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#1
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Photoshop grayscale problem
Hi Everyone,
I know this isn't a Photoshop newsgroup, but I'm hoping that someone here might have encountered a similar problem that I describe below when trying to digitize a 4x5 black/white negative. Any Photoshop gurus -- HELP, please, if you can. I'm a relative Photoshop neophyte... I took a black/white negative and scanned it on my Epson V-700 scanner. No matter whether I scanned in 8-bit or 16-bit mode, when my scanned image comes up in Photoshop, the sky brightness, which varies greatly over this highly vignetted photographic image, shows definite brightness "steps" from darker to brighter. This sky brightness range is very compressed compared to the image's whole brightness range. In other words, there is black in part of the image, and white in another part. The sky varies from one shade of gray to a slightly brighter shade. And these "quantization steps" make the resulting image look TERRIBLE (at least in the sky portion of the image). What can I do about this? I'd rather not add noise, since the image right now looks wonderfully smooth. Please help! I'm a relative Photoshop neophyte... Thanks, Scott |
#2
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Photoshop grayscale problem
On Mar 29, 10:30 pm, "Scott Speck" wrote:
Hi Everyone, I know this isn't a Photoshop newsgroup, but I'm hoping that someone here might have encountered a similar problem that I describe below when trying to digitize a 4x5 black/white negative. Any Photoshop gurus -- HELP, please, if you can. I'm a relative Photoshop neophyte... I took a black/white negative and scanned it on my Epson V-700 scanner. No matter whether I scanned in 8-bit or 16-bit mode, when my scanned image comes up in Photoshop, the sky brightness, which varies greatly over this highly vignetted photographic image, shows definite brightness "steps" from darker to brighter. This sky brightness range is very compressed compared to the image's whole brightness range. In other words, there is black in part of the image, and white in another part. The sky varies from one shade of gray to a slightly brighter shade. And these "quantization steps" make the resulting image look TERRIBLE (at least in the sky portion of the image). What can I do about this? I'd rather not add noise, since the image right now looks wonderfully smooth. Please help! I'm a relative Photoshop neophyte... Thanks, Scott Are you scanning it in color then converting it to black and white in photoshop? It sounds like a moot point but you might what to try it. A really good read on photoshop tips and tricks is "the photoshop book" for digital photographers by scott kelby. Earl |
#3
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Photoshop grayscale problem
On Mar 29, 8:30 pm, "Scott Speck" wrote:
Hi Everyone, I know this isn't a Photoshop newsgroup, but I'm hoping that someone here might have encountered a similar problem that I describe below when trying to digitize a 4x5 black/white negative. Any Photoshop gurus -- HELP, please, if you can. I'm a relative Photoshop neophyte... I took a black/white negative and scanned it on my Epson V-700 scanner. No matter whether I scanned in 8-bit or 16-bit mode, when my scanned image comes up in Photoshop, the sky brightness, which varies greatly over this highly vignetted photographic image, shows definite brightness "steps" from darker to brighter. This sky brightness range is very compressed compared to the image's whole brightness range. In other words, there is black in part of the image, and white in another part. The sky varies from one shade of gray to a slightly brighter shade. And these "quantization steps" make the resulting image look TERRIBLE (at least in the sky portion of the image). What can I do about this? I'd rather not add noise, since the image right now looks wonderfully smooth. Please help! I'm a relative Photoshop neophyte... Thanks, Scott I scan thousands of medium format b/w negatives as part of my job (electron microscope tech). If you could post a photo of your results it might be really helpful in obtaining advice. Or email me and I will look at what you are dealing with. -- Nicko |
#4
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Photoshop grayscale problem
Scott Speck wrote:
Hi Everyone, I know this isn't a Photoshop newsgroup, but I'm hoping that someone here might have encountered a similar problem that I describe below when trying to digitize a 4x5 black/white negative. Any Photoshop gurus -- HELP, please, if you can. I'm a relative Photoshop neophyte... I took a black/white negative and scanned it on my Epson V-700 scanner. No matter whether I scanned in 8-bit or 16-bit mode, when my scanned image comes up in Photoshop, the sky brightness, which varies greatly over this highly vignetted photographic image, shows definite brightness "steps" from darker to brighter. This sky brightness range is very compressed compared to the image's whole brightness range. In other words, there is black in part of the image, and white in another part. The sky varies from one shade of gray to a slightly brighter shade. And these "quantization steps" make the resulting image look TERRIBLE (at least in the sky portion of the image). What can I do about this? I'd rather not add noise, since the image right now looks wonderfully smooth. Please help! I'm a relative Photoshop neophyte... Thanks, Scott Check that Photoshop is not converting the image to 8-bit mode. Look at Image\Mode - Grayscale should be ticked, and at the bottom of the dropdown menu, 16-bit should be ticked. Colin D. -- Posted via a free Usenet account from http://www.teranews.com |
#5
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Photoshop grayscale problem
