mmradman Posted November 9, 2017 Share #21 Posted November 9, 2017 Advertisement (gone after registration) I remember when I compared the Lux to the Cron, each wide open, the bokeh of the Cron was significantly smoother. My money went for the Cron v2, even though I could have afforded the Lux. But the bokeh at 1.4 was nervous and nasty. No thanks. Wish I still had those images to post.When I bought Summilux 28mm smoothies of OOF never crossed my mind, however I think it has more to do with background than inherent lens magic. As I have picture to show I will demonstrate. Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/278535-28mm-summilux-help/?do=findComment&comment=3392774'>More sharing options...
Advertisement Posted November 9, 2017 Posted November 9, 2017 Hi mmradman, Take a look here 28mm Summilux Help. I'm sure you'll find what you were looking for!
Csacwp Posted November 10, 2017 Author Share #22 Posted November 10, 2017 I also just noticed that the lens vignettes more on one side than the other. Is this normal? My lens does not produce bokeh like the above shots... Link to post Share on other sites More sharing options...
helged Posted November 10, 2017 Share #23 Posted November 10, 2017 I also just noticed that the lens vignettes more on one side than the other. Is this normal? My lens does not produce bokeh like the above shots... Vignetting should be fairly symmetrical. You need a relatively large, evenly lit wall or a cloudy sky (or similar) to properly check this. If the vignetting isn't symmetrical, or if the focus show systematic differences between, say the outer left and right sides of an image, some of the glass elements might be off. I had a WATE showing mis-alinment; it was fixed after two 'inspections' by Leica. Link to post Share on other sites More sharing options...
anickpick Posted November 10, 2017 Share #24 Posted November 10, 2017 The vignetting should be equally strong in towards the edges. Link to post Share on other sites More sharing options...
Csacwp Posted November 10, 2017 Author Share #25 Posted November 10, 2017 Here are a few more raw files showing the vignetting and wonky bokeh. https://we.tl/x87ukWSV0o Link to post Share on other sites More sharing options...
Csacwp Posted November 10, 2017 Author Share #26 Posted November 10, 2017 Leica has reviewed my raw files, and they think that my lens might be decentered. They also think that the vignetting issue might be caused by an unaligned sensor in my SL. I repeated the test using my 75 lux and got similar uneven vignetting, so it certainly is a possibility. There's too much that can go wrong with digital cameras... makes me want to go back to film. Link to post Share on other sites More sharing options...
helged Posted November 11, 2017 Share #27 Posted November 11, 2017 Advertisement (gone after registration) Thanks for the info! I think you have been very unlucky. Its my clear understanding that the SL is a very robust body. And its the first time I have heard about de-centered 21Lux. But both will be fixed, hopefully without too long wait... Link to post Share on other sites More sharing options...
enboe Posted November 11, 2017 Share #28 Posted November 11, 2017 "wonky bokeh" https://we.tl/x87ukWSV0o I think we have a winner for phrase of the day, or a name for a new band. Eric Link to post Share on other sites More sharing options...
fsprow Posted November 11, 2017 Share #29 Posted November 11, 2017 While the vignetting may suggest the lens being decentered, I will offer my view that obsessing about out of focus areas is counterproductive. I've always found the value of soft focus areas is to draw attention to the area of interest in sharp focus, not to draw the viewers concentration to the OOF areas or any characteristics of same. Maybe just me. 1 Link to post Share on other sites More sharing options...
