warming gels and diffusers will absorb photon energy.

 

My classic approach is to render the correct bluewater by shutter speed - not too much by white balance.

 

Of course your replies will also include that strobe color temp will very much depend on personal taste, but please let’s spare everyone with that argument and concentrate on getting the best technical result or a time saving digital workflow.

 

So basically what’s the real benefit ?

 

I have used warming diffusers on Backscatter HybridFlash HF-1, Marelux Apollo III 2.0 and INON S-220 with Canon R6 Mark II in the Red Sea and must say I really cannot subscribe to the effort.

 

It makes me wonder if I understood @Alex_Mustard or @DreiFish correctly, when they vote for warm gels or diffusers?

 

So question to both of you and others:

 

Do you leave the cameras white balance on AUTO or do you MANUALLY WB on the strobes color temp to get the best foreground background mix?

 

How should this benefit the RAW file when adjusting WB during image processing?

 

Is this considered beneficial for competition photographers who participate in traditional categories with minimal editing allowed?

 

Most contest categories today allow separate masks + processing of foreground and background, so this becomes obsolete there.

 

Get your image done correctly on location would be a time saver argument.
 

Personally I found that my AUTO WB with warming diffusers got distorted pretty badly compared to cooler strobes in tropical waters and also varied heavily depending on diving depth. When manually white balancing the strobes with warming diffusers + working distance on sand the results got pleasing

directly out of the camera, but if the depth, angle and scene changed the colors got pretty bad. You would need to redo manual WB several times during the dive, to stay optimal. This would make you loose quite a few wildlife scenes that happen spontaneously.

 

So what’s your say ?

Edited Thursday at 05:58 PM by Adventurer

[Dave_Hicks]

It depends on the strobe. I never used diffusers at all on my Inon 330 or Ikelite 161 strobes and set AutoWB. Any adjustments to color temp could be made with WB in post. With the HF-1 strobes I am using the 4500k diffusers despite the drop in power. They are colder than the Inons and I like to look with AutoWB using 4500k. These strobes are extremely powerful, so I don't worry about loss of light. I rarely use more at 1/4 or 1/2 in my local green cold-water locations anyway. I have not used them in tropical waters yet, and I will experiment more when I get the chance later this year.

[Klaus]

As far as I understand it the warmer strobe colors are a benefit if you (or your camera) adjust WB globally. If you apply a mask during post processing and adjust the WB separately for foreground and water, then I can imagine that the strobe color is not so important any more. I have never tried this, though, because I find making these masks tedious. 
but above all, I am already super-happy if I get the balance of strobed foreground and background water right for once…

[Dave_Hicks]

41 minutes ago, Klaus said:

As far as I understand it the warmer strobe colors are a benefit if you (or your camera) adjust WB globally. If you apply a mask during post processing and adjust the WB separately for foreground and water, then I can imagine that the strobe color is not so important any more. I have never tried this, though, because I find making these masks tedious. 
but above all, I am already super-happy if I get the balance of strobed foreground and background water right for once…

Lightroom mask creation is a breeze now with AI assisted masking tools. Very powerful and much faster than it used to be.

[TimG]

I agree with Dave. The latest version of LR makes the use of masks really easy and very powerful. Removing unwanted items is amazing.

[shokwaav]

Lightroom masks have improved a long way, but it will still struggle with fine details such as coral. 

 

I also prefer getting everything correct in camera. Set the WB to the level of the diffusers and make minor global WB corrections in lightroom.

[Chris Ross]

6 hours ago, TimG said:

I agree with Dave. The latest version of LR makes the use of masks really easy and very powerful. Removing unwanted items is amazing.

While masks are very good, my view is it is always better to not mask, it's less work in post processing for a start and unless you adjustments are limited getting transition between masked can be an issue.

[Chris Ross]

10 hours ago, Dave_Hicks said:

It depends on the strobe. I never used diffusers at all on my Inon 330 or Ikelite 161 strobes and set AutoWB. Any adjustments to color temp could be made with WB in post. With the HF-1 strobes I am using the 4500k diffusers despite the drop in power. They are colder than the Inons and I like to look with AutoWB using 4500k. These strobes are extremely powerful, so I don't worry about loss of light. I rarely use more at 1/4 or 1/2 in my local green cold-water locations anyway. I have not used them in tropical waters yet, and I will experiment more when I get the chance later this year.

