Robert_M Posted September 2, 2012 Share #61 Posted September 2, 2012 Advertisement (gone after registration) K-H, Well, it appears that the aperture stop is indeed far enough back in the optical system to help block out the ghost when stopped down. Glad that little test worked. It does appear that f/8 to f/11 is the way to go. When the bright light is nearer the center, you will need to stop down more than when the light is at the edge of the field. The actual intensity of the light shouldn't matter. It is the ratio of the original image to the ghost which is constant. By stopping down, you are able to increase that ratio. It should all work the same for your original, night, skyline image. However, the couple bright lights right at the center may continue to give you a problem. I'd suggest framing the image so the skyline does not go across the center of the frame. Might be a good time to follow the "rule of thirds" . Will be interesting to see how the skyline comes out now. I hope nobody takes all the discussion in this thread as any criticism of that APO 280/4 lens. I view it as an exercise in understanding the lens parameters and limits in detail. I guess my background leads me to obsessively understand any and all instrumentation I use. I don't have that lens myself. But I understand it is a superb lens. I'm jealous of you! I wish I had that lens even though I don't even have a camera I could use it on. That sounds crazy... Good luck. RM Link to post Share on other sites More sharing options...
Advertisement Posted September 2, 2012 Posted September 2, 2012 Hi Robert_M, Take a look here LEICA SERIE 5.5 NDx1 13026 GERMANY. I'm sure you'll find what you were looking for!
k-hawinkler Posted September 4, 2012 Author Share #62 Posted September 4, 2012 K-H, Well, it appears that the aperture stop is indeed far enough back in the optical system to help block out the ghost when stopped down. Glad that little test worked. It does appear that f/8 to f/11 is the way to go. When the bright light is nearer the center, you will need to stop down more than when the light is at the edge of the field. The actual intensity of the light shouldn't matter. It is the ratio of the original image to the ghost which is constant. By stopping down, you are able to increase that ratio. It should all work the same for your original, night, skyline image. However, the couple bright lights right at the center may continue to give you a problem. I'd suggest framing the image so the skyline does not go across the center of the frame. Might be a good time to follow the "rule of thirds" . Will be interesting to see how the skyline comes out now. I hope nobody takes all the discussion in this thread as any criticism of that APO 280/4 lens. I view it as an exercise in understanding the lens parameters and limits in detail. I guess my background leads me to obsessively understand any and all instrumentation I use. I don't have that lens myself. But I understand it is a superb lens. I'm jealous of you! I wish I had that lens even though I don't even have a camera I could use it on. That sounds crazy... Good luck. RM Hi RM, Many thanks again for your support. Not crazy at all - as far as I am concerned. The Leica APO-TELYT-R 1:4/280 can deliver stunning performance, but sometimes leaves a characteristic signature behind in images taken with it, so to say its fingerprints. I am slowly seeming to get the hang of using it. So, before continuing our analysis attempt of some of its inner workings, first some pictures taken with that lens on the Sony NEX-7. Here goes: The first is an OOC JPG image of the Moon. 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! This is the Moon's reflection of the Buckman Rapids of the Rio Grande. I like the wavy pattern of this 15 s exposure. This is an OOC JPG image as I saw it in the EVF of the NEX-7. This is a CS6 developed version from Sony's raw format of the previous image. Of course, noise is amplified significantly and I didn't try to hide that. I am just amazed about the colors that came out. As this was shot wide open, please notice the little glare in the trees at the lower left. The lens' characteristic signature again. Several months ago I noticed in the pitch darkness some lights in an area where there normally aren't any lights. So I had a look with my lens/camera combination. What did I see? A little party next to the Rio Grande with a small fire in the head lights of a car. Well, typically we don't have forest fires that early in the season and these folks didn't start one either. High resolution versions of these images can be found here: 2012-09-04 2•NEX-7+Telyt 280/4 - winklers' Photos Enjoy! Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! This is the Moon's reflection of the Buckman Rapids of the Rio Grande. I like the wavy pattern of this 15 s exposure. This is an OOC JPG image as I saw it in the EVF of the NEX-7. This is a CS6 developed version from Sony's raw format of the previous image. Of course, noise is amplified significantly and I didn't try to hide that. I am just amazed about the colors that came out. As this was shot wide open, please notice the little glare in the trees at the lower left. The lens' characteristic signature again. Several months ago I noticed in the pitch darkness some lights in an area where there normally aren't any lights. So I had a look with my lens/camera combination. What did I see? A little party next to the Rio Grande with a small fire in the head lights of a car. Well, typically we don't have forest fires that early in the season and these folks didn't start one either. High resolution versions of these images can be found here: 2012-09-04 2•NEX-7+Telyt 280/4 - winklers' Photos Enjoy! ' data-webShareUrl='https://www.l-camera-forum.com/topic/186459-leica-serie-55-ndx1-13026-germany/?do=findComment&comment=2104553'>More sharing options...
