Schneider-Kreuznach 90mm f/4.5 Makro-Symmar (Nikon F-mount)

[pluton]

John, Can a manual focus lens 'backfocus?'

[JohnBrew]

I'm probably not expert enough to say. If you focus at a specific point and the camera gives you focus confirmation, make the image, and view on importing and something in the bg is all that is in focus I would call that a back focus problem. Perhaps it was a problem with that specific copy of the lens. I never had that problem with any other lens on my D700. I wish I had saved one of the images for demonstration purposes, but I didn't. I didn't have a problem with normal landscapes, just closer subjects.

[bobfriedman]

if it was the "green dot" focus confirm... i would say the camera was back focusing

[simsurace]

I'm probably not expert enough to say. If you focus at a specific point and the camera gives you focus confirmation, make the image, and view on importing and something in the bg is all that is in focus I would call that a back focus problem. Perhaps it was a problem with that specific copy of the lens. I never had that problem with any other lens on my D700. I wish I had saved one of the images for demonstration purposes, but I didn't. I didn't have a problem with normal landscapes, just closer subjects.

That is due to a mirror misalignment. Theoretically, they can be aligned by setting two screws in the mirror box. The optical path lengths to AF module and ground glass have to match.

[KarlMera]

if it was the "green dot" focus confirm... i would say the camera was back focusing

Yes, the camera, or the person behind the camera, not the 4,5/90mm.

[Erik Lund]

AF focus or green dot is not usable with tilt and shift lenses for obvious reasons,,,

[JohnBrew]

The D700 was not known to have any of the problems of the D800 with focus, mirror alignment, etc. My first test of the SK was conducted on my deck with the trees about 15' away. Later I did some stitched landscapes which were fine. I repeat: I never had any problems with ANY other lens and that camera body!! I must say I was disappointed with the performance of the SK. Being advertised as a MF lens for 35mm I was expecting better image quality. I will say it is a difficult lens to master as it is completely different than a Nikon PCE. I certainly didn't master it, but I did get it to work. I have since found the first image made with the lens. The focus was on the oak tree in the foreground.

[Vilhelm]

Interesting experiences, but really hard to tell where the problem lies, mirror box or technique when shooting. Of course your copy could have been defective.

The lens resolves more detail than most lenses can, in fact Lenscore rates it as the 18th most resolving lens for DSLR, and the only non-supertele lenses ahead of it are the 135 APO-Sonnar and both Otuses plus Leica's APO-Summicron and Summilux Aspherical. The 20 most resolving lenses tested isn't exactly a dud league... http://www.lenscore.org/

[KarlMera]

Comparable to the Apo-Digitar and Apo-Componon HM 4,5/90mm the 90mm T/S is one of the best Schneider lenses for dslr cameras.

[Erik Lund]

John, You really can't dismiss such a sharp lens and MF lens due to focus problems using the dot for confirmation! Also; The AF sensor is just in proximity to where the AF brackets are shown...

[MILLIREHM]

Interesting list Vilhelm, thanks