What exposure settings are you using for cave diving photographs? I found that I was having to shoot at ISO 600, 1/60 sec, f/3.5 and strobes on manual/full power.
Inon-Z240 strobes (two) at full power
No remote slave - yet
I was unhappy with shooting at 1/60 and f/3.5, either too much blur or not enough depth of field. What exposure settings are you using?
Do I need to shoot at a faster ISO, or do I need to drop more cash on some slave strobes?
In my experience ISO has the most effect, I use something between 100-400 and find I generally like the results from the faster end, but when visibility or size of the space are a factor I have to make changes. I use f/3.5 (same lens as you) and I find that shutter speed makes little difference on the cave itself but sometimes there can be other reasons for adjusting. I use 1/125 or 1/250 when outside of ambient light areas most of the time. I sometimes look at the histogram but find it only a slight guide when setting up as it tends to left unless the cave is bright and highly reflective. I find I don't mess with settings on the camera at all in between shots unless I am seeing some sort of a problem, but I adjust the settings on my on-board strobes for almost every shot.
As others have mentioned something seems off. Is that image you posted heavily cropped? I don't have any experience with those particular Inon's but if I used similar settings and got that close my shot would be blown out. That is a rather dark walled area that you showed and there is the black passage behind the diver would skew the histogram
Slave strobes help a ton, but it does give a different effect.
I'm glad to see some cave related talk here. I've found very little help out there on the topic and would love to learn more and share. If anyone wants to do some NW Florida cave photography give me shout. I'm up for spending dives just figuring out lighting, settings, or messing with slaves. Best way to learn is to get in the water and try out different things.
Here's some photos I've uploaded to my gallery on www.cavediver.net: