Archived posting to the Leica Users Group, 2011/11/11
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Adam Bridge wrote: >>> One of my favorite lenses is the Leica 100mm APO that lives on my Canon 1Ds Mk II. Up close it's fabulous, but at infinity all the great sharpness is gone, there's just not crisp focus. Is this a problem with the adapter I'm using to mount it on the EOS' mount? Or might it be an issue with the lens itself? And how do I tell which it might be? <<< Since this lens has a hard stop at infinity (unlike some APO lenses that focus to infinity and beyond) an adapter that's a tiny bit too thick could keep the lens from reaching true infinity focus. I'd try a series of photos under controlled conditions (MLU, tripod, timer or cable release, no heat waves) at varying distances. If the adapter's the problem you should see very sharp photos at all distances short of infinity. If the lens has a problem I'd expect to see a gradual fall-off of sharpness as the focus distance approaches infinity. Or find someone nearby with a 100 APO and do some A/B comparisons. Doug Herr Birdman of Sacramento http://www.wildlightphoto.com