|Dynax 7D focusing test|
| I used the test procedure described here: http://www.photo.net/learn/focustest/.
All the tests were duplicated with my Dynax 7 loaded with Fuji Sensia 100, the film was scanned, and images from film is shown beside the images from the 7D.
|Dynax 7D - ISO 100||Dynax 7 - Sensia 100 - Scan Dual II|
|Minolta 24-105mm @ 70mm, f4.5|
|Minolta 24-105mm @ 105mm, f4.5|
|The 24-105 seem to back focus a little bit. Most noticeable at 70mm. The line is however acceptably sharp at both focal lengths.|| On film the 24-105 the situation is opposite, focus seems to be a little bit to the front. It also seems to be less obvious at the longer focal length.
(I made a small error here, and shot at 50mm and not 70mm as with the digital image.)
|Minolta 100-300mm @ 200mm, f5.6|
|Minolta 100-300mm @ 300mm, f5.6|
|The old 100-300 (non-APO, non-D) is front focusing, but the line is again quite OK.||The old 100-300 (non-APO, non-D) is front focusing on film also, but a little less obvious.|
|Minolta 50mm, f1.7|
|Slight back focus with the 50mm wide open.||Slight front focus on film with the 50mm wide open.|
|Cosina 100mm macro, f3.5|
|Cosina 100mm macro, f5.6|
|The cheap, plastic Cosina 100mm macro seem to be almost spot on. Maybe a fraction of back focusing.||Same situation on film. Looking at the 100% images I am able to see the tiniest amount of back focusing.|
| Of my four lenses two backfocus a bit, one is front focusing, and one is spot on on the 7D.
On my film 7 the two lenses which is backfocusing on the 7D is front focusing. The other two are about the same on film as on digital, the slightly better results on the film camera may very well be caused by the larger DOF on the film camera compared to the 7D due to the crop factor.
All in all the results from both my cameras are pretty equal, and I don't think any of the lenses show unacceptable AF performance on any of the cameras. I think both my 7 and 7D is focusing well within spec, and I will now stop taking pictures of lines on paper and go outside and do som real photography :)
|All images Copyright (C) 2004 - Torstein Vee Haukvik - firstname.lastname@example.org|