The point of warming diffusers is that only the flash light is warmed, the light from the strobe has zero impact on the water.  To get the right balance on your subject, generally 4500K light would look too warm and you need to cool the colour temperature a little in post, this means the water will be cooled down as well if you do a global colour temperature adjustment.  You end up with deeper blues in the water as a result. 

 

As far as the original question goes in Raw files it doesn't really matter if you use a preset 4500K WB in manual or an auto WB.  The correct WB for the subject remains the same regardless and you can adjust this very easily as a global adjustment in post.  I tend to use AUTO WB and find that it works just fine, use the one that ends up closest to correct when you open it in Raw.  The whole point of the warming diffusers is it takes advantage of the fact that the subject is flash lit and the water is not. This way a global WB adjustment ends up cooling the temperature of the water.  Yes you could do this with masks but my preference is to minimise post processing if possible.

 

 

[Architeuthis]

17 hours ago, Adventurer said:

 

My classic approach is to render the correct bluewater by shutter speed - not too much by white balance.

 

Of course your replies will also include that strobe color temp will very much depend on personal taste, but please let’s spare everyone with that argument and concentrate on getting the best technical result or a time saving digital workflow.

 

So basically what’s the real benefit ?

 

 

=> Via shutterspeed the brightness/intensity of the bluewater is adjusted, but not the color/temperature/tint of the water..

 

When one adjusts the water color in post via WB, also the color/temperature/tint of the forgeround object changes and quite often becomes to cold, especially when a "cold" strobe was used to lit it. Then one has to use masks in LR and adjust the color of bluewater and foreground separately. Not only a lot of work, but often masking is not perfect and artifacts can be introduced in the photo...

=> Hence I prefer to use warm diffusers (e.g. 4500K) and then no or less adjustments are needed...

 

Wolfgang

[TimG]

40 minutes ago, Architeuthis said:

Via shutterspeed the brightness/intensity of the bluewater is adjusted, but not the color/temperature/tint of the water..

 

Yep, changing the shutter speed does indeed let you change the colour of the background water. The faster the speed, the less light gets to the sensor and the darker the background. The slower the shutter speed, the more light gets to the sensor and the lighter the background. So you can to a fair degree control the "blueness" of the background to suit the image you are trying to create.

 

As Wolfgang sets out, using the LR Tint and Temp sliders changes the whole image WB unless yuu confine the adjustment to areas isolated through a Mask(s).

 

Masks and WB can be tricky compared to using a Mask to, for example, remove a distracting element. But if its only the background and nothing which is a prime element of the subject is excluded, a Mask can do this quite well I find.

 

I used to use diffusers with the Inon Z240 strobes. But now with the Retras, I just can't see any real difference with or without diffusers.

[Chris Ross]

9 hours ago, TimG said:

 

Yep, changing the shutter speed does indeed let you change the colour of the background water. The faster the speed, the less light gets to the sensor and the darker the background. The slower the shutter speed, the more light gets to the sensor and the lighter the background. So you can to a fair degree control the "blueness" of the background to suit the image you are trying to create.

 

As Wolfgang sets out, using the LR Tint and Temp sliders changes the whole image WB unless yuu confine the adjustment to areas isolated through a Mask(s).

 

Masks and WB can be tricky compared to using a Mask to, for example, remove a distracting element. But if its only the background and nothing which is a prime element of the subject is excluded, a Mask can do this quite well I find.

 

I used to use diffusers with the Inon Z240 strobes. But now with the Retras, I just can't see any real difference with or without diffusers.

To be fully accurate, changing shutter speed doesn't change the colour of the water, it makes it brighter or darker.  Changing the colour temperature means there is more or less yellows in the blues.  The tint can also have a big impact on how the blues appear, adding magenta makes them appear deeper in colour.

 

Making the water darker however can improve the look of the water, providing higher contrast with the subject. 

 

I agree masks can be a problem - it's always better IMO to get it right in camera.  It's so easy to get carried away when processing and produce something you want to throw out when you see it the next day with fresh eyes, so keeping your processing simple is always a good thing.

[Adventurer]

8 hours ago, Chris Ross said:

To be fully accurate, changing shutter speed doesn't change the colour of the water, it makes it brighter or darker. 

I do not (fully) agree Chris. Actually you can turn green water background into blue color by just alternating the cameras shutter speed. 
 

