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#11
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Interesting Leica product announcements today ...
"PeterN" wrote in message ... As I posted elsewhere, experiments are part of understanding a process. I used to mix my own developers, not to save money, which I didn't, but to learn how the different times and chemicals affected the images. Me too, along with thousands of other darkroom experiments. see no reason to trivialize his experiments. OK, not trivializing them, just surprised he didn't realise his findings were well known for well over half a century. Of course it's nice to see these things for yourself, but then there is no need to post as if it's a new discovery. However I'm not having a shot at him if he didn't already know, and I'm sure many others hadn't thought about it. I'm sure Prokudin-Gorsky knew about it however. Trevor. |
#12
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Interesting Leica product announcements today ...
"Trevor" writes:
"PeterN" wrote in message ... 1. Leica M Monochrom, with 18 MP black and white full frame sensor. No need for a Bayer pattern, no AA filter, no interpolation. Low noise up to ISO 10,000. Hmmm.... I can see already plans for a Photoshop add-on tool to merge together three images taken with R,G,B filters. Kinda like a modern autochrome @ 10000. It's easy enough to do without any special tool. I did it testing my theories about what caused certain background effects in the famous Prokudin-Gorsky photos (http://www.loc.gov/exhibits/empire/); my RGB merges are athttp://dd-b.net/ddbcms/2001/05/composite-color/. Interesting experiments. Why? I'm puzzled that he didn't realise people were doing this over 50 years ago with multiple exposures on color film using real filters, and the main aim was to get those colored ripples on water, or rainbow colored clouds etc. Who didn't realize what? Look, right up there in my quote, it says my doing it was inspired by seeing the Prokudin-Gorsky photos (from rather more than 50 years ago). To be more detailed, in discussion, we concluded that the interesting effects in the water and clouds were caused by the different exposure times for the color channels, but I wanted to really nail down that theory by reproducing the effect. So I did. That's the only reason to do it these days too, not try to eliminate it as David suggests. Obviously Prokudin-Gorsky would have seen this effect immediately and taken steps to avoid it when he didn't want it. However if Prokudin-Gorsky used a 3 lens projector, why could he not use a 3 lens camera and take simultaneous images? Are we sure he didn't? The image of the Nilova Monastery shows no colored ripples on the water or clouds at all, so either it's been very heavily doctored, or he did take simultaneous images. We don't have his exact camera. However, ALL the cameras we do have (or have writings about) from that period using a three-exposure system took them sequentially, not simultaneously. It does seem like simultaneous exposures were technically possible, but it doesn't seem that anybody actually did them. I haven't tried reconstructing the Nilova Monastery picture myself, but the individual scans are on the loc.gov site. That would quickly tell you if the colored ripples were removed in post-processing or were absent from the picture, at least. The water does NOT look absolutely flat. I could believe the clouds were moving slowly enough not to give visible fringing, but I'm not so sure about the water. -- David Dyer-Bennet, ; http://dd-b.net/ Snapshots: http://dd-b.net/dd-b/SnapshotAlbum/data/ Photos: http://dd-b.net/photography/gallery/ Dragaera: http://dragaera.info |
#13
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Interesting Leica product announcements today ...
"Trevor" writes:
"Savageduck" wrote in message news:2012051201594311272-savageduck1@REMOVESPAMmecom... Why? I'm puzzled that he didn't realise people were doing this over 50 years ago with multiple exposures on color film using real filters, and the main aim was to get those colored ripples on water, or rainbow colored clouds etc. That's the only reason to do it these days too, not try to eliminate it as David suggests. Obviously Prokudin-Gorsky would have seen this effect immediately and taken steps to avoid it when he didn't want it. However if Prokudin-Gorsky used a 3 lens projector, why could he not use a 3 lens camera and take simultaneous images? Are we sure he didn't? The image of the Nilova Monastery shows no colored ripples on the water or clouds at all, so either it's been very heavily doctored, or he did take simultaneous images. It is thought Prokudin-Gorsky probably used a personally customized versions of the earlier Adolf Miethe camera produced by Bermpohl Company. That camera doesn't take simultaneous images, so the question remains why no color artifacts are visible in the Prokudin-Gorsky photo's. If they have in fact been doctored to the extreme, it should have beeen stated what was done IMO. In many of the photos the color artifacts ARE visible. Just a few aren't; those could be good luck with weather, fast operation of a sequential camera, or perhaps extensive post-processing. As I said, the original scans are downloadable from the LOC site, it's easy to check if the artifacts are present before post-processing. -- David Dyer-Bennet, ; http://dd-b.net/ Snapshots: http://dd-b.net/dd-b/SnapshotAlbum/data/ Photos: http://dd-b.net/photography/gallery/ Dragaera: http://dragaera.info |
#14
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Interesting Leica product announcements today ...
"David Dyer-Bennet" wrote in message ... We don't have his exact camera. However, ALL the cameras we do have (or have writings about) from that period using a three-exposure system took them sequentially, not simultaneously. It does seem like simultaneous exposures were technically possible, but it doesn't seem that anybody actually did them. I can't see how you can avoid color fringing on water and clouds without simultaneous exposure or serious post processing. I haven't tried reconstructing the Nilova Monastery picture myself, but the individual scans are on the loc.gov site. That would quickly tell you if the colored ripples were removed in post-processing or were absent from the picture, at least. The water does NOT look absolutely flat. I could believe the clouds were moving slowly enough not to give visible fringing, but I'm not so sure about the water. It's very rare the clouds will stay still long enough either for the time needed to change filters and take 3 exposures without some fringing either. I'm just saying, all these things would have been well known to P-G through experience. IF the Nilova photo and others are not heavily doctored, I'm betting he used a 3 lens camera, or 3 cameras simultaneously. Of course he would only have done that after using a single camera/lens and discovering the problem in the first place. Trevor. |
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