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by enricosavazzi
Sun Jan 03, 2010 2:26 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: DOF and pupil ratio
Replies: 15
Views: 4285

When the math is all gotten correct (no easy task!), the result that you get by computing from NA directly is the same as the result that you get by carrying P all through the calculations. The DOF of an ELWD 20X NA 0.4 objective is the same as any other 20X NA 0.4 objective. --Rik Thanks for the c...
by enricosavazzi
Sun Jan 03, 2010 6:23 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: DOF and pupil ratio
Replies: 15
Views: 4285

Re: DOF and pupil ratio

> Did you intend to write 2.9µm and 5.5µm for the DOF values of the Nikon M Plan objective? Yes, thank you for pointing out the mistake. Easy to miss a zero while converting from mm. I corrected the original post accordingly. > On the other hand, is it possible that the designated numerical aperture...
by enricosavazzi
Sun Jan 03, 2010 3:13 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: DOF and pupil ratio
Replies: 15
Views: 4285

DOF and pupil ratio

In a recent thread in this forum, it was shown (once more) that focal length and sensor size do not affect DOF, at least within the range of magnifications used in macrophotography and photomacrography and when the final images are observed at the same absolute size. Well done. Virtually all the DOF...
by enricosavazzi
Sun Nov 22, 2009 9:14 am
Forum: Equipment Discussions
Topic: 'repro' lens question
Replies: 8
Views: 4535

Re: 'repro' lens question

... Is that an omission or something would go wonky on it at a different mag? The resolution ought to support 3x or more for a 12MP FX sensor. Or will it be compromised at a different working distance? In that case it might be better on micro 4/3. It throws a somewhat larger image circle than 35mm,...