DTan said:
Very detailed explanation by waisj. helps to cement better the knowledge.
Kthan, do u get correct exposure even for white subjects or for subjects on white sandy floor? or that accounts for the 0.1%?
I had a terrible experience with TTL this recent trip (cuz KS use 2 strobe on macro) tho but i have not much doubt it works usually. cuz otherwise i wouldn't know how to take. Not experienced enough.
Kthan, u will use only 1 strobe (TTL) for macro is that true? And 2 strobes for wides (manual)? If so, how to calculate distance and f-stop based on 2 strobe usage cuz the guides provided are only for 1 strobe.
am i confusing?
i see someone is tempted to go towards 5050... no more canon for u???
as i mentioned, unless i can syn cord both strobes, i believe I cannot get real TTL with one strobe syned and one on slave. (but I may be wrong!) Going on this train of thought, I reckon my dual strobe setup will result in overexposure. Hence I always use one strobe for macro.
besides, i wanna setup my strobe as near to subject as possible for macro and TTL. With one strobe, i can detach and handheld it with the S&S setup. with 2 strobes and w/o ULCS arms, i cannot do that. and this is the main reason. so thank god i stick to my one strobe setup for macro.
i aim the strobe to hit the top of the subject if on sandy bottom, eliminating a direct hit on the white sand. I seldom use diffuser, although i think i should. REmember i always use film, which has a greater latitude for error. Photos always turned out well, although I cannot tell if it is due to adjustment done by the processing lab. u can check the behind of the prints for that, but i didn't know then and I never went back to those photos since i switched to digital.
As I mentioned to u on the LOB, for CFWA, i TTL the subject and use my own set of combi (f-stop + 1/100 speed) to "meter" the blue. it works sometimes, that's why i said TTL is not for use on WA becos it is not 99.9% :bsmilie: .
Subject could be properly exposed but the blue is a guesstimate. But i do like what I see with the dual as compared to single strobe for WA. Bought the DX90 after flooding my DS-50 for a bali trip and frankly i use the dual setup only once on my S&S. Again , don't forget the part about me using film and the lab adjustment. U will definitely learn more using slides, but my argument is that since the developing is not onsite, you won't know your mistakes till u have finished your dive vacation, and it will prob be a few months before u get to shoot u/w again. i would rather get a higher % of keepers by using film becos of the exposure lattitude it accords.....
the second use was a disaster becos I use a ISO 400 and my camera only accepts ISO 100.
For full manual use of the strobes:
Guide Number / Subject distance = f-stop (with ISO 100)
GN can be in feet or m. do a search on yahoo and you will find something useful.
Eric