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Lens extention for close focusing

G

Guest

does anyone know whether or not any lens extention for close up for manual contax SLR available in the market? I know that there were 7.5mm 13mm and 26mm available before, but couldn't locate where to find them....any idea?

Ben
 
G

Guest

Has anyone tried the 7.5mm extension tube with a 28mm lens? If it works, what kind of ratios do you get and at what distances? Thanks!

Lyn
 
G

Guest

Hello Lyn,

haven't got the 28 mm, but the 7.5 mm Ring. A simple calculation gives the following for the 28 mm:

Distance with ring, lens set to infinity: 132,53 mm
Distance with ring, lens set to 0,25 m: 99,07 mm
Magnification ratio from 1:3,73 to 1: 2,53

Matthias
 
G

Guest

> The distances provided by Matthias are the distances between the subject and principal plane. The distance between the subject and the first lense element is (appr.) 96 mm (if the lense is set to infinity). It's so close that the lense may block the light iluminating the subject.
 
G

Guest

Ooops, forgot to mention that. Thanks for the hint Sergiy!

Matthias
 
G

Guest

Thanks for the help, guys. Sorry I'm so slow; I rarely have time to check the site. I especially appreciate the info. on light blockage. Of course, it makes sense when I think about it.

Lyn
 
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