Sun 08-Jul-12 11:07 AM | edited Sun 08-Jul-12 11:08 AM by elec164
> not filling the frame. The extra subject distance might get you a >bit more DOF, then crop the photo for desired image size.
Unfortunately that doesn't work as you suggest. DOF is an illusion based upon the limited acuity of human vision. It's dependent upon the amount of enlargement of the capture and the viewing distance of the observer. Yes not filling the fame by increasing the focus distance will gain some DOF. But cropping then enlarging negates the gain creating a wash at that point.
>Have also used a ringlight for some serious small apertures, >however the diffraction is an issue.
Yes diffraction is real, but in my opinion often over stated and fretted about. Also by using deconvolution the affects of diffraction can be mitigated. For example look at Hendrik's examples. If you look at the narrow DOF example you can see where the plane of focus is with no diffraction affects (assuming that's a full frame capture). Now look at the same area in the wider DOF capture. Yeah there is a small loss of fine detail, but with proper PP sharpening that loss will be transparent to the viewer unless its a known subject that the views could mental compare to. That's why when I'm shooting macros, I'm willing to accept a small loss due to diffraction because the gain in DOF adds more to the image than the usually undetectable loss of fine detail.