If you look at a prism / color spectrum you will find that blue and green live next to each other on that scale. By cutting off wavelengths you can move slightly in this gradient.

[Chris Ross]

On 1/11/2025 at 5:15 PM, Adventurer said:

I do not (fully) agree Chris. Actually you can turn green water background into blue color by just alternating the cameras shutter speed. 
 

If you look at a prism / color spectrum you will find that blue and green live next to each other on that scale. By cutting off wavelengths you can move slightly in this gradient.

Sorry, but that is not how it works, changing the shutter speed changes the amount of every wavelength of light the same amount, it doesn't preferentially cut off certain wavelengths.  What can happen is on Auto WB the camera might shift the WB around on each frame or shooting a different subject might provide a bigger shift in auto WB.

 

I was out diving this morning in greenish water and took a series of shots of just the water, then copied a square out of the centre of each frame and pasted into a single file.  I did this first as shot, you can see I didn't get the same aim in each frame so exposure wasn't equal.  I then equalised exposures on all frames  and pasted another set of squares.  YOu can see the equalised brightness squares are all pretty much the same.

 

The water was under exposed a little so I then increased exposure of each frame by 1.3 stops and also pasted them into the file.   You can see that the colour doesn't really vary among the frames.  I also noted the colour temperature and tint from each frame and it moved a little bit, but undoing this I could see no change in frame colour.

 

The way to shift greenish water to blue is increase tint which adds magenta.  This may or may not be feasible depending on how the the subject reacts when you do a global tint adjustment.

 

Not saying that darkening the background water doesn't improve things, it just doesn't change colour.  Shooting with warming filters does however shift the colour of the water towards blue/cyan, removing yellow and red.

[ChrisH]

First, the effect of warm strobes is not a night and day difference, but there is a difference and if you have seen it, you can't unsee it 😉

 

Second, the effect cannot fully be done in post processing... at least I can't do it. Maybe others can, but I would argue it is a lot more effort than just getting it right in camera.

 

The effect shows mostly in warm water and if the main subject is close (a lot of strobe light reaching it). It mostly can be seen in reef scenes shot very close (fisheye lenses). 

I am not sure about the technical details of it, but as I understand hitting the subject with warm light will bring the white balance and color rendering of the camera "cooler", giving more pleasant, rich blues while retaining a pleasant foreground color (hit with warm light). So it cannot be replicated with global white balance, because it is the different light temperature between foreground and background. The closest I can get to it with post processing is to play with the color sliders for blue and aqua in Lightroom, adjusting hue, luminance and saturation.

 

[ChrisH]

I have attached three images that where shot with warm color temperature strobes: Retra Pro with filter and Seacam (4400 Kelvin without filter).

 

White Balance was on auto. No (!) adjustments to color were done in post processing. The colors are out of cam.

 

I converted it to sRGB for web display, but in RGB and with a good monitor the blues are much better.  The two shots with diver in it were shot at 25-30m depth, so the blues are a litte dark but you can bring that up easy in post.

 

With my older strobes (cooler color temperature), I am pretty sure I would have to make some adjustments to get the colors as they are now out of cam.

[Adventurer]

Nice pictures @ChrisH - must be magic „Nikon Blues“ in AutoWB 😉👌without postprocessing.

 

@Chris Ross I would like to get us all on the same page and look what’s different. 
 

I assume that both of you do not shoot RAW+JPEG out of cam, are you? So all your image go through the Adobe (Lightroom) workflow? 
 

What color profile do you have set in your cam? In my Canon‘s I occasionally like to use the magic „Landscape“ profile. This might be one of the reason, why we come up with different results and experiences.

 

Next to that, I‘d like to stick with my statement that if not correctly exposed for the blue water, the image may get a green tint or cyanized.

 

This also results the phenomenon that you can tweak greenish water into the blue spectrum with traditional in camera technique (exposure) on auto white balance.

 

Even though Chris Ross came up with a fresh lab test argument/example about greenwater, I do not agree with his results and conclusion. I took a look at your Instagram account, Chris Ross and my impression is that you did not nail the blue in the majority of your shots. When compared to Christian‘s results, Mr. Horras has definitely very pleasing blues in his examples. 
 

There are different levers that you can push in your camera to get the desired blue background. With the AutoWB and general color science camera brands act very differently, so this may also come into play.

