What's the best way to set manual white balance for UW photos

[DazedAndConfuzed]

Interesting with the fins.

I pointed it at the sun a few times this past trip. given the deeper one is, the more blue the sun's color is (Sun is roughly white in color temp). Of course, that doesn't differentiate between taking pix of subject 10ft vs 30ft away. But it works kind of well.

 

[farsidefan1]

Would a red filter add red back into the equation? So you would have some red to work with in photoshop elements?

 

[DazedAndConfuzed]

I guess it would add some red back into a jpeg image, since when shooting uncorrected image into jpg, what little amount of red there is might get discarded. Using red filter will be similar to setting WB while underwater.

 

[spoolin01]

Would a red filter add red back into the equation? So you would have some red to work with in photoshop elements?

There was a recent thread on that topic http://www.scubaboard.com/forums/underwater-photography/382619-raw-red-filters-wb-oh-my.html, and I think also another link there to an earlier thread. Opinions are somewhat mixed but from the 'who needs a red filter' advocates, it's hard to distinguish 'it does nothing' from 'it does nothing I care about'.

It seems to me that WB and red filter are both ways of better balancing the skewed U/W color distribution of a photo, but they differ importantly in how they get that done. No doubt there are reasons to prefer one or the other, at different times.

 

[DevonDiver]

Photoshop is very effective for editing color, wb and other aspects of underwater photographs. That said, the more information that PS has to work with will have a direct impact on the quality of the post-processed photograph. Manual wb, adding light sources, shooting RAW, choosing appropriate angles to maximise ambient light on the subject etc etc will enable more effective corrections when you get the pic onto your PC.

Here's my blog article, that deals with simple PS editing of underwater photographs:

http://www.scubaboard.com/forums/blogs/devondiver/30-5-minute-photoshop-edit-underwater-photographers.html

 

[fab50diver]

Love all the suggestions! I simply use a small dive slate to set my WB at depth.

 

[TomReynolds]

First a 2GB card will work. You may need to reformat it. Anything bigger will not.

Second, shoot in RAW then look at the R,G,B channels in the Raw converter. This is what the camera sees, period. White balance only changes the balence between the channels. The way to add red is to dump pixels into the red channel from other channels. There are multiple tutorials on how to do this. You can then manipulate the white balence in RAW to, hopefully, get what you want. Possibly your convert to CMYK then convert back process is doing something of the same but this is the straightforward way to do it.

Tom

 

[DazedAndConfuzed]

I got a 2GB to work on my recent trip.

I used the CMYK process because there were not enough red in JPEG image to work with.

Doing UW WB seems to be better, especially if saving to JPEG because it has a higher red content when saving, unlike saving with auto-WB, where the little amount of red seems to get discarded as noise during compression.