a5m Posted April 4, 2020 Share #21 Posted April 4, 2020 Advertisement (gone after registration) 10 hours ago, mbray said: When I partly disassembled this lens (front group) the marks were definitely in/on the inner elements. 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! Seen this before on a Thambar; DAG confirmed it was separation. He said he could fix it on that particular lens, not sure if he'd do it for this one. Link to post Share on other sites More sharing options...
Advertisement Posted April 4, 2020 Posted April 4, 2020 Hi a5m, Take a look here about the Summilux 35 mm pre-asph.. I'm sure you'll find what you were looking for!
lct Posted April 4, 2020 Share #22 Posted April 4, 2020 16 hours ago, AndreasG said: Looks for me like a partial delamination of two cemented lenses. +1 Link to post Share on other sites More sharing options...
farnz Posted April 4, 2020 Share #23 Posted April 4, 2020 21 hours ago, mbray said: When I partly disassembled this lens (front group) the marks were definitely in/on the inner elements. Strangely enough, I have very similar marks on my 1970 35/1.4 Summilux pre-asph except here are four of them in a similar shape to the Southern Cross star formation. The marks were there when I bought the lens 3 years ago and I had the opportunuty to test the lens for a week before buying so I could rigorously test it and found that the marks had no effect on the lens's pictures at all. When examined closely they resemble tiny 3D crowns whose prongs move as the eye is moved around the lens. The thought is that they might be marks from a tool used to lift the lens element while it was being manufactured and has left a mark in the coating. It seems unlikely owing to the care taken during manufacture but all of the learned people I've quizzed over it haven't come up with a better explanation. No mind though because they don't affect the pictures. They might affect the resale value but I have no intention of ever selling it so no problem and I bought the lens at a generous discount anyway. Pete. Link to post Share on other sites More sharing options...
Malabito Posted April 4, 2020 Share #24 Posted April 4, 2020 If you refer to the preasph v2? ITs a very interesting lens, full of character when wide open, and quite sharp when closed down to f2. Sadly it focuses from 1m on, which i did found uncomfortable. I sold mine and really miss it.. Some images below with the m10, ( I have many more with the m240 if interested): 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! 5 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/308012-about-the-summilux-35-mm-pre-asph/?do=findComment&comment=3947043'>More sharing options...
ckuwajima Posted April 4, 2020 Share #25 Posted April 4, 2020 (edited) Yes, it has character, for the best and worst! This photo, taken wide open, highlights the worst: not really sharp at the edges and, boy, thats some coma! 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! Leica M10 & Summilux-M 35mm Pre-Asph In other situations it is just superb: Leica MP & Summilux-M 35mm Pre-Asph, Kodak Ektar 100 Edited April 4, 2020 by ckuwajima text correction 2 Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! Leica M10 & Summilux-M 35mm Pre-Asph In other situations it is just superb: Leica MP & Summilux-M 35mm Pre-Asph, Kodak Ektar 100 ' data-webShareUrl='https://www.l-camera-forum.com/topic/308012-about-the-summilux-35-mm-pre-asph/?do=findComment&comment=3947056'>More sharing options...
farnz Posted April 4, 2020 Share #26 Posted April 4, 2020 24 minutes ago, ckuwajima said: ... and, boy, thats some coma! Is that coma rather than blown spectral highlights? I ask because they're in just about every lit window all over the frame but I'd normally expect to see coma towards the edges but not in the (centre) sweet-spot. Pete. Link to post Share on other sites More sharing options...
ckuwajima Posted April 4, 2020 Share #27 Posted April 4, 2020 Advertisement (gone after registration) 8 minutes ago, farnz said: Is that coma rather than blown spectral highlights? I ask because they're in just about every lit window all over the frame but I'd normally expect to see coma towards the edges but not in the (centre) sweet-spot. Pete. A bit of shake and blown highlights are certainly user (me) induced errors in this imperfect photo 🙂 1 Link to post Share on other sites More sharing options...
