Leica User Forum - View Single Post - Tech question about DOF

luigi bertolotti · 05/05/08, 08:12 AM

Yesterday night I wanted to take & post a pic of an old lens of mine (it's in the historical section... Summaron 35...) ; I was uncertain between using my favorite macro set (Tele Elmar 135 head on Visoflex) , or the quickier Summicron Dual Range: I decide for this because the subject was inclined, 3-4 cm of effective "visible depth" and I wanted a decent depth of field... but, afterthat, I was caught by a tech doubt... is it really so ? I never went in depth with the math of DOF... question is: if one achieves the SAME field of view (say, a 36 x 54 rectangle, ratio 1:2 on M8) with a 50 and a 135 lens, of course with diaphragm closed the same, is the effective depth of focus different ? I'd say yes,but, not knowing the math at the base, am not at all sure...

05/05/08, 08:12 AM	#1 (permalink)
luigi bertolotti Erfahrener Benutzer Join Date: 01/24/07 Location: Brescia Posts: 2,524	Tech question about DOF - macro environment Yesterday night I wanted to take & post a pic of an old lens of mine (it's in the historical section... Summaron 35...) ; I was uncertain between using my favorite macro set (Tele Elmar 135 head on Visoflex) , or the quickier Summicron Dual Range: I decide for this because the subject was inclined, 3-4 cm of effective "visible depth" and I wanted a decent depth of field... but, afterthat, I was caught by a tech doubt... is it really so ? I never went in depth with the math of DOF... question is: if one achieves the SAME field of view (say, a 36 x 54 rectangle, ratio 1:2 on M8) with a 50 and a 135 lens, of course with diaphragm closed the same, is the effective depth of focus different ? I'd say yes,but, not knowing the math at the base, am not at all sure...