05-08-2011, 09:56 PM
[quote name='Vieux loup' timestamp='1304885872' post='8136']
Thanks again Rainer for bringing me back on the straight and narrow <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/smile.gif' class='bbc_emoticon' alt='
' /> ! What does it mean in practical terms to loose focus to infinity. You focus up to a certain distance I guess and then you loose the focusing ability? Are there any rules about how far out you loose the focusing?<img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/unsure.gif' class='bbc_emoticon' alt=':unsure:' />
[/quote]
Here is one calculator to give an indication. If you're just looking at effect of extension on infinity focus, then just put in the lens focal length, set D to zero, and add extension as needed.
I'm still working on a FD 50mm f/1.2 non-L to EOS conversion. Replacing the bit around the mount section will allow infinity focus in this case, but metalwork was never my strong point...
Thanks again Rainer for bringing me back on the straight and narrow <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/smile.gif' class='bbc_emoticon' alt='
' /> ! What does it mean in practical terms to loose focus to infinity. You focus up to a certain distance I guess and then you loose the focusing ability? Are there any rules about how far out you loose the focusing?<img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/unsure.gif' class='bbc_emoticon' alt=':unsure:' />[/quote]
Here is one calculator to give an indication. If you're just looking at effect of extension on infinity focus, then just put in the lens focal length, set D to zero, and add extension as needed.
I'm still working on a FD 50mm f/1.2 non-L to EOS conversion. Replacing the bit around the mount section will allow infinity focus in this case, but metalwork was never my strong point...
<a class="bbc_url" href="http://snowporing.deviantart.com/">dA</a> Canon 7D2, 7D, 5D2, 600D, 450D, 300D IR modified, 1D, EF-S 10-18, 15-85, EF 35/2, 85/1.8, 135/2, 70-300L, 100-400L, MP-E65, Zeiss 2/50, Sigma 150 macro, 120-300/2.8, Samyang 8mm fisheye, Olympus E-P1, Panasonic 20/1.7, Sony HX9V, Fuji X100.