Edited Sunday at 05:18 PM by Adventurer

[ChrisH]

8 minutes ago, Adventurer said:

Nice pictures @ChrisH - must be magic „Nikon Blues“ in AutoWB 😉👌without postprocessing.

 

@Chris Ross I would like to get us all on the same page and look what’s different. 
 

I assume that both of you do not shoot RAW+JPEG out of cam, are you? So all your image go through the Adobe (Lightroom) workflow? 
 

What color profile do you have set in your cam? In my Canon‘s I occasionally like to use the magic „Landscape“ profile. This might be one of the reason, why we come up with different results and experiences.

 

Next to that, I‘d like to stick with my statement that if not correctly exposed for the blue water, the image may get a green tint or cyanized.

 

This also results that you can tweak greenish water into the blue spectrum with traditional in camera technique (exposure) on auto white balance.

 

Even though Chris Ross came up with a fresh lab test argument/example about greenwater, I do not agree with his results and conclusion. I took a look at your Instagram account, Chris Ross and my impression is that you did not nail the blue in the majority of your shots. When compared to Christian‘s results, Mr. Horras has definitely very pleasing blues in his examples. 
 

There are different levers that you can push in your camera to get the desired blue background. With the AutoWB and general color science camera brands act very differently, so this may also come into play.

 

Yes indeed, when I used Olympus back then I was never satisfied with my blues. Even in post processing I was not getting the color/rendering I wanted. After I switched to Nikon, the blues were much "better" or should I say more to my taste. The difference was very notable. And switching to warmer color temperature strobes did get me a little more to my desired rendering of blue. But the difference between the Olympus and the Nikon was much more noticeable than switching to warmer strobes.

 

Also, what I forgot: Nikon has different AWB settings! And after switching from my D810 to my Z8 I had to experiment with the different AWB settings to get the results I wanted, as the newer sensor and processor rendered the colors (very) different! I now use the A1 setting, which is a little warmer than the standard setting, but not as warm as the A2 setting. I don't know how that translates to Canon/Sony or other manufactures.

So there are a lot of variables in those comparisons. 

 

Maybe I should try to just manual WB to the color of my strobes. I just didn't feel a need for it, as I am getting my "blues" the way I like them with my settings/equipment. But It would be a nice experiment.

 

Also: the desired "blue" is a personal preference and everybody has a different taste of what the "blue" should look like.

 

I only shoot RAW, so I don't have any jpg. My picture setting is "Standard" in the D810 and Z8 but that will only affect the rendered jpg file as far as I understand. So I don't know what translates to the Canon "Landscape" format? Or does it affect color rendering within the RAW file? At least for Nikon, I don't think so?

[Adventurer]

15 minutes ago, ChrisH said:

So I don't know what translates to the Canon "Landscape" format? Or does it affect color rendering within the RAW file? At least for Nikon, I don't think so?

Camera profiles are a strange beast and were for a long period the origin of high color discrepancies between your camera (Canon/Nikon/Olympus/Sony) and Adobe Lightroom.

 

In Lightroom you can pick stuff such as „Adobe Standard“,… „Adobe Landscape“, … „Camera Standard.“ ,.. „Camera Landscape“ - many photographers agree that the profile should be picked early in the editing workflow. They should not be mistaken with Creative Filters (of Cameras), Presets (Lightroom) or Color Profiles (AdobeRGB, sRGB etc).

 

(Camera) Profiles are the way how the camera or raw converter interpretes the early data in your RAW file. This can lead to huge variance in color and contrast.

Edited Sunday at 05:51 PM by Adventurer

[ChrisH]

2 hours ago, Adventurer said:

Camera profiles are a strange beast and were for a long period the origin of high color discrepancies between your camera (Canon/Nikon/Olympus/Sony) and Adobe Lightroom.

 

In Lightroom you can pick stuff such as „Adobe Standard“,… „Adobe Landscape“, … „Camera Standard.“ ,.. „Camera Landscape“ - many photographers agree that the profile should be picked early in the editing workflow. They should not be mistaken with Creative Filters (of Cameras), Presets (Lightroom) or Color Profiles (AdobeRGB, sRGB etc).

 

(Camera) Profiles are the way how the camera or raw converter interpretes the early data in your RAW file. This can lead to huge variance in color and contrast.

 

Ah, now I got it! my bad! I thought you meant the profile in the camera (used for the jpgs), because you refered to Canon and Landscape.