rscheffler Posted November 13, 2017 Share #30 Posted November 13, 2017 (edited) I remember when I compared the Lux to the Cron, each wide open, the bokeh of the Cron was significantly smoother. My money went for the Cron v2, even though I could have afforded the Lux. But the bokeh at 1.4 was nervous and nasty. No thanks. Wish I still had those images to post. I shot the 28 Cron v1 for around 4 years and last year replaced it with the 28 Lux. The above comment is inline with my feelings regarding the background rendering qualities of each. I preferred the 28 Cron. The 28 Lux wide open definitely shows a fair amount of double-edging in out of focus backgrounds. That said, I didn't like the Cron's different color tint compared to most of my other Leica M lenses (it leaned towards magenta), which meant it always required individual fine tuning when delivering images made with a range of lenses. And given the quirks of Leica high-ISO prior to the M10 (not so great with the M9 and a halving of the buffer depth with it and the M240 at a specific ISO threshold), the desire to collect as much light as possible was the primary factor for switching to the 28 Lux. Had I waited for the M10, maybe I would have kept the 28 Cron... Here are a few recent photos in a Google Drive gallery from a visit to a friend's place... The situation is different than your images - indoor vs. outdoor and no tree branches or grasses. But look at the background and there are some areas where you can see similarities. In the first image, the brown square on the wall behind the boy shows double imaging of text, similar to the Fayette St sign in a couple of your images in the second download set. This also happens in the out of focus features of the woman at left in the second image. The third image shows this again with the square on the wall in a slightly different position. The odd specular highlight shapes seen in some of your images can be seen in the specular highlight over the shoulder of the elderly man in the third image. I don't have other 28 Lux images readily at hand and currently don't have the time to delve into the archive to find more examples. I'm not sure how much of a difference it makes that your images were on the SL and mine on the M240. My feeling is your examples are somewhat harsher background rendering. Uneven vignetting suggests Leica might be correct in suggesting that something isn't quite right, whether lens decentering or proper sensor-lens mount alignment. If you also see uneven vignetting with other lenses then it suggests a camera problem. You can test for decentering with something like a brick wall test. Unfortunately sending this all off to Leica means waiting 1-2 months and might not result in much change, if any... If you'd have posted this a month ago, and I saw it, we could have met up in Baltimore (assuming that's where you are because the Walgreen's on E Fayette St photos were shot there). I was there for a visit and you could have tried my 28 Lux. Edited November 13, 2017 by rscheffler Link to post Share on other sites More sharing options...
Jamison Posted November 15, 2017 Share #31 Posted November 15, 2017 (edited) t may be worth considering the optical reasons for vignetting at wide open apertures. Take the lens off the camera, stop it down to f/8, hold it up to light and turn it left and right. On a wide angle, the aperture opening should follow you around a little. It tries to aim the full width of the circle at you. This is the built in design to the forward elements in the lens. Keep that in mine and do it again with f/2, almost full open on the Summilux, you will see that even though the effect is similar, it is cut off by the width limit of the lens. It only has so much glass to allow this. So at wide apertures the circle area gets cut off so the glass cannot gather as much light from edge areas, hence less exposure and darker edge image. This is one part of a lens design to combat vignetting. Incoming light is bent by each glass element and light rays from the image cross in the aperture plane so that a small aperture still gets the entire image, but a larger aperture gets more light and takes the light and focuses onto the light sensor or film. Imagine an incoming light ray running top left to bottom right in this diagram below. It bends with each lens crossing in the center and come out running parallel to from the inner element in the bottom right. Google light ray trace through lens element --- to see a lot of image examples of this. In every lens design, there are some inner reflections of glass to air surfaces that can bounce light up to the previous element. Problems can arise from surface to air reflections that may reflect again downward. Aspherical surfaces at an element edge may create a cross reflection. In any case, something is going on that goes away with smaller apertures when vignetting is not as pronounced. The 28mm M Summilux design: Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Aspherical design choices are to help create better focus across the entire image field, especially to the edges. For decades, wide angle lens design uses a retro focus based design so the back element groups no longer protruded a similar distance as the front element groups. The retro focus, keeps the back elements high up in the lens and avoids extreme angles for image edges hitting the light sensor