AndreasG Posted April 5, 2020 Share #28 Posted April 5, 2020 In this photo you see the typical coma of the Summilux 35 V3 at full aperture in the right upper corner, and less at the left sider and centre. Photo without post processing. 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! 1 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/308012-about-the-summilux-35-mm-pre-asph/?do=findComment&comment=3947185'>More sharing options...
pgk Posted April 5, 2020 Share #29 Posted April 5, 2020 14 hours ago, farnz said: Is that coma rather than blown spectral highlights? I ask because they're in just about every lit window all over the frame but I'd normally expect to see coma towards the edges but not in the (centre) sweet-spot. Pete. Somewhere I have a film shot which shows significant coma of a light at night not in the centre but not a vast distance away. Wide open coma can be significant, especially in night shots. Link to post Share on other sites More sharing options...
Ko.Fe. Posted April 5, 2020 Share #30 Posted April 5, 2020 On 4/3/2020 at 12:29 PM, mbray said: When I partly disassembled this lens (front group) the marks were definitely in/on the inner elements. 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! Do you have x20 loupe? I use it to find out where trouble spot it. I had old Leitz lenses with those spots. It was fungus I dealt with. And I never seen glue separation to looks like this. My other old and not so old Leitz lenses had it. Link to post Share on other sites More sharing options...
farnz Posted April 5, 2020 Share #31 Posted April 5, 2020 55 minutes ago, pgk said: Somewhere I have a film shot which shows significant coma of a light at night not in the centre but not a vast distance away. Wide open coma can be significant, especially in night shots. That would be interesting since coma ("comatic aberration") is a function of spherical aberration and doesn't occur at the optical axis and rarely occurs close to it my reading informs me. At the optical axis the rays are straight through and coma can't occur there - it's when the rays are affected by the curve of the lens element(s) away from the centre that ray displacement happens and the focal points start to occur behind the image plane producing the fanned tails that we recognise as coma. Pete. Link to post Share on other sites More sharing options...
pgk Posted April 5, 2020 Share #32 Posted April 5, 2020 Somewhere I have the scan of the old transparency. From memory the 'fanned tails' as you describe them, get progressively worse into the corners but are evident surprisingly quickly off axis - but the photo shows point light sources (lamps) against a very dark blue sky so is a worst case. Link to post Share on other sites More sharing options...
adan Posted April 5, 2020 Share #33 Posted April 5, 2020 (edited) Pete - if a lens has coma, it is present at every point of the picture except the exact center (an infinitely-small point). There is no "coma switch" that turns on and off only at a radius of 4 mm or 7.26 mm from the center. Coma does increase out from the center of the image, and there may be a place where it will become perceptible to any particular person, influenced also by the image magnification and the brightness of point-light sources relative to a dark background. But "imperceptible" is not the same as "non-existent." In the images below (M9, 35 lux preASPH, f/1.4) we can see perceptible coma tails or fans already forming (even in a moderate-contrast area) at about 1.8 and 3.3 mm from the image center. They are not as extreme or obvious as the "airplane wing" coma+astigmatism tails in the top right - but they are there. It is this omnipresent coma that spreads light around and produces this lens's "dreamy, foggy" effect at f/1.4 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! Edited April 5, 2020 by adan 1 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/308012-about-the-summilux-35-mm-pre-asph/?do=findComment&comment=3947724'>More sharing options...
farnz Posted April 5, 2020 Share #34 Posted April 5, 2020 1 hour ago, adan said: if a lens has coma, it is present at every point of the picture except the exact center (an infinitely-small point). Agree, Andy, hence why I said it doesn't occur at the optical axis. Perhaps I should have said that it is rare to see it occur near to the optical axis rather than "... rarely occurs close to it ..." although I suspect we're in danger of splitting hairs.🙂 That's a good example you've included so thanks for clarifying. Pete. Link to post Share on other sites More sharing options...
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