k-hawinkler Posted September 4, 2012 Author Share #63 Posted September 4, 2012 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! Well that's easy to figure out from the earlier moon shots. First determine the middle point of the entire image, blue lines. The yellow lines show the four quadrants. Start at the pesky flare, trace back through the middle, and continue going out an equal distance as from the flare to the middle. That's about it. Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! Well that's easy to figure out from the earlier moon shots. First determine the middle point of the entire image, blue lines. The yellow lines show the four quadrants. Start at the pesky flare, trace back through the middle, and continue going out an equal distance as from the flare to the middle. That's about it. ' data-webShareUrl='https://www.l-camera-forum.com/topic/186459-leica-serie-55-ndx1-13026-germany/?do=findComment&comment=2104566'>More sharing options...
k-hawinkler Posted September 4, 2012 Author Share #64 Posted September 4, 2012 K-H, Well, it appears that the aperture stop is indeed far enough back in the optical system to help block out the ghost when stopped down. Glad that little test worked. It does appear that f/8 to f/11 is the way to go. When the bright light is nearer the center, you will need to stop down more than when the light is at the edge of the field. The actual intensity of the light shouldn't matter. It is the ratio of the original image to the ghost which is constant. By stopping down, you are able to increase that ratio. It should all work the same for your original, night, skyline image. However, the couple bright lights right at the center may continue to give you a problem. I'd suggest framing the image so the skyline does not go across the center of the frame. Might be a good time to follow the "rule of thirds" . Will be interesting to see how the skyline comes out now. I hope nobody takes all the discussion in this thread as any criticism of that APO 280/4 lens. I view it as an exercise in understanding the lens parameters and limits in detail. I guess my background leads me to obsessively understand any and all instrumentation I use. I don't have that lens myself. But I understand it is a superb lens. I'm jealous of you! I wish I had that lens even though I don't even have a camera I could use it on. That sounds crazy... Good luck. RM Hi RM, I agree, lights at the center may be problematic. "rule of thirds" is a good idea but sometimes difficult to follow. Here is one such example: The greenish/blueish flares are reflections from the car lights. 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! As the car moves, so do the flares. BTW, between taking these two shots from about a mile's distance I also recorded a short video clip, posted here 2012-09-04 2•NEX-7+Telyt 280/4 - winklers' Photos One can see a person leaving the building, getting into the car, and departing. High resolution versions of the two images can be found there as well. Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! As the car moves, so do the flares. BTW, between taking these two shots from about a mile's distance I also recorded a short video clip, posted here 2012-09-04 2•NEX-7+Telyt 280/4 - winklers' Photos One can see a person leaving the building, getting into the car, and departing. High resolution versions of the two images can be found there as well. ' data-webShareUrl='https://www.l-camera-forum.com/topic/186459-leica-serie-55-ndx1-13026-germany/?do=findComment&comment=2104586'>More sharing options...
