11-22-2010, 05:45 PM
Roughly speaking, shorter focal length lenses will have more of a "problem" than longer ones. You can try this calculator for an indication. Zero the close up lens dioptre value and plug in just the focal length and extension. The rest don't matter if you're not looking at minimum focus. As example, if you have 2mm extension on 50mm lens, you're down to 1.3m! But 2mm extension at 300mm works out to 45m.
Otherwise, learn to love macro <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='
' />
Otherwise, learn to love macro <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='
' />
<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.