Hi, guys
first post here, but quite a long time I have been benefiting from reading you. So many thanks!!!
I have red quite a lot about filters in the forum, but always in the context of dedicated photography (one subject-one dive) and assuming some fiddling later in photoshop. My question is regarding use of filters on competition, where there is no chance of post-processing and time and changing lenses is severely restricted.
I do have a real example: in my next competition we do have to shot this in a 2 hour lapse (that would include a tank dive and snorkeling):
- 1 ambient photo (with model)
- 1 black and white photo (with or w/o model)
- 1 split shot with model
- 1 ambient photo with model snorkeling (and we are "invited" to the model using and 2*2 meter silk textil)
Not easy, indeed, and even more difficult when having to chose lenses (I own Nikon 10,5, 12-24, 17-55 and Tokina 10-17)
I might go with the 10-17 for ambient, snorkeling and B/W and 12-24 plus split shot filter (half +3 diopter half -2 stops) for the split, so I only change lenses once. I might even try the split with the 10-17 and not changing at all (here you have why I have said bye to my trusty 10,5 
).
The think I am concerned about is that my D200 seems not to handle B/W well and there is no way I can upload a custom curve for it. In past contest I have seen that while Canon records pure black, pure white and the shades of grey, Nikon seem to grab only greys and photos look awfully muddy (I first thought it was related with how I do meter and read about Ansel´s theories, but now I do not think is a metering problem).
Apparently, Canon users can load a "digital" yellow filter to enhance their photos, so I wonder whether to use one in my lenses (not common in digital with the B&W conversion capabilities of Photoshop, but necessary in this case). I guess so, but then we have the versatility problem, I would have to stick with it the rest of the dive. I have thought of the following solutions and I would like to know some ideas from you:
1. -Yellow filter in the flashes (2 Seacam digiflash 250 or 2 Inons Z220): This would allow me to take the filters off and continue making color photos. I am not sure: maybe would give black and white in the nearest focused areas but what would happen to the blue?. OTOH, blue should be gray, so maybe this is OK.
2. -I red of someone using kind of gel filter outside the dome to limit light input in split shots. I doubt I can do something similar with any yellow material 
. BTW, Dr. Mustard, do you carry magic filters for the Seacam Superdome surface? 
3. -Using the yellow filter in the lense for the B/W and later white-balancing so I can keep shooting in color. The camera should handle this, I guess. This would be the case also If I finally made the snorkeling photo with a magic filter, as I am thinking of (people is not using them in competition here, so it might push me to the edge -hope they do not read this- 
). I might white balancing and then making the split shot. Or not? This would be ideal since I will shoot both of them by the shore.
4.- Would the magic filter boost the contrast in B/W so I can take all the photos only with this and no changing at all? This would be of course the best solution. In this scenario I might even think of one more change to use the split filter, but that would depend on how sunny the day is and composition regarding the submerged scene.
Hope not to have extended myself too way long with the post.
Thank you!
