 Posted: Tue Oct 06, 2020 4:46 pm Post subject: |
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Ray Parkhurst wrote:
| jamaeolus wrote: |
| just snagged a 40mm 2.8 SK apo componon HM. I read somehwere that reversed it can go down to 12 to 1 ? Does that sound right? |
An f2.8 lens will have effective aperture of EA36 at 12:1 and thus will obscure the smallest details. Commonly-available 10x / 0.25 microscope objectives can be used at 12:1 and would have EA24, so the tradeoffs vs the 10x objective would be improved coverage as well as depth of field.
Now, the 40HM is probably not aperture-limited at f2.8, requiring that you stop-down a bit to improve image quality, further degrading detail resolution while improving depth of field.
_________________
...See my Numismatic Photography website at: http://www.macrocoins.com
...Primary Studio Cameras: Sony A7Rm4 and Canon HRT2i
...Go-To studio lenses: Nikon 95mm and 105mm Printing-Nikkors; Schneider 85mm Macro-Varon; Nikon 5x, 10x, and 20x Measuring Microscope Objectives; Mitutoyo BD Plan Apo 50x Microscope Objective
...My Go-To Walkaround Lenses: Laowa 60mm Super Macro; Nikon 28-105D (in manual mode for macro); |
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