Do you claim my lens has field curvature which is shape of the tree in front?
I don't claim anything Samuli. I don't have that lens and I don't see much from your examples. I am just saying that given the description from previous posts, although not conclusive, field curvature would be the first thing that I would think about.
or in this shot, where the background is way too much blurred for 25mm lens
I don't see the blur that you describe, so I may be wrong. But the background distance in the picture incrementally increases as you go up in the image. If my understanding of effect of field curvature on distance of exact focus is correct and if my brain still works well at this late hour, I would expect that the focus would follow the ground in the lower part, but would go in the opposite direction in the upper part, making the background blurred sooner than lens that does not have field curvature?
Mirek Elsner wrote:
I don't see the blur that you describe, so I may be wrong. But the background distance in the picture incrementally increases as you go up in the image. If my understanding of effect of field curvature on distance of exact focus is correct and if my brain still works well at this late hour, I would expect that the focus would follow the ground in the lower part, but would go in the opposite direction in the upper part, making the background blurred sooner than lens that does not have field curvature?
Mirek please see the crops on page post #15 & #18. The "too shallow DOF" is happening all over image and crop is naturally from one place only showing in focus and blurred background. From these webthumbnails where whole picture is shrunk to 975px narrow you cannot see it, that was not the point neither.
Enough talk more images. So this was about CZ28mm and wider best images as far as I remember...
...f/11 with 5Dmk1, 0.5s, ISO 100
...f/11 with 1DmkIII, HDR, ISO 100
...f/2.8 with 5DmkII, 1/30s, ISO 100