k-hawinkler Posted September 4, 2012 Author Share #65 Posted September 4, 2012 K-H, Well, it appears that the aperture stop is indeed far enough back in the optical system to help block out the ghost when stopped down. Glad that little test worked. It does appear that f/8 to f/11 is the way to go. When the bright light is nearer the center, you will need to stop down more than when the light is at the edge of the field. The actual intensity of the light shouldn't matter. It is the ratio of the original image to the ghost which is constant. By stopping down, you are able to increase that ratio. It should all work the same for your original, night, skyline image. However, the couple bright lights right at the center may continue to give you a problem. I'd suggest framing the image so the skyline does not go across the center of the frame. Might be a good time to follow the "rule of thirds" . Will be interesting to see how the skyline comes out now. I hope nobody takes all the discussion in this thread as any criticism of that APO 280/4 lens. I view it as an exercise in understanding the lens parameters and limits in detail. I guess my background leads me to obsessively understand any and all instrumentation I use. I don't have that lens myself. But I understand it is a superb lens. I'm jealous of you! I wish I had that lens even though I don't even have a camera I could use it on. That sounds crazy... Good luck. RM Hi RM, Thanks. Now an example you probably have been waiting for. The first pair of images was shot at f=4 and ISO=100 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! The second pair at f=11 and ISO=800, exposure time constant at 15 s. The first image in each pair is an OOC JPG. The second images were derived from raw files. As you can see, for the f=4 case there is a tiny green flare, right below the red antenna lights to the left, reflecting of a strong light source to the lower right, but not that far below the center line. For the f=11 case that flare is absent - as expected. My take: The Leica APO-TELYT-R 1:4/280 was meant to be shot wide open. That is one of its main attractions! At heart I am sort of a root cause analysis type of guy. I would like to attack a problem by its root and not muck around with its symptoms. Of course, that's not always feasible. So, in this case we seem to have two contributing factors, namely reflections off the camera sensor and off the front flat plate of the lens. Camera sensors are what they are and their makers probably don't care how the 1:4/280 APO lens reacts to them. Furthermore, I happen to like the APS-C size NEX-7 sensor. A 36 MP D800/E for example would need about 57 MP to achieve the same resolution as the 24 MP NEX-7, taking into account their specific sensor dimensions. So that leaves for consideration reducing the reflections of the lens' front plate. I would naively think that modern coatings should be able to achieve that, hopefully at an economical price point. What do you think? I wonder if Leica could be convinced of that course of action? Thanks again for your help. Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! The second pair at f=11 and ISO=800, exposure time constant at 15 s. The first image in each pair is an OOC JPG. The second images were derived from raw files. As you can see, for the f=4 case there is a tiny green flare, right below the red antenna lights to the left, reflecting of a strong light source to the lower right, but not that far below the center line. For the f=11 case that flare is absent - as expected. My take: The Leica APO-TELYT-R 1:4/280 was meant to be shot wide open. That is one of its main attractions! At heart I am sort of a root cause analysis type of guy. I would like to attack a problem by its root and not muck around with its symptoms. Of course, that's not always feasible. So, in this case we seem to have two contributing factors, namely reflections off the camera sensor and off the front flat plate of the lens. Camera sensors are what they are and their makers probably don't care how the 1:4/280 APO lens reacts to them. Furthermore, I happen to like the APS-C size NEX-7 sensor. A 36 MP D800/E for example would need about 57 MP to achieve the same resolution as the 24 MP NEX-7, taking into account their specific sensor dimensions. So that leaves for consideration reducing the reflections of the lens' front plate. I would naively think that modern coatings should be able to achieve that, hopefully at an economical price point. What do you think? I wonder if Leica could be convinced of that course of action? Thanks again for your help. ' data-webShareUrl='https://www.l-camera-forum.com/topic/186459-leica-serie-55-ndx1-13026-germany/?do=findComment&comment=2104632'>More sharing options...
jaapv Posted September 4, 2012 Share #66 Posted September 4, 2012 What course of action? the lens has been out of production for many years, and to remove the front element and recoat it, even if that were possible or effective, would cost - well, I don't want to spoil my day by thinking about the price, but I do know that replacing the front element in the early nineties was about 1000 Deutschmark, when the whole lens cost less than 7000. I don't think it would be straightforward technically, either. With lenses of this level the coatings are part of the optical calculation. Link to post Share on other sites More sharing options...
