Macro NUB with DOF questions...

[Xirxes23]

So i just recently purchased the tamron 90mm macro for my Canon EOS digital, sweet lens, but im having some dificulty getting the kind of DOF i am looking for in my macros...

I have read every DOF tutorial on this seciton of forum a few times, and seem to understand it, but have trouble putting it into action. I can focus on the section i am interested in... but i get a DOF of maybe...2-3cm? is that right for a working distance of about 6-9 inches? I am needing a DOF of maybe...5-6cm's for the shots im taking now, how do i get it?

I have tried every fstop from 2.8 up to 12 that will give me a shutter speed of 1/15 or less without the flash (i love tank lighting, and have only on body-flash aka. sucky)

right now im only shooting the blue legs/turbosnails/emerald crabs i have in tank, but soon it will be go time for zoos, clams, anenome's and the rest of the gang...

Any personallized advice for me?

Shots today i will post the best of tomorrow... were shot at ISO 400, Fstops 2.8-8.0 usually, with shot speeds 1/15 or less on a tripod, tank lighting is full spectrum T5 6 bulbs, white balance taken of aragonite in tank.

 

[Xirxes23]

just a note...**jealousy to ensue** he has my same lens... i want this kind of DOF...
good tamron macro

 

[gregr]

The closer the lens is to the subject the lesser the depth of field- so when you're going for those super close close-ups very small apertures are needed to get decent depth of field. That usually means one of two things- a tripod or a flash. If you're shooting something that is moving [at all] a flash is your best bet. And using a flash will be difficult until you get a speedlight to put in the hotshoe.
I'd recommend practicing on stationary subjects for a bit. Do you have a tripod? If you choose a subject that is perfectly still give these settings a try and see how the pics look:
iso 100
f16 (experiment on up to f32 even, just for kicks)
2 second delay [self-timer]
Remember to shoot squarely into the tank too.
Greg

 

[jwedehase]

Unfortunately, that's the way the cookie crumbles. The shorter the working distance, the shorter the DOF. Obviously, you could bump the aperture up to f/22 or whatever, but you really sacrifice shutter speeds. This is fine for stationary objects like hard corals, but not so hot for fish and anything that might actually move.

I don't like shooting with an ISO higher than 400, either, but sometimes it's an acceptable sacrifice. When I *HAD TO* get a clear shot of an infection on one of my fish, I actually shot at ISO 1600, though quality was obviously sacrificed.

 

[Xirxes23]

heres some initial attempts...
Emerald crab

Adjusted white balance, diff Emerald

Turbo

Blueleg crab

And here are the tests of f32 tripod tests, (dirty glass), please forgive just shots of live/base rock, is all i have that is stationaryright now, lol

Any advise on lighting? what kind of flash do you recommend for the EOS digital for tank shots?

 

[Xirxes23]

bump....

no input?

 

[gregr]

I think the best flash for aquarium photography on a Canon camera is the twin macro flash unit.