Rick Posted July 26, 2013 Share #201 Posted July 26, 2013 Advertisement (gone after registration) It looks like condensation, if the atmosphere was humid did you make it worse by perhaps having your hand over the lens while walking around or taking the camera quickly from hot sun to cool shade? Steve No. Not humid at all, just 100 degrees. And, no there wasn't a smudge. The lens had been shooting fine all day up until this point. It was too hot to have humidity in or on the camera. The shot is what ever it is. I have several from that spot taken over 5 minutes that I got to do the same. 5 more minutes later we had walked to the bottom of the hill and the next shot of the town was fine. No more problems. CTF??? Kind of like WTF??? Link to post Share on other sites More sharing options...
Advertisement Posted July 26, 2013 Posted July 26, 2013 Hi Rick, Take a look here APO Summicron 50/2 ASPH: Central veiling flare / fogging. I'm sure you'll find what you were looking for!
adan Posted July 26, 2013 Share #202 Posted July 26, 2013 We have a term for this now "chicken-type-flare" Thanks Rick. We can always refer to it as CTF.. Ahh, what a way to be immortalized! OK, I will concede that this is not PURELY due to the rear element shape, although I think that would obviously play a role in the precise character of any lens's reflection pattern/tendency. As (apparently) do subject distance and aperture (per 01af). And the ASPH lenses' general ability to suppress other types of flare will make this type more obvious when it occurs. (My 90 TE "thin" may produce central reflection flaring - but who would know? It can flare for other reasons at the drop of a hat!) The 28 'cron has a concave surface on the next-to-rear element - but I won't push that any further. I went back and found the 28 'cron shots (2006, M8) where I noticed some central flare. However, they were back-lit shots, which raises the possibility of plain "old-fashioned" flare as the source. I don't think it was - but it makes it flawed data. Rick's example is more definitive. Link to post Share on other sites More sharing options...
lct Posted July 26, 2013 Share #203 Posted July 26, 2013 Referring back to Rick's post # 183Could it be that this kind of flare could have something to do with the large central section of the image that is overexposed? I was thinking that this would generate a bright central spot on the sensor that again could be reflected back to the lens etc... Just a matter of exposure IMO. Same view exposed on the lamp and on the clock. 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/208297-apo-summicron-502-asph-central-veiling-flare-fogging/?do=findComment&comment=2383031'>More sharing options...
jankap Posted July 26, 2013 Share #204 Posted July 26, 2013 This is my proposal. I made a picture for my TV-set (HD 1920 x 1080). Much black in the middle and white in the environment. With this we would have a standard situation. Everybody works with the same picture under comparable conditions. http://www.l-camera-forum.com/leica-forum/attachment.php?attachmentid=389478&stc=1&d=1374862865 The result with my Summicron 35 preAsph at f/16 is the following. http://www.l-camera-forum.com/leica-forum/attachment.php?attachmentid=389479&stc=1&d=1374862865 The contrast is lower, but does not show an extreme result. The TV-set is in my living room, without extreme lights outside the frame. So a lens hood was not necessary and not used. The picture was taken at 1 meter, filling the frame with the TV-set. Fstop 16, ISO 200, 1/6 sec. Is this a workable testsituation? Jan PS "fine art printer" is a german ambitious periodical about printing techniques. The original print is delivered online by the periodical. I reversed the inner part from white to black. 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/208297-apo-summicron-502-asph-central-veiling-flare-fogging/?do=findComment&comment=2383061'>More sharing options...
algrove Posted July 26, 2013 Share #205 Posted July 26, 2013 You guys have anything better to do than to put down a perfect lens? You know who you are. Link to post Share on other sites More sharing options...
Rick Posted July 26, 2013 Share #206 Posted July 26, 2013 Ok, I showed my Vernazza flare shot. I couldn't find my window shots so, I did a few again with my favorite window. I have changed my mind. I believe the Vernazza flare is just overexposed central image area that is causing common flare. It is just more noticeable because, the scene has dark areas around it. Decreasing exposure wouldn't eliminate it any more than decreasing exposure in a shot with sun in the frame would. I now believe that the Vernazza shot is just a bright area in the frame like sun, but less strong. The effect is the same - flare. Here is my window shot from today. I noticed something I hadn't before. Look closely and you will see a green image in the bottom half of the frame. It is a reflection of the window. I know you may not be able to tell because, you are not sitting here, but the reflection is of the two windows on the left. And, the reflected green image is upside down and reversed right to left. This fact is very important. You can also see common flare from a bright object in the frame (the windows) which is causing a veiling flare. This is just flare. Now, back to the green image. What is interesting to me is that in the same photograph we have an example of flare and what I believe to be sensor reflection. The color is right for sensor reflection and it is the same geometry as we used to commonly see posted here from the UV/IR filters on the M8 - Greenish color and upside-down and backwards. So, I belive now that the 50APO shots are all just simple flare of one sort or another. Sensor reflection is different. It is demonstrated by what we see in the bottom of this window picture. I still don't think the 50APO is exhibiting anything particularly flawed. I can reproduce this central type of desaturation flare all day long with any lens I shoot at that window below. What do the optical brainiacs here think. To me, clearly this window shot is an example of both flare and sensor reflection. Maybe, some of you can chime in and over-explain this. 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/208297-apo-summicron-502-asph-central-veiling-flare-fogging/?do=findComment&comment=2383083'>More sharing options...