Michael Geschlecht Posted September 4, 2012 Share #67 Posted September 4, 2012 Advertisement (gone after registration) Hello Everybody, It seems easier to begin solving this problem by coating the surface of 1 sensor than to coat the surface/s of many lenses. Even tho it may not be readilly apparent, this form of image reflection is probably effecting, @ the very least, the micro-contrast of every lens. I'm not saying micro-contrast, etc are not already very good. I am saying this might be a way to make every lens perform just a little better. Best Regards, Michael btw: Can't you determine the lens surface/s involved w/ the secondary image since you know: The millimetric distance between the centers of the images @ infinity. The physical/optical distance the of the diaphram from the sensor. The difference in the size of the flare "overflow" image as the diaphram is closed down. Link to post Share on other sites More sharing options...
k-hawinkler Posted September 4, 2012 Author Share #68 Posted September 4, 2012 Hi Michael, Thanks for the feedback. Of course, they should build the sensors as good as possible. However, let me point out that not every lens has this problem. For example, the Telyt-V 1:4.8/280 version 3 is fine as long as one doesn't put a filter on. Link to post Share on other sites More sharing options...
jankap Posted September 4, 2012 Share #69 Posted September 4, 2012 Does the degree of the coating go into the calculation of the optics? Interesting thread! Jan Link to post Share on other sites More sharing options...
jaapv Posted September 4, 2012 Share #70 Posted September 4, 2012 On the 280/4.0 even the rear filter is part of the calculation. The lens is visibly degraded without the filter at the back. Link to post Share on other sites More sharing options...
Robert_M Posted September 5, 2012 Share #71 Posted September 5, 2012 I don't know what programs and software Leica uses to design lenses (it may be their own proprietary software). There are two very expensive programs out there these days which are standards in the optical industry; ZEMAX and Code V. I can tell you that these are what is used in the front line unique research instrument design (Mars images, Earth imagining, etc.). I'm somewhat familiar with ZEMAX and not the others. That program does include the facility to put lens coatings into the optical sequence. Regarding the flat elements: The flat input element would have NO effect on an object at infinity (the input light is normal to both surfaces) and will start to have some influence with closer focus objects. However, the rear (S5.5 filter) element WILL always have converging rays coming through. That element will indeed have an influence on the optical prescription. Note, that the influence on that rear filter is not nearly so strong with the telescope style Telyt lenses since the focus is so long and the light is not converging so much through those filters. So with the 400/6.8 and 560/6.8 that filter doesn't matter as much as with a true telephoto like the APO 280/4. I'd guess that one could remove that front flat element without any influence on the optics, other than protection of the next, soft element. Then a standard filter could be used for protection when necessary. And, it could be removed for night shots. I can understand that this is not the way to design consumer products. But it is the way to design a lens for high dynamic range (night lights) shots. I also wonder; is that next element really soft or is it the coating that is soft and subject to danger? RM Link to post Share on other sites More sharing options...
Robert_M Posted September 5, 2012 Share #72 Posted September 5, 2012 K-H, Nice set of tests. Thanks for the images. Yes, the real hearth of the problem is the reflection off the camera sensor surface. I'd suspect that this has more to do with the Bayer filter layer than any protective cover filter. Would be interesting to see if there is a difference with other camera sensors. With time, there will be other choices to try. RM Link to post Share on other sites More sharing options...
