On Wed, 28 Nov 2007 01:34:57 +0000, ZenDiver <spicedhamme@[EMAIL PROTECTED]
> wrote:
>self wrote:
>> How do I duplicate an underwater photo of a color wheel?
>>
>>
>> I want to try to correct underwater photos that I took to reflect the
>> fact that some colors do not show correctly at depth. I took a color
>> wheel to a depth of 50 feet and photographed it using natural light. [
I
>> did not use a flash.] I then took the resulting photo of the color
wheel
>> and tried to use Photoshop to alter the color so that it would match
the
>> original.
>> I can't seem to get the photo of the red sector to look even remotely
>> like the red original. I do not know much about Photoshop, is my
>> approach wrong or did I overestimate the ability of Photoshop to
restore
>> the original colors?
>>
>
>The problem is that there is an uneven loss of the colour spectrum with
>the red end fading first and so on until everything is in shades of
>blue. What you need to do is rebuild the red channel in the photo, this
>can be a long and complex process. Here is a link to a tutorial from
>the Digital Diver Network (http://www.digitaldiver.net)
>http://www.digitaldiver.net/lib_docs/color_cast.pdf
>
>Depending on which camera you are using there may be other ways for you
>to improve the colour rendition of your photos. If you can set the
>white-balance manually or are able to shoot RAW then you are in luck,
>otherwise filters are your best bet with ambient light.
>
>jon
Interesting. I hadn't considered that the lost reds could be added back
in, not
having done much underwater photography in the past and nothing more than
max
snorkeling depths (25-30 ft.). The deeper you go the less time to frame a
shot!
But then with all the color channels available for tweaking I see how it
could
be done. Not perfectly but at least salvageable. Not too different than
how to
make moonlit photos look like more like they were originally taken in
moonlight.
When properly exposed they look little different than taken in daytime,
totally
losing the effect you had intended to capture. My fix, desatureate reds,
reduce
brightness, increase contrast.
While you can't perfectly recreate what was lost to the water, the
spectrum
section missing or greatly subdued, I see now that you can at least
emulate it
somewhat. Now I know how to make those shallow depth reef photos look like
I was
down at 200' while snorkeling. Reverse the process. :)
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