Bill W Posted July 26, 2013 Share #207 Posted July 26, 2013 Advertisement (gone after registration) If nothing else I am gaining a lot of knowledge here. CTF just happens get over it! My 50 APO seems to work very well CTF or not. I am just gonna go out and shoot and not worry about it. Link to post Share on other sites More sharing options...
insomnia Posted July 26, 2013 Share #208 Posted July 26, 2013 If nothing else I am gaining a lot of knowledge here. CTF just happens get over it! My 50 APO seems to work very well CTF or not. I am just gonna go out and shoot and not worry about it. Great, so you are done here? We got it that you couldn't produce flare about 15 of your posts ago. A healthy discussion won't survive another 15 of trying to be funny. Link to post Share on other sites More sharing options...
Rick Posted July 26, 2013 Share #209 Posted July 26, 2013 Bill, if anything your 50APO has such high contrast that it makes it easier to see central desaturation flare or veiling flare or CTF or what ever we want to call these common flare effects. All of these posts on this thread are just flare. Name one and I'll explain it to anyone as just flare from a bright object in the image. By the way, you should see the the photos that algrove is emailing me with his 50 APO. I hope he posts some in the photo section. I wish I could say more. This guy can shoot wonderful photos. And, I really want this lens. Link to post Share on other sites More sharing options...
Jeff S Posted July 26, 2013 Share #210 Posted July 26, 2013 I think it comes down to which came first, the chicken or the flare. Jeff Link to post Share on other sites More sharing options...
Bill W Posted July 26, 2013 Share #211 Posted July 26, 2013 Great, so you are done here? We got it that you couldn't produce flare about 15 of your posts ago. A healthy discussion won't survive another 15 of trying to be funny. So sorry I irritated you insomnia, I will not contribute any thing additional unless its informative. It's just my personality. Link to post Share on other sites More sharing options...
Bill W Posted July 26, 2013 Share #212 Posted July 26, 2013 Bill, if anything your 50APO has such high contrast that it makes it easier to see central desaturation flare or veiling flare or CTF or what ever we want to call these common flare effects. All of these posts on this thread are just flare. Name one and I'll explain it to anyone as just flare from a bright object in the image. By the way, you should see the the photos that algrove is emailing me with his 50 APO. I hope he posts some in the photo section. I wish I could say more. This guy can shoot wonderful photos. And, I really want this lens. Thanks Rick if you do get one you will enjoy it. Link to post Share on other sites More sharing options...
Rick Posted July 26, 2013 Share #213 Posted July 26, 2013 So sorry I irritated you insomnia, I will not contribute any thing additional unless its informative. It's just my personality. Don't sweat it, you're fine. I'm not sure this will ever be a lens I'll own, but it is going to just continue to be a great lens as sensor technology continues to advance. Link to post Share on other sites More sharing options...
helged Posted July 26, 2013 Share #214 Posted July 26, 2013 If helged agrees, I will borrow one of his pictures and combine it with my diagram. . No problem (sorry for the late reply, i am on travel with limited access to the internet). Link to post Share on other sites More sharing options...