Rick Posted September 5, 2012 Share #73 Posted September 5, 2012 Karl, I am away on holiday so I can't test to see if I can reproduce your results now (left that lens at home) but, when I get home I'll try . But, I do have the 280 Telyt APO 2.8 with me. It is a clear night so I'm going to go find the moon and try it with that lens. What is of interest is that the 2.8 has a removable front element (ND filter). so I can see if I get that ghost effect with the lens and then remove the ND filter protector. The ND filter is to protect the front element. In the booklet that comes with the lens it states so much and it gives very explicit directions how to clean the front element right down to the solution to mix and the motion to clean and the type of cloth. I'm off to find the moon... Link to post Share on other sites More sharing options...
k-hawinkler Posted September 5, 2012 Author Share #74 Posted September 5, 2012 Rick, Thanks. Good luck. Which camera are you using? Link to post Share on other sites More sharing options...
Rick Posted September 5, 2012 Share #75 Posted September 5, 2012 No moonrise for another 1-1/2 hours here. The Photographer's Ephemeris is a great app for showing where and when the sun and moon will be so you can plan your pictures. It says no moon for a while here. Link to post Share on other sites More sharing options...
Rick Posted September 5, 2012 Share #76 Posted September 5, 2012 Rick, Thanks. Good luck. Which camera are you using? Sold the 5DII but, have a 5D that I steel off of our retinal camera from time to time (goat pictures in Nature sub-forum). By the way, I really enjoy your photo's on your site, nice. I think it has to be the front ND filter and sensor. The geometry just looks right. Maybe I can prove it, at least on the 2.8. Also, the ND on the 2.8 flares if shot with the sun on it much more than without it. I take it off sometimes. Link to post Share on other sites More sharing options...
k-hawinkler Posted September 5, 2012 Author Share #77 Posted September 5, 2012 Sold the 5DII but, have a 5D that I steel off of our retinal camera from time to time (goat pictures in Nature sub-forum). By the way, I really enjoy your photo's on your site, nice. I think it has to be the front ND filter and sensor. The geometry just looks right. Maybe I can prove it, at least on the 2.8. Also, the ND on the 2.8 flares if shot with the sun on it much more than without it. I take it off sometimes. Hi Rick, Thanks for the feedback. Much appreciated. Yup, that makes the most sense. Link to post Share on other sites More sharing options...
k-hawinkler Posted September 5, 2012 Author Share #78 Posted September 5, 2012 I would like to come back to the first image in this thread in post #3 that made me have a closer look http://www.l-camera-forum.com/leica-forum/2160547-post3.html This is my attempt to indicate for some of the flares which intense lights caused the reflections. 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! Obviously one can perform this analysis only on a complete image, i.e. the shape hasn't changed or parts cut off. Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! Obviously one can perform this analysis only on a complete image, i.e. the shape hasn't changed or parts cut off. ' data-webShareUrl='https://www.l-camera-forum.com/topic/186459-leica-serie-55-ndx1-13026-germany/?do=findComment&comment=2105330'>More sharing options...
k-hawinkler Posted September 6, 2012 Author Share #79 Posted September 6, 2012 K-H, that reflection effect depended a lot on the strength and placement of those light sources. As you can see, they are less intense in the second picture. There, there is one very strong point light to the left and low, that looks quite suspicious. You will probably only see the effect in really extreme situations, like this one: . Hi Lars, Is the photo in post #7 cropped? Thanks. Link to post Share on other sites More sharing options...
lars_bergquist Posted September 6, 2012 Share #80 Posted September 6, 2012 Hi Lars, Is the photo in post #7 cropped? Thanks. This is a full frame image, but from a M8. In this case we know of course that the effect was caused by the UV/IR filter in front of the lens. It was the reminiscence of this that caused me to post in the first place. Regards, LB Link to post Share on other sites More sharing options...
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