17mm TS-E and focal plane curvature?

Well, I just tried a different lens (had to for my curiosity) and it has exactly the same properties. I actually did a bit more testing and don't believe this is focal plane curvature (nor does it make sense that this is needed for shift - it would be very bad) because a flat subject at f4 looks good and I cant appreciably sharpen the sides by changing focus.

I also discovered the DOF and infinity markings on this lens are actually useful. Another really easy way of getting the effect I am seeing (if anyone wants to try) is to set the aperture at f11 and the f11 DOF (far) mark at infinity and take a shot of an expansive landscape. You should notice that the center is indeed sharp, but the sides beyond a certain distance are certainly not (no tilt). Shift obviously should not change anything, the image just moves around.

I'm not saying this is a bad lens, or that one cannot get a sharp 'back-to-front' landscape image, it just has a certain characteristic which I'm a bit surprised isn't as well known or talked about. Or maybe both lenses I tested have the same problem from the same batch - they were both purchased from B&H. It seems a little unlikely though, especially as the images from them are near to identical as far as I can tell except a slight shift due to centering differences.

I'm probably going to do some more digging on this, but if anyone wants example shots (RAW or jpeg) send me a pm and I'll email good examples (better than the one I posted). Anyone wants to do a similar test and let us/me know? Just take a shot of a nice open landscape at f11 with the far f11 DOF mark at infinity and compare the center and sides of the image.

For a basis of comparison try 17mm on the Canon 17-40/4 or 16-35/2.8 with your same corner test. The 17-40 in particular is quite soft and distorted in the corners on FF. It bothered me a lot, but some don't mind much as the center is sharp enough.

Mike K wrote in post #13699459
For a basis of comparison try 17mm on the Canon 17-40/4 or 16-35/2.8 with your same corner test. The 17-40 in particular is quite soft and distorted in the corners on FF. It bothered me a lot, but some don't mind much as the center is sharp enough.

Of course, unfortunately my 17-40 appears to have problems which I only noticed when I started shooting it FF. On crop is seemed fine, on FF I started to notice strange problems. One side is soft and the other much sharper at 17mm (well it appears to have focal plane problems, but anyway..). It's currently back in for repairs. Overall though I like the TSE most for the shift, with the sharpness a close second. If there were a sharper, cheaper Zeiss of this FL, I'd still choose the TSE.

But, I will say that doing the above HFD test and comparing to the 17-40, the 17-40 is sharper on its 'good' side. Note - I'm talking about 'sides' or the frame, particularly near infinity, rather than corners. The 'near' corners are very sharp on the TSE if they are within the HFD, where as of course the 17-40 is not. But I need to get it properly fixed for a really fair comparison.

But of course, moving the focus on the TSE towards infinity and perhaps stopping down a bit (if I need the foreground) yields results that are far superior to the 17-40. When in focus my TSE is like Wim's example - you just keep zooming in and getting more detail until you see the pixels.

I've already taken by far the sharpest landscape shots I have ever seen at full resolution, either by not being up super-close to the foreground or tilting or with just focus stacking 2-3 images (one combined with tilt that worked really well). The lens is amazing and seemingly sharper than the dpreview scores would indicate (especially at f11) when qualitatively compared with my other lenses. It's certainly as sharp, or sharper than I 'need'.

In looking around, I have seen a couple of comments about being careful with focusing and making sure the sides of the image are in focus, but nothing very specific.

Turning wrote in post #13668028
I recently bought a ts-e24mm ii and at the risk of getting boxed around the ears a bit again (like the tse-24mm ii thread):

When I shoot the lens close and square to a flat surface (wall), close enough to have a newspaper mostly fill the viewfinder (maybe 3ft?),with the center sharp the edges are visibly softer than say my 24-105L both at f/4 (swapped in changing nothing but focus).

Even at f/6.3 a close flat surface is not all in focus. Esp the left side.

Multiple tries yield the same results.

When I focus further it does not seem to be nearly as true if at all (not positive on that as harder to control)....

Anyone with a tse17 or tse 24II willing to shoot a flat target up close at f /3.5 or f/4 and report? I am curious....

I am talking no shift no tilt here.

btw as I posted elsewhere I tried another ts-e 24mm ii which doesn't have the same problems as the first one. Compared back to back and this one behaves like I was expecting.

I am glad I tried another one before giving up.

Turning wrote in post #13701336
btw as I posted elsewhere I tried another ts-e 24mm ii which doesn't have the same problems as the first one. Compared back to back and this one behaves like I was expecting.

I am glad I tried another one before giving up.

Yea, even with these expensive lenses, it seems thinks can go wrong in manufacturing. I used to be less inclined to properly test a new lens, but now I do for sure.

The flat-wall test at f4 looked good with my 17mm with no obvious focal plane curvature, even when shifted and no tests show any obvious differences from one side to another.

Still hoping someone will replicate taking a shot with the f11 DOF mark at infinity on an open landscape though.