hoppyman Posted July 26, 2013 Share #215 Posted July 26, 2013 The Apo-Summicron-M 75 mm 1:2 Asph is very prone to this particular kind of central veiling flare (CVF) at medium and small apertures and short subject distance—at f/16 & f/11: CVF at less than 2 m/6 ft; at f/8: less than 1.5 m/5 ft; at f/5.6: less than 1.2 m/4 ft; at f/4: less than 0.9 m/3 ft; at f/2.8 & f/2: virtually no CVF at any distance. With the other lenses I don't find this CVF issue. So I guess Andy adan is wrong with his hypothesis about concave rear elements. Mods, maybe these other lenses references (including this of course) could be broken out into a different thread? I have shot only a tiny handful of frames with the new 50 (no flare of any kind visible) so I can't contribute anything more on that. I can force any lens I own to flare in some conditions. If I intend that I might shoot a test frame to confirm. Lluis Ripoll, Catalan photographer photo - Geoff Hopkinson photos at pbase.com Dr Ted Grant, Canadian Master photographer photo - Geoff Hopkinson photos at pbase.com but in practical use, I have never seen any instance of this distinct central area veiling flare (as illustrated in the first examples linked by the OP at #6). The discussion seems to be a bit muddied by flare in general as the thread has progressed. I like and use the APO Summicron M 75 ASPH a lot which is perhaps known from other threads. Can you link to results (maybe a new thread?) that illustrate how you arrived at this whole list of exact conditions? I typically use mine around f/4 in close, very seldom stopped right down but I have just never seen what you are reporting in any situation. Quite the opposite in that for female portraits I am invariably reducing clarity locally. There are a number of shots with this lens in my portrait gallery. I will point to these particular ones for examples at the closest distances. Spring dance photo - Geoff Hopkinson photos at pbase.com Natascha's Close Up photo - Geoff Hopkinson photos at pbase.com Isabelle (Izzy) Faith photo - Geoff Hopkinson photos at pbase.com Make Up Artist at work photo - Geoff Hopkinson photos at pbase.com Bec eyes photo - Geoff Hopkinson photos at pbase.com Bec's close up photo - Geoff Hopkinson photos at pbase.com Link to post Share on other sites More sharing options...
Rick Posted July 26, 2013 Share #216 Posted July 26, 2013 Geoff, the EVF appears to work quite well for me, as shown by my example (post 206) that took me exactly one shot to demonstrate the difference between a sensor reflection and lens flare. I used the EVF on the M to find the appropriate exposure, f-stop, distance, and light source. So, I guess I don't understand what you are talking about? We were talking about whether or not the pictures that displayed the central veiling was flare or sensor reflection. It is pretty clear to me that everything posted on this thread is simple lens flare. My last photo post (post 206) shows a sensor reflection which is not like any of the other examples of flare. The photo also demonstrates common flare. That's all. Use any method you want and try and post a photo of sensor reflection if, you think you have a better methodology for photographing an example. Or, you could just look at my post 206. Rick Link to post Share on other sites More sharing options...
semi-ambivalent Posted July 27, 2013 Share #217 Posted July 27, 2013 Just lurking here and, not having a 50 APO, I don't have a dog in this fight. But if people here can reliably reproduce this 'chicken flare', and with some people (e.g. RickLeica) postulating that it might be a reflection off the sensor, somebody should reproduce the circumstances and include some shots using the lens on a Leica that uses not a sensor but film. Perhaps surface differences between the two might help clarify the cause, especially if it is a sensor reflection and not an internal reflection shaped by the curves of the lens faces through which it passes. Good luck, it's interesting to see folks forcing this in to as scientific a test as they can manage. s-a Link to post Share on other sites More sharing options...
hoppyman Posted July 27, 2013 Share #218 Posted July 27, 2013 Rick too many words by me in my posts I guess. I deleted some now. I was trying to add that the EVF and LCD cannot show all of the properties of the raw file anyway. I follow that you said you can easily pick set ups with some flare of some kind using the previews. I don't know about sensor reflections or central veiling flare or concave element physics. I just know that I have never noted the distinct central area degradation as shown by that OP in some linked images at #6 with any lens or digital M myself. I think that the discussion has become confused on types of flare(any non image forming light) and their causes. Link to post Share on other sites More sharing options...
Rick Posted July 27, 2013 Share #219 Posted July 27, 2013 Just lurking here and... with some people (e.g. RickLeica) postulating that it might be a reflection off the sensor. Thanks for lurking. I changed my mind. I do not believe that the flare posted here by other members is sensor flare. Any flare that is from the sensor (reflection) will have to be geometrically upside-down and reversed and its ray has to pass through the center of the photograph. Anything else is just flare. Can you see the sensor reflection on my post 206 on the bottom half of the picture? That is sensor reflection. It is very pronounced. Even a diffuse veiling flare that might be thought to be a reflection off the sensor has to obey geometry. The image created has to be symmetrically across the image center and backwards and upside down. That is the geometry of a reflection off the sensor. None of the examples posted by other members follow these rules of the geometry. So, they are just common flare. Maybe, someone can link to those old M8 threads about the reflections off of the UV/IR filters and the sensor. These are a similar thing except, they use the filter surface as the second reflection. Rick Link to post Share on other sites More sharing options...
Rick Posted July 27, 2013 Share #220 Posted July 27, 2013 These are a similar thing except, they use the filter surface as the second reflection. Rick I should have said, "These are a similar thing except, they use the lens surface as the second reflection. Link to post Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.