Tue 26-Feb-13 06:23 AM | edited Tue 26-Feb-13 11:53 AM by lukaswerth
I have been using this lens now since last summer, and I find myself consistently confronted with a problem: at many settings,also with no tilt, it becomes quite unsharp on the left and the right side. For what I can see, the both sides go out of focus, because the area of sharpness seems to be distinctly bowl-shaped. This is annoying, as this becomes even more of a problem when the lens is shifted, particularly when I shift upwards to get the housetops.
A case in point is the picture below which I just uploaded: the enlargement possible is not quite enough, but if you go to the address pasted in and watch the enlarged version carefully you will see that the image is out of focus at the right side, while the wall and the man on the left side, being nearer to the camera, are in focus.
Has anyone else noted this, and is there a way around it? Can this be mended by Nikon?
By the way, it seems to me that the 45mm PC-E, which I don't possess, has the same kind of problem: on the Nikon website which shows sample images for d800/d800e, there is a downloadable file of a sunlit patch of forest moss taken with that lens, apparently tilted, and when you scroll through the file at 100%, you also see a distinct unsharpness at the edges.
Hm, I have not noticed that with mine. It is very sharp across the frame. Only at full shift, one edge gets slightly softer, the one which is near the border of the image circle.
I'd recommend to loosen all the knobs, align the front part as good as you can and then tighten them well. This is to make sure there is no "accidental" tilt: There is some play, so if you tighten knobs while front part is not perfectly centered, there can be an issue. Do this first with everything at 0, just to rule out lens issues.
thanks for your advice. Good to know that this is not with all lenses, so there is hope. That a shift lens gets softer at the edge of the image circle is of course to be expected.
With regard to tightening all the knobs, I suppose you mean the adjustment knobs? Well, I think I do that normally; I may have forgotten it once or twice in the heat of the action, but this is a persistent feature of my lens.
Yes I meant the adjustment knobs and the lock knobs at the opposite site. When I loosen them, there is a bit of play in my lens, and if I tighten them with the front part of the lens somewhat de-centered, it has an impact on edge sharpness. I.e. when the camera and lens are on the tripod, sometimes gravity is enough to misalign the lens front when the knobs are loose. So when tightening them, it's very important to check that there is no misalignment. So I just wanted to point this out, so you can rule it out.
I got one when I was using a D2X, I was pleased with the results. However when I got a D3X I found the edge softness unacceptable. I stopped using it. I would rather take a fixed lens, stack and crop. For many purposes the Zeiss 21 mm is my choice for this, however that too has poor corners when you are really fussy, so they need cropping off. For some architectural shots on a D800E I use a 15 mm Zeiss and keep it horizontal and use just the upper part of the frame. This seems better than fixing perspective in post processing which reduces detail too much.
The 85 mm PC Micro I have (not E) is a wonderfull lens. My best for document copying as it is so free of distortions and never soft. The 24 and 85 seem to be totally different. I have never used the 45 mm PCE so no comment.
I will have to ask Nikon and see what happens. I don't want to get rid of the lens, but if I can I will get it fixed. And I will try to get a used 28mm 3.5 shift lens and see how this will work for me.