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#31
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Interesting Leica product announcements today ...
Chris Malcolm wrote,on my timestamp of 16/05/2012 9:38 AM:
bull****. Graion cannot be scanned with ANY vailable scanner. You need an electronic microscope to do that. Hang on! Did you ever do your own enlarging of B&W film? and colour as well. Cibachrome. If you did large enough blow ups you didn't bother focusing the enlarger by looking at image detail, you focused on the grain. Yup. Around 15X blow-up, THEN and only then I used the grain focuser to FURTHER magnify the image. And yes, the grain would be visible. With slide film and Cibachrome. The case pointed here was Tech Pan. Have you ever tried to focus Tech Pan using that technique? I can promise you a very big surprise. The same goes for Adox CMS20 and the "Rollei" clones. I've probably still got mine somewhere, along with my pneumatic bulb shutter releases and red filters :-) Still got mine. AND a microscope. |
#32
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Interesting Leica product announcements today ...
Peter Irwin wrote,on my timestamp of 16/05/2012 8:40 PM:
I would be astonished if anyone could even guess at the shape of individual grains based on what is visible in a grain focuser. And with Tech Pan I defy anyone to tell me when they are "seeing" grain... |
#33
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Interesting Leica product announcements today ...
David Dyer-Bennet wrote,on my timestamp of 16/05/2012 11:06 AM:
You can see grain quite clearly with moderate optical magnification; a few tens. No you CANNOT. Not with Tech Pan. THAT is the point. Stop changing the subject to match your "theories": it won't work. Are you on drugs? Since when is scanned size dependent on film ISO? What the hell are you smoking today? In a compressed format, including LZW-compressed TIFF, a noiser image will compress less well, and I *think* he may have been alluding to that. Ah, so a scan is a compressed TIFF image? Care to translate into the Queen's language? The stuff we saw in 11x14 optical prints from TRI-X is what was called "grain". That's an optical magnification of just over 10x. NO one was talking about Tri-x. Like I said: stop evading the subject. You're going to insist those are "grain clumps", right? I think I know this trick. They're universally referred to as "grain" by people describing the appearance of optical darkroom prints. NO they are not. |
#34
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Interesting Leica product announcements today ...
"David Dyer-Bennet" wrote in message ... At any given ISO I've tried (about 25-25600), digital is much less grainy/noisy than film. True for recent DSLR's of course, but not a universal truth as quoted. I guess you just haven't "tried" those that are not :-) True back to my first DSLR in 2002. Right, you should have said that then. Doesn't include many digital P&S though. Trevor. |
#35
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Interesting Leica product announcements today ...
On Tue, 15 May 2012 11:32:21 -0500, David Dyer-Bennet wrote:
Mxsmanic writes: David Dyer-Bennet writes: Far less subject to it than film was. Film isn't subject to thermal noise. Higher speed film has more grain. It doesn't it has more visible grain. It is just semantics really - most humans (including me) say what we think we mean but not always accurately. -- Neil Reverse ‘a’ and ‘r’ Remove ‘l’ to get address. |
#36
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Interesting Leica product announcements today ...
On 5/16/2012 6:03 AM, Noons wrote:
David Dyer-Bennet wrote,on my timestamp of 16/05/2012 11:06 AM: You can see grain quite clearly with moderate optical magnification; a few tens. No you CANNOT. Not with Tech Pan. THAT is the point. Stop changing the subject to match your "theories": it won't work. I have lots of Tech Pan negatives, so I was going to look at them with my excellent microscope. But what I found first was Tri-X. At 100x all I could actually resolve was grain clumps. At 400x (N.A. 0.75) I could see individual grains, and resolve some but not all. At 1000x (N.A. 1.30) I could resolve all the grains. There is a huge variation in grain size, and in clumpiness. Then I looked at Tech Pan. There are no clumps. And the grain size is far more uniform. I actually need 1000x to truly resolve the grains. It really can't be done at 400x, though that is perfectly adequate to see the individual grains. Resolution is clearly limited not by grain size but by emulsion thickness. But can you see the grain "structure" at 50x in Tech Pan? Yes, you can ... the fluctuation in density is easily seen. In fact, at background density you can see individual grains at 50x, but they are far from resolved. At ordinary density you see only fluctuations and the image itself. The bottom line is that at background density you should indeed be able, with a good enlarger lens ( at f/4) and a grain focuser, to actually focus on the grains themselves ... but they won't be resolved at all. You will be seeing little gray spots, not black. Doug McDonald |
#37
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Interesting Leica product announcements today ...
