Recommended macro settings -- D 70/70-300 Sigma APO (DOF problems)

[RandyS]

I have started experimenting with macro photography. Presently, I am using a 70-300 Sigma APO. My problem is I seem to have insufficient depth of field -- if I am shooting an insect, part of the insect may be in focus but part is not. I suspect that DOF issues necessarily are a potential problem with macro photography. Nonetheless, I seem to have trouble ensuring that all of my subject, regardless of size, is in focus. While I considered that this problem could be due, at least in part, to focusing problems, I did have my camera checked out by Nikon for back focus -- Nikon advised that they did not find any evidence of a back focus issue. Also, I generally have not noticed focusing problems, although certainly any such issues would definitely be more noticeable in macro.

Accordingly, I wonder whether the DOF is too short/shallow. To correct this, I have tried closing down the lens to increase DOF (e.g., f 18-f 22), but this has caused shutter speed problems (I typically use a tripod, but if the subject is moving, the tripod will not solve this problem.

Also, I have read that all lenses have a sweet spot generally between f 8 and f 11. I don't know what sweet spot is for 70-300 Sigma APO, but I suspect it certainly is not f 18 or higher.

I would appreciate any advice on how others deal with these issues. My questions are not truly limited to macro, either. I like to shoot butterflies using either the D 70 kit lens, or the Sigma, and I'm constantly struggling with what the proper settings should be.

Again, any advice would be greatly appreciated. Thanks.

-- Randy

[jfrancho]

Attaining a desired DOF is one of the many satisfying challenges that macro offers. I deal by using a flash, reflectors, diffusers, etc. A speedlight and off camera cord with some sort of flexible bracket will be a good start.

[RandyS]

Is there a typical aperture that you hope to use for your macro photography? I have a SB-800, which I will often use in a wireless remote mode -- I'm just trying to get some sense as to what settings I should try to achieve. Any advice would be greatly appreciated. Thanks.

-- Randy

[jfrancho]

I don't have a "set" aperture, but I do use the DOF preview, and possibly a DOF chart. Usually f/4-f/16 gives me what I want.