On Mar 29, 10:30 pm, "Scott Speck" wrote:
Hi Everyone, I know this isn't a Photoshop newsgroup, but I'm hoping that someone here might have encountered a similar problem that I describe below when trying to digitize a 4x5 black/white negative. Any Photoshop gurus -- HELP, please, if you can. I'm a relative Photoshop neophyte... I took a black/white negative and scanned it on my Epson V-700 scanner. No matter whether I scanned in 8-bit or 16-bit mode, when my scanned image comes up in Photoshop, the sky brightness, which varies greatly over this highly vignetted photographic image, shows definite brightness "steps" from darker to brighter. This sky brightness range is very compressed compared to the image's whole brightness range. In other words, there is black in part of the image, and white in another part. The sky varies from one shade of gray to a slightly brighter shade. And these "quantization steps" make the resulting image look TERRIBLE (at least in the sky portion of the image). What can I do about this? I'd rather not add noise, since the image right now looks wonderfully smooth. Please help! I'm a relative Photoshop neophyte... Thanks, Scott Make sure you are in greyscale not black and white, the latter is a 2 bit conversion for text, and says what it means, black and white. But you shouldn't have the 8 or 16 bit versions with B&W selected, unless you are setting the bit depth and then the mode. I have done quite a few 4x5 negs, greyscale and color on a V700 and never had that problem. I don't like B&W negs scanned in color on this scanner, so I have been scanning in 16 bit greyscale and the results have been great. They print very well on my Cannon iPF5000. Tom |
#6
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Photoshop grayscale problem
On Mar 29, 8:30 pm, "Scott Speck" wrote:
Hi Everyone, I know this isn't a Photoshop newsgroup, but I'm hoping that someone here might have encountered a similar problem that I describe below when trying to digitize a 4x5 black/white negative. Any Photoshop gurus -- HELP, please, if you can. I'm a relative Photoshop neophyte... I took a black/white negative and scanned it on my Epson V-700 scanner. No matter whether I scanned in 8-bit or 16-bit mode, when my scanned image comes up in Photoshop, the sky brightness, which varies greatly over this highly vignetted photographic image, shows definite brightness "steps" from darker to brighter. This sky brightness range is very compressed compared to the image's whole brightness range. In other words, there is black in part of the image, and white in another part. The sky varies from one shade of gray to a slightly brighter shade. And these "quantization steps" make the resulting image look TERRIBLE (at least in the sky portion of the image). What can I do about this? I'd rather not add noise, since the image right now looks wonderfully smooth. Please help! I'm a relative Photoshop neophyte... Thanks, Scott I am not familiar with that scanner. Does it have a transparency/ negative scan function, or are you scanning it as a print (reflective medium)? Scanning negatives is a real problem for reasons to be explained below. For this reason, scanners with a built-in negative scan function contain special software. In addition to inverting the tones, it also handles the dynamic range and strange contrasts I am assuming you do not have a scanner with a light source in the lid, but are using the white screen in the cover. Now, a good negative already has a wide dynamic range. When scanning a transparency using the white lid, the light passes through TWICE! The already high dynamic range is again increased greatly! This screws up the dynamic range processing (curves function) of the normal print scanning software. If the scanner does not have a RAW function, you need to seriously get into the scanner options and play with the contrast and brightness settings. Best is to use a scanner already set up for scanning transparencies and negs (i.e, one with a light source in the cover. |
#7
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Photoshop grayscale problem
Scott Speck wrote:
I took a black/white negative and scanned it on my Epson V-700 scanner. No matter whether I scanned in 8-bit or 16-bit mode, when my scanned image comes up in Photoshop, the sky brightness, which varies greatly over this highly vignetted photographic image, shows definite brightness "steps" from darker to brighter. This sky brightness range is very compressed compared to the image's whole brightness range. In other words, there is black in part of the image, and white in another part. The sky varies from one shade of gray to a slightly brighter shade. And these "quantization steps" make the resulting image look TERRIBLE (at least in the sky portion of the image). What can I do about this? I'd rather not add noise, since the image right now looks wonderfully smooth. Please help! I'm a relative Photoshop neophyte... Make sure you have the auto controls off on the scanner. Set the manual controls carefully. Scan in 16 bit. And then hope. It may well be that the maximum density of these negatives (which, remember, is the area representing the *brightest* parts of the scene; they're *negatives*) is down near or beyond the limits of that scanner. Flatbed scanners don't do the best jobs on film, especially slides and B&W negs, for this among other reasons. And good luck. (The term for what you're seeing is "posterization", if I'm understanding your description correctly.) |
#8
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Photoshop grayscale problem
Make sure your monitor isn't set for 256 colors or 16-bit color. You want to
use 24-bit or 32-bit color for your monitor color settings. Especially when working with Photos. =(8) |
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