LarsHP
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From what I have gathered, the new Thypoch Simera 28mm f/1.4 performs well regarding purple fringing and has low vignetting wide open, but it has a less than wonderful flare resistance, and ergonomically it's a bit odd, having the focus ring near the mount.
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Wide open, there is sometimes annoying purple fringing, yes. I think that, if you want an f/1.4 /or f/1.5 lens, then I accept that the wide open color correction won't be as good as an f/2, or even an f/2.8, lens. For these instances, stopping down to f/2.8 removes most of the LoCA, and in addition, there will be much less vignetting than an f/2.8 lens has wide open.
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What are you referring to that makes you doubt? Rendering / bokeh?
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Haha! When I test the lens wide open at purely infinity distance, there is nothing odd to see. If you look closer, you will see that objects (slightly) out of focus is closer than what is in focus, according to the plane of focus. I chose this scene for the very reason that there are objects in various places of the frame in various distances, because that is very revealing regarding how the plane of focus goes. Naturally, towards the sides, there is both more depth of field caused by optical vignetting as well as field curvature, but there is also gradually slightly lower resolution away from the center, since this shot is wide open.
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Right. Here you go: https://drive.google.com/file/d/1ZjUm1-xlnD_84AnZWFQsXX0Hu180E6iz/view?usp=drive_link EDIT: Now the link is public.
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I just discovered that the image is downsampled to 2480 pixels by the forum software, so not as easy to spot what I see in the original 24MP file.
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The lens has INWARD bending field curvature. This quick infinity shot clearly demonstrates that there is zero outward bending field curvature: On the contrary, it bends inward. Focus is placed in the center on the other side of the fjord. Observations: 1) In the center, the wire is blurred and has purple fringing, but gets progressively more in focus towards the sides, which means inward bending field curvature. 2) Checking the sharpness of the road: In the center, it is blurred, while in each side, it is pulled into focus. 3) Even the weed near the edge of the image that sticks up through the snow on this side of the road is in focus, while in the center (on this side of the road), it's clearly blurred. 4) The yellow tractor is slightly blurred, while the other tractor at the very edge of the frame on the right is in focus. All these observations make me conclude that the lens has inward bending field curvature. In fact, no matter what focus distance, I see no outward bending field curvature. I do however see optical vignetting, as expected, which sometimes makes background blur towards the sides and corners slightly lower. In fact, I have concluded that, if a lens has a typical or marked amount of optical vignetting, while having a perfectly flat plane of focus, the increased depth of field in the sides and corners will make it look like it has outward field curvature if the background is only slightly out of focus in the center. - Note: This image is 4000 pixels wide in order to clearly demonstrate my point.
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Optical vignetting explains that easily. There are also a lot more trees there, which may explain why you see it that way. Check how sharpness on the road looks. Focus appears to bend inwards near each edge of the frame. When I focus at infinity in the center, which is slightly shorter than the hard stop, and compare it to the sides or corners, I need to move focus to the hard stop in order to get best focus. That means the lens has inward bending field curvature.
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I just re-checked my lens. If anything, I see inward bending field curvature near the edges of the frame at 2 to 3 meter focus distance. See the below image. Unless the Kolari Ultra-Thin Z6 has markedly thinner sensor glass, which I doubt, I expect the difference must be caused by sample variation. My (now long sold) 28mm Summicron-M Asph II had a different plane of focus when I bought it than after I had it sent to Wetzlar, so this seems to indicate that tiny assembly variances may cause a difference in field curvature.
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Sample shot at minimum focus distance, wide open. Respectively, full image and 100% crop, using 24MP camera. Moderate sharpening in ACR. Sharpness in the central area is still good at 0.5-meter distance, but away from the center it gets progressively worse.
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You are most welcome! I do get the understanding that the Simera has some strengths over the Nokton, specifically optical vignetting and smoother bokeh in general. Field curvature may also be inward bending at medium distance, like the 2-meter test you shared at Fred Miranda's site (which I liked to in a previous post in this thread). Can you share whether the Simera has inward bending field curvature at medium focus distance already now? 😇
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Today, Bastian Kratzke published his review of the 28mm Nokton here: https://phillipreeve.net/blog/review-voigtlander-vm-28mm-1-5-nokton There is not much for him to complain about. 😊
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The above images with the 7A 28/1.4 looks bad in my opinion. I had the FE+ version of that lens (for use with stock mirrorless cameras), and it was usable wide open at close distances, but at medium to long distances it was awful outside the center. Stopped down to f/4 or f/5.6 it was really sharp, though. For close portraits wide open it was fine, but certainly not for full body. Bokeh was mostly smooth, though.
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Thanks. I would point you to the thread at Fred Miranda's site where he has comparisons to the Summilux, Ultron II, as well as lots of sample images, including by members. Fred's infinity test on the M10-R show that it's a very high resolving lens. However, since you don't mind a slower lens with more vignetting at (f/2 or) f/2.8, and apparently rather prefer resolution and flat plane of focus, I would suggest the Ultron II. It's about the size of an Elmarit-M Asph if I am not mistaken. It has an 39mm filter thread. I know it's noticeably smaller than the Summicron-M Asph II, as well as sharper than the Leica counterpart. I sold the 'cron after getting the Voigtländer. If you search for the 28mm Ultron II here, you will find a thread with my sample images, including a link to side-by-side test shots with the Summicron.
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You are welcome. I use a Kolari Vision Ultra-Thin sensor glass modified Nikon Z6. It probably performs like a 24MP Leica M11 (since both have BSI sensor). My side-by-side test with M 240 as well as Fred Miranda's test with his M cameras versus a Sony camera with Kolari UT mod show that regarding sharpness and field curvature, they perform indistinguishably.