 

In Adobe Lightroom I use the standard "Adobe Color" profile for my RAW editing. The Landscape Profile has a little too much saturation in it for my taste. But you are right, it can change the look of the RAW file a lot. It really comes down to personal preference and the camera, because the colors are interpreted very differently!

[Chris Ross]

8 hours ago, Adventurer said:

Nice pictures @ChrisH - must be magic „Nikon Blues“ in AutoWB 😉👌without postprocessing.

 

@Chris Ross I would like to get us all on the same page and look what’s different. 
 

I assume that both of you do not shoot RAW+JPEG out of cam, are you? So all your image go through the Adobe (Lightroom) workflow? 
 

What color profile do you have set in your cam? In my Canon‘s I occasionally like to use the magic „Landscape“ profile. This might be one of the reason, why we come up with different results and experiences.

 

Next to that, I‘d like to stick with my statement that if not correctly exposed for the blue water, the image may get a green tint or cyanized.

 

This also results the phenomenon that you can tweak greenish water into the blue spectrum with traditional in camera technique (exposure) on auto white balance.

 

Even though Chris Ross came up with a fresh lab test argument/example about greenwater, I do not agree with his results and conclusion. I took a look at your Instagram account, Chris Ross and my impression is that you did not nail the blue in the majority of your shots. When compared to Christian‘s results, Mr. Horras has definitely very pleasing blues in his examples. 
 

There are different levers that you can push in your camera to get the desired blue background. With the AutoWB and general color science camera brands act very differently, so this may also come into play.

You are likely correct for a lot of the shots in my IG, but I would also suggest being cautious with images on IG.  I process my images in Adobe RGB and get reasonable blues but converting to sRGB they go off and I haven't discovered a magic formula to bringing them back.  In addition Facebook I know and I assume IG strips the colour profile for the image and converts it to uRGB, which is their own profile - they do this to reduce the size of the profile attached to the image, with the millions of images uploaded it saves significant bandwidth.  If I am honest I think a lot of images I'm not close enough so they don't get enough flash light - I can compensate for that but the blues probably suffer a little as a result.

 

I shoot RAW, (no JPG) out of camera, autoWB, using two Z240 with the 4600K diffusers for some of the images - mostly the tropical ones, I have a huge number of images from Sydney using the standard diffusers.  Don't use lightroom, I use Capture One feeding into photoshop.  in camera it's Adobe RGB profile.

 

If you are shooting Raw the colour profile in camera is somewhat irrelevant, it just sets the starting point when you open in your Raw processor.  Of course shooting JPEGs are a  different story and profile in camera is important.

 

The only way to remove greens though is through the tint adjustment on WB - the starting point you get will certainly vary with the camera you are using and the colour profile you set but changing the shutter speed only makes it lighter or darker.  The point of the images I posted previously was to show that the water colour does not change with shutter speed only the brightness.  Certainly increasing your shutter speed can improve the look of your image by darkening the background providing more contrast.

 

A lot of this is going to vary with how your camera deals with WB.   Some cameras if they know a flash is attached will set to a constant value others will adjust WB based upon the pre-flash, my OM-1 seems to produce images with around 5900-6100 K WB setting at least in Sydney waters.

 

I have found my best shots seem to come from ones that are minimally processed.   Just a quick tweak of levels/curves and WB adjustment.

 

 

[Chris Ross]

Here's an actual example, this shot was taken in PNG at Walindi resort.  First I have the as taken shot, only sharpening has been done, here it is in Adobe RGB profile - it should look fine as long as you use a colour profile aware browser:

 

Unprocessed in Adobe RGB

 

and here it is sRGB with blues tweaked a little  you can see the cyans are suffering:

 

Unprocessed in sRGB

 

You can see in the unprocessed image that the subject is rendered quite warm as it is illuminated by 4500K light while the frame is balanced at about 5900K.

 

Next is global adjustments to colour balance and contrast , first in AdobeRGB then in sRGB,  I quite like the blue in Adobe RGB but not so keen on the sRGB version.:

 

Processed in Adobe RGB

 

Processed in sRGB

 

I've linked them from Google drive as any image posted here is processed further and for some reason when I upload them the colours go way off.  Should be able to open them in tabs to flip between.

