Focus peaking v. magnification

Old Listener wrote:

Tom Caldwell wrote:

(Ricoh's) Mode2 is unlike all others as the whole outline of an object is sharpened when in focus. the sharpening increases as focus improves until it pops and the exact point of focus can be easily seen screen wide. The sharp line "pattern" is very easy to see and detect and therefore makes "in focus" instant and very certain.

However it is a shock to those who like to see a "perfect image" in focus when it reaches "most perfect". Both are simply different preferred ways of working. For some the perfect-focus image and framing are everything. I like framing best and am happy to use a "machine" to tell me that I have focus nailed. Not much different from using auto focus in its own way. Except that you have to soft press the shutter to see "composition mode".

I don't understand how Mode 2 would work for closeup photos on small objects. It is common to have so little depth of field that the entire object won't be in perfect focus.

I don't have any external lens that will go extremely close but I have the Ricoh 50mm f2.5 macro module which does focus to about 50mm and mode2 is very effective with it. I just tried it on a computer keyboard using auto-focus as the Ricoh focus peaking in both MF and AF modes as the user might desire. But if I just screw the lens out to its maximum and move it backwards and forwards the point of focus s easily visible.

Of course extreme macro with very small dof would provide a very limited distance to show correct focus but as the focus peaking works on contrast detect even a very small dof will still have contrast as long as the subject matter has a surface with any edges. In fact with a very small dof the point of focus must in fact be even more accurate. Now that you have me going I will have to try this with some extension tubes to get true minimal close-up.

Hmm - an old Sun Macro Zoom (normally 280mm closest focus) and a whole nest of extension tubes still only focuses to about 45mm but it still shows point of focus very clearly. But I have no doubt if it would go closer then the focus peaking would still work as long as there was some contrast in the subject matter.