Noons writes:
David Dyer-Bennet wrote,on my timestamp of 16/05/2012 11:06 AM: You can see grain quite clearly with moderate optical magnification; a few tens. No you CANNOT. Not with Tech Pan. THAT is the point. Stop changing the subject to match your "theories": it won't work. No, the point is that in general grain is the limiting factor to "satisfactory" enlargement of film images. Are you on drugs? Since when is scanned size dependent on film ISO? What the hell are you smoking today? In a compressed format, including LZW-compressed TIFF, a noiser image will compress less well, and I *think* he may have been alluding to that. Ah, so a scan is a compressed TIFF image? Care to translate into the Queen's language? I was looking for something he might have meant by saying the scanned size depended on film ISO. One thing he might have meant is that the file size of the scanned image as stored on disk is larger for high-ISO films. The stuff we saw in 11x14 optical prints from TRI-X is what was called "grain". That's an optical magnification of just over 10x. NO one was talking about Tri-x. Like I said: stop evading the subject. You're going to insist those are "grain clumps", right? I think I know this trick. They're universally referred to as "grain" by people describing the appearance of optical darkroom prints. NO they are not. Um, look around you at the newsgroup, where many people are using it exactly that way. -- 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 |
#38
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Interesting Leica product announcements today ...
"David Dyer-Bennet" wrote in message ... Mxsmanic writes: Chris Malcolm writes: I think most DSLRs have menu-switchable long exposure noise reduction. Noise reduction also reduces image quality. Mostly, it *improves* image quality. Just out of curiosity, how does noise reduction know what is noise and what is fine detail in the photo? -- Ken Hart |
#39
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Interesting Leica product announcements today ...
Noons wrote:
On May 13, 3:20Â*am, Wolfgang Weisselberg Roger is yet another idiot with pretentions to scanning and film expertise. Â*I have 135mm tech pan that easily exceeds 24MP. Of course you should see *way* more than 24 MPix there. But the others are talking about 24x36mm film. 13,5 cm? As in "4x5 inch large format camera"? No. Read about film sizes and then comment. There is no "135mm" film size. There is "135" film and there is "35mm" film. So which is it? better? Â*I doubt it. Â*Yes, you should overscan. Â*But the extra pixels don't translate 1:1 into detail recovered. No one is talking about "overscan". Stay on topic. So photograph the microscope output. Really? Have you ever looked through a microscope at an entire film image? HOw big was that microscope? Any other pearls of idiocy to share? Are you an idiot? Or are you just trying hard to be one? Noone --- except you! --- says you're to photograph the whole image in one go under the microscope. So show your own proof. I have. Many times. Still do, in many places. Post the URL with the proof, that's less work than that handwaving of yours. Go ahead, do a drum scan ... Wish I could find one. Google for drum scan service. That isn't *that* complicated. Even you can manage that. -Wolfgang |
#40
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Interesting Leica product announcements today ...
On 2012-05-16 17:04 , K W Hart wrote:
"David Dyer-Bennet" wrote in message ... Mxsmanic writes: Chris Malcolm writes: I think most DSLRs have menu-switchable long exposure noise reduction. Noise reduction also reduces image quality. Mostly, it *improves* image quality. Just out of curiosity, how does noise reduction know what is noise and what is fine detail in the photo? Read the article beginning at: http://en.wikipedia.org/wiki/Noise_r...e_separat ion Then wonder how the various camera makers choose their strategies. They can use variations of most of the presented approaches (and likely some that aren't presented). The tough part is selecting the criteria - both fixed and criteria adapted to the content of the image. -- "A person with a new idea is a crank until the idea succeeds." -Samuel Clemens. |
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