I tested the backfocus of the Maxxum 7D. Links below. For the 100mm lens, all seems well. For the 50mm lens, it seems to focus camera side of the target. Any ideas? Cheers, Alan Tested: 100 f/2.8 macro against two targets on an oblique 50 f/1.7 against one target on an oblique. --Max7D + lenses above --Tripiod --cable release --mirror lockup --angle finder at 2X for manual focus --A/S off --ambient light 100mm results: perfect 50mm results: appears to focus slightly close to the camera v. target (2 samples of each from bunch follow). 100mm f/2.8: http://www.aliasimages.com/images/KM7D/BF/PICT0710a.JPG http://www.aliasimages.com/images/KM7D/BF/PICT0721a.jpg 50mm f/1.7: http://www.aliasimages.com/images/KM7D/BF/PICT0717b.JPG http://www.aliasimages.com/images/KM7D/BF/PICT0718b.jpg note: on the paper target, the focus point is marked with bars with ambient light from window. ruler target, the focus point is the 15 cm line with ambient light from softbox on farside of ruler. Comments on why the 100mm shows in-focus at the selected focus point and the 50mm does not? Cheers, Alan
I read an article that showed that the cover glass on the sensor made that some lenses did not focus correctly. Non digital lenses are corrected for having air between the lens and the film. /Roland
Very odd. Do you have this article online? Or what magazine was it? In any case, none of my lenses are "digital". Cheers, Alan.
Found it! Here it is - in German. http://www.colorfoto.de/sixcms/media.php/258/0904Autofokus_cofo.pdf Lenses seldom are /Roland