and causing false color because the limitations of the sensor. Back in the days of film, this was not so much an issue. This whole shift in M design started with the change of the classic Schneider design of the 21mm f3.4 Super Angulon - M to the new version retro focus design 21mm f2.8 Elmarit. The 28mm redesign followed. I believe the 21mm R lenses redesign came first. In those years, the 21mm R needed to clear the mirror, so it got the retro-focus upgrade and the 21mm M needed to allow the M5 and future M designs to continue to be able to use the meter. I don't have access to any lens tests to know exactly what is causing the edge issue. I personally have worked only with the range of Leica lenses available in the 80's and own a collection from that era, so I have no direct experience with this lens. It looks like an excellent design. Edited November 15, 2017 by Jamison 1 Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! Aspherical design choices are to help create better focus across the entire image field, especially to the edges. For decades, wide angle lens design uses a retro focus based design so the back element groups no longer protruded a similar distance as the front element groups. The retro focus, keeps the back elements high up in the lens and avoids extreme angles for image edges hitting the light sensor and causing false color because the limitations of the sensor. Back in the days of film, this was not so much an issue. This whole shift in M design started with the change of the classic Schneider design of the 21mm f3.4 Super Angulon - M to the new version retro focus design 21mm f2.8 Elmarit. The 28mm redesign followed. I believe the 21mm R lenses redesign came first. In those years, the 21mm R needed to clear the mirror, so it got the retro-focus upgrade and the 21mm M needed to allow the M5 and future M designs to continue to be able to use the meter. I don't have access to any lens tests to know exactly what is causing the edge issue. I personally have worked only with the range of Leica lenses available in the 80's and own a collection from that era, so I have no direct experience with this lens. It looks like an excellent design. ' data-webShareUrl='https://www.l-camera-forum.com/topic/278535-28mm-summilux-help/?do=findComment&comment=3396400'>More sharing options...
Csacwp Posted November 20, 2017 Author Share #32 Posted November 20, 2017 An update- I just refretted the lens back from NJ. All seems well now. The repair notes say that the focus and focus mount were repaired. I have yet to test it on my SL, but on my M240 it performs as it should (no more wonky bokeh). Link to post Share on other sites More sharing options...
rscheffler Posted November 20, 2017 Share #33 Posted November 20, 2017 Csacwp: when did you send in the lens? I'm curious how long it took them because my 28 Lux has developed a loose focusing ring and needs servicing... Link to post Share on other sites More sharing options...
Csacwp Posted November 20, 2017 Author Share #34 Posted November 20, 2017 Took 3 days once they received it, but I had an “in” and jumped the line. Link to post Share on other sites More sharing options...
rscheffler Posted November 20, 2017 Share #35 Posted November 20, 2017 OK, thanks. I was going to say that seemed to be very fast turnaround compared to their usual 1-2 months... Link to post Share on other sites More sharing options...
Csacwp Posted November 21, 2017 Author Share #36 Posted November 21, 2017 (edited) Well, I shouldn’t get too excited... it looks like Leica NJ lost my SL. Two days of searching and they still cannot find it. Edited November 21, 2017 by Csacwp Link to post Share on other sites More sharing options...
Csacwp Posted November 22, 2017 Author Share #37 Posted November 22, 2017 More bad news... the lens seems to fit loosely to the M body, and the metal ring that screws onto the filter thread is now attached too tightly and will not come off, even when I use a rubber gripper. Link to post Share on other sites More sharing options...
Csacwp Posted November 30, 2017 Author Share #38 Posted November 30, 2017 An update. Aside from the two issues mentioned above, there is also now a large speck in the middle of one of the lens elements. This is a new lens mind you, only used to take a few test pictures. I sent it back to NJ for a second time, and they told me that it now has to go to Germany for repair. I asked for a loaner, and they said that the best they could do would be to send a 50 Summicron. That’s not going to do it for me... I already own one, and I really needed the 28mm for a project. I’ve now asked for a replacement lens since mine is clearly a dud, and we’ll see what they say. Link to post Share on other sites More sharing options...
LeicaPassion Posted November 30, 2017 Share #39 Posted November 30, 2017 My 21mm has been at Leica NJ for more than a month. While I'm glad that you had a quick turnaround time, Leica should not play favorites. 1 Link to post Share on other sites More sharing options...
Csacwp Posted November 30, 2017 Author Share #40 Posted November 30, 2017 I had previously worked with one of the repair guys on a previous repair. All I had to do was ask nicely to have it rushed. You probably could have gotten away with the same thing. Link to post Share on other sites More sharing options...
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