[Chris Ross]

17 hours ago, ChrisH said:

 

Yes indeed, when I used Olympus back then I was never satisfied with my blues. Even in post processing I was not getting the color/rendering I wanted. After I switched to Nikon, the blues were much "better" or should I say more to my taste. The difference was very notable. And switching to warmer color temperature strobes did get me a little more to my desired rendering of blue. But the difference between the Olympus and the Nikon was much more noticeable than switching to warmer strobes.

 

Also, what I forgot: Nikon has different AWB settings! And after switching from my D810 to my Z8 I had to experiment with the different AWB settings to get the results I wanted, as the newer sensor and processor rendered the colors (very) different! I now use the A1 setting, which is a little warmer than the standard setting, but not as warm as the A2 setting. I don't know how that translates to Canon/Sony or other manufactures.

So there are a lot of variables in those comparisons. 

 

Maybe I should try to just manual WB to the color of my strobes. I just didn't feel a need for it, as I am getting my "blues" the way I like them with my settings/equipment. But It would be a nice experiment.

 

Also: the desired "blue" is a personal preference and everybody has a different taste of what the "blue" should look like.

 

I only shoot RAW, so I don't have any jpg. My picture setting is "Standard" in the D810 and Z8 but that will only affect the rendered jpg file as far as I understand. So I don't know what translates to the Canon "Landscape" format? Or does it affect color rendering within the RAW file? At least for Nikon, I don't think so?

The colour temperature or WB in camera only impacts the starting point for the the RAW file and impacts how it looks when you first open the file as I understand things and in theory you can adjust the WB in post to get to any of the settings.   As I understand things in lightroom, adobe standard, landscape etc are presets which apply a standard adjustment to the file and again are a starting point.  Colour space such as AdobeRGB or sRGB when set in camera is also a starting point it sets the range of colours the raw converter can map to from your RAW data. 

 

The other thing all these in camera settings are used for is to make the in camera JPEG which is used to display the image.  RAW processing can get around all of this, however it does help if you are trying to check for clipping in your file for example.  With the wrong settings the 8 bit in camera JPG will clip before the RAW file clips and give you misleading information when adjusting your settings.

[Adventurer]

On 1/12/2025 at 9:10 PM, ChrisH said:

Ah, now I got it! my bad! I thought you meant the profile in the camera (used for the jpgs), because you refered to Canon and Landscape.

Don‘t get me wrong (Camera/RAW)Profiles (Portrait,Landscape,Neutral,Standard, Adobe Landscape etc) + ColorProfiles (AdobeRGB, sRGB) are to a large amount available in both, camera and raw converter. So with your phrase above I now struggle to understand if you refer to ColorProfiles or (Camera/RAW)Profiles.

 

The fact that (Camera/RAW)Profiles also heavily influence color balance does not make it easier for everyone to communicate about this 🤭🤣.

 

@Chris Ross the fact that you shoot OM-1 explains a lot. Color science varies hugely among camera brands and even models in some cases. But if you get exposure right you will also be able to shift between green and blue background without touching white balance. I stay with that advice and experience on many different brands I had to shoot over the years. Give it a 2nd try and watch that you do not underexposure too heavily, otherwise you will not notice the effect.

 

@ChrisH let’s come back to warm strobes or gels topic. Mr. Ross pointed out that sometimes he might not be close enough with his Z240s. This is an important factor. I see with you that you are mainly mastering the fisheye lense which usually gets you ultra close! In this case I would subscribe to your algorithm. The warm color temp of the strobes will definitely hit the foreground and also use the warm spectrum.

 

But now let’s imagine you have to be more far away and will use a more tele end lens, such as 17-55 or 14-35. You want to shoot it on the zoomed in end of wide angle underwater photography. This is not uncommon when shooting portraits of mid sized pelagics such as sharks or dolphins or shy reef sharks with strobes. There the warm color in the foreground will be quickly absorbed and have no use, because you are simply not close enough.

 

Same applies when you do not have sufficient stuff to fill the frame in the foreground.

 

In that scenario I would opt in on the cooler strobes and try to avoid diffusers, as I want the maximum energy of the strobes to penetrate the water column as far as possible. Cool color temp of the strobes spectrum will travel more far than the reddish parts emitted or filtered.

 

There is a second thread going on right now where that concept is discussed and exaggerated by even adding cooling filters to video lights or strobes. This is also the reason why Backscatter offers blue Diffusors for there HF-1 strobe.

 

However if you want maximum energy penetration through the water column then cool native color temp strobe, without any diffusors or filters is the way to go.

Edited 5 hours ago by Adventurer