Can I use colored gels for underwater photography

[paul_durand1]

Hi all,

I have a canon P&S with an underwater housing and attachable diffuser. I am interested in taking photos when I

dive, but am a touch worried about color loss at depth (i.e. loss of reds and greens). Will a gel work on the diffuser to

compensate for the color loss and ultimately an unbalanced light from the flash or is it a waste of time? I could

correct in PS, but would like to have as balanced a picture as possible since the resulting image is a jpeg. If it is

worth the effort, what correction gel could someone recommend?

Thanks for any advice,

 

To the moderator,

I hope that I am in the right forum; if not, could you please relocate me to the correct one? Thanks!

[mark u]

Flash will produce a daylight colour balance with no need for any filtration (use flash colour balance, or RAW and set afterwards if your camera offers this). The disadvantage is that flash will suffer from inverse square falloff, which means that either the background may be dark if it is distant, or it will have a strongly blue shifted spectrum. The disadvantage with on camera flash is that it will light up brightly any particulate matter in the water close to the lens creating out of focus "orbs" that can spoil you images. By using an off camera strobe you can secure more even and more powerful illumination while avoiding "orbs". If you don't use any flash then you will suffer from attenuation of the redder end of the spectrum in the illuminating daylight. You could try to correct for this by using a red or orange filter over the lens, but it will result in much longer exposures in what is already dimmer light - and getting the correct white balance doing this may be a real challenge. You may be better to simply adjust white balance from unfiltered shots. Other than for "scientific" purposes, you will find that it can look more natural not to try to create a full daylight white balance when shooting underwater.

[tim_mulholland]

I'm not certain which Canon P&S you're using (I've seen some friends use a G9 for similar purposes), but I think that the previous answer was a good one. First, I'm not certain how you'd keep the gel on the lens. Second, before trying a gel, I'd suggest that you see what happens when you manipulate the white balance. Try shooting in RAW, and then work with the white balance in your Canon software or PS. Additionally, you also could try some other types of color correction in PS.

 

And, unless you're in exceptionally clear water, the flash backscatter could be difficult on your image, since the flash sits so close to the lens; that's why the use of an off-camera strobe was suggested (but I don't know whether such a thing might work for a Canon P&S...).

 

Good luck,

 

Tim!

[paul_durand1]

Thanks Mark and Tim,

I will give the WB a try, but as I have a Canon SD 1000, I do not have the option to shoot in RAW; only JPEG. I can however, clean up in PS.

[2Oceans]

The Magic filter site may help you out. Kodak Wratten filters like a CC30R work pretty well but probably not as well and are cheaper.

 

Either way filters do work. Strobes only carry 3-5 feet at best so for wreck and large animals they are not as useful for large areas you want to affect.

 

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

 

http://www.magic-filters.com/download/UWP26a.pdf

 

http://wetpixel.com/i.php/full/magic-filter-review/

 

Good hunting,

vr

Andy

[alastairjamieson]

<p>Hi,</p>

 

<p>It is common to use warming cards to take a white balance for underwater video productions. If your still digital camera has a manual white balance function, you can use the same method. 'Warming cards' are bluish coloured, so when a custom white balance is taken, it causes the camera to record warmer colours than if an actual white card was used. The same method can be used out of water to get warmer colour results too.</p>

<p>There's a very informative description of how the method works on this <a href="http://www.kenstone.net/fcp_homepage/white_cards_douglas.html" target="_blank">product review page</a>.</p>

 

<p>I'm not certain, but I think there's a problem with the gel filter idea because the filters effectively remove parts of the colour spectrum of the light that passes through them. Underwater, you've already lost some colour because of the filtering effect of the water, so you don't want to lose any more!</p>

[steve_levine]

With a film camera the color temp difference is too extreme underwater to be corrected with a filter. After 15 feet deep,

everything turns blue/green and flash is the only way to fix it.

[2Oceans]

Paul,

Flash has its limitations as do gels but for point and shoot cameras the gels such as Magic Filter or Wratten CC30R help to restore the warmer colors that are lost after the sea water has filtered color out. This helps in the absence of post processing. Folks even buy scuba masks that have a reddish filter to restore color lost at 30 feet. This technique is over 40 years old and I have a set of Nikonos filters from that film era. I personally use the Wratten on occasion and have 5 powerful strobes that carry light not much more than 5 feet underwater despite their cumbersome size to transport and great expense. A filter to restore color makes sense for seascape images. The wetpixel.com site probably has more information on color filtration underwater for digital cameras of all types than any forum around. There is a specific forum for PS cameras at that site. Incidentally I shoot with a housed D2X but have seen underwater images from a point and shoot that are amazing. I don't know Alex Mustard who is one of the folks that developed the Magic filters for both DSLRs and PSW cameras but apparently he is very well thought of as a photographic innovator both artistically and technically in the underwater photography world and worthy of consideration. If you are shooting close up or macro you will want artificial light but if you are interested in seascapes where strobe light can't go I would recommend trying a gel. The price of the gel is an order of magnitude less than the cheapest underwater strobe and you might be very happy with the results. Good luck. vr Andy