Micro focusing technique

Any of the instructions for micro-focusing adjustments indicate that the focusing target be in perfect focus...
taking into consideration that your in-focus area is about half in front and half behind the subject,
would it not make more sense to set that up to back focus just a bit?

chauncey wrote in post #18117667
Any of the instructions for micro-focusing adjustments indicate that the focusing target be in perfect focus...
taking into consideration that your in-focus area is about half in front and half behind the subject,
would it not make more sense to set that up to back focus just a bit?

No I would not try to take DoF into account when setting MFA. DoF is NOT a fixed property, since it relies on final image size, as well as viewing distance. Also there is only one infinitely narrow plane of focus, as we move away from that plane the image ceases to be composed of infinitely small points, and starts to become blur circles instead. With a planar subject, which a focus test chart is, you want the plane of focus to also be exactly at the sensor to resolve maximum detail. In a 3D subject you would be very disappointed if for example you focused on the surface of the eyeball, and actually got one of the eyelashes in perfect focus.

Alan

chauncey wrote in post #18117667
taking into consideration that your in-focus area is about half in front and half behind the subject, would it not make more sense to set that up to back focus just a bit?

No because the in-focus area is only the plane of focus. Everything else is increasingly more out of focus. The area of acceptable focus/out of focus is as Al points out perceptual and is based on the final image size/viewing distance etc.

Also the area that is acceptably out of focus isn't always "about half in front and half behind the subject". At different settings it can alter from that dramatically.