Comments on: Sharpening photos in the darkroom http://photocritic.org/darkroom-unsharp-mask/ The Photocritic DIY photography projects blog Wed, 07 Jan 2009 21:08:00 +0000 http://wordpress.org/?v=2.7 hourly 1 By: artman http://photocritic.org/darkroom-unsharp-mask/#comment-262218 artman Sat, 31 May 2008 06:32:35 +0000 http://www.photocritic.org/?p=952#comment-262218 great post:) great post:)

]]> By: Kent http://photocritic.org/darkroom-unsharp-mask/#comment-261873 Kent Wed, 28 May 2008 14:51:10 +0000 http://www.photocritic.org/?p=952#comment-261873 I used to do color separations on 16X20 sheet film. I used a film made for the purpose, Kodak 4570 Pan Masking Film. It was different in that it had no anti-halation coating. (There is a dark coating on the back of most film to keep light from reflecting back up through the sensitive layers after it has come through them. It would create halos around points of light.) The film was exposed through the base, with the emulsion on the bottom with one or two exposures through color filters. Then in the next step it was placed on a sheet of separation film in the same position using register pins, and the separation film was exposed through a color filter. It is called unsharp masking because it would sound wrong to call it blurry or dull. The masking film was used mainly for color correction for the four color process. The printing process used for color uses 4 inks, cyan, magenta, yellow, and black. The 3 colors are not perfect, and they act like there is a some mixture of the other colors in them. for example, the yellow should absorb only blue light, but it absorbs a small amount of green light, like it was mixed with some magenta ink. So the mask is made with a green filter. That makes the final yellow film lighter in areas where there is magenta ink. This is more than you ever wanted to know about stone-age color reproduction, but once I got started thinking about it I just had to explain. I used to do color separations on 16X20 sheet film. I used a film made for the purpose, Kodak 4570 Pan Masking Film. It was different in that it had no anti-halation coating. (There is a dark coating on the back of most film to keep light from reflecting back up through the sensitive layers after it has come through them. It would create halos around points of light.)
The film was exposed through the base, with the emulsion on the bottom with one or two exposures through color filters. Then in the next step it was placed on a sheet of separation film in the same position using register pins, and the separation film was exposed through a color filter.
It is called unsharp masking because it would sound wrong to call it blurry or dull.
The masking film was used mainly for color correction for the four color process. The printing process used for color uses 4 inks, cyan, magenta, yellow, and black. The 3 colors are not perfect, and they act like there is a some mixture of the other colors in them. for example, the yellow should absorb only blue light, but it absorbs a small amount of green light, like it was mixed with some magenta ink. So the mask is made with a green filter. That makes the final yellow film lighter in areas where there is magenta ink.
This is more than you ever wanted to know about stone-age color reproduction, but once I got started thinking about it I just had to explain.

]]> By: Udi Tirosh http://photocritic.org/darkroom-unsharp-mask/#comment-254791 Udi Tirosh Sun, 11 May 2008 17:21:35 +0000 http://www.photocritic.org/?p=952#comment-254791 Great post Haje, It it always nice to know what they did in the pre PS days. Do you have any pictures of the process to share? - udi Great post Haje,
It it always nice to know what they did in the pre PS days.
Do you have any pictures of the process to share?
- udi

]]> By: photographyVoter.com http://photocritic.org/darkroom-unsharp-mask/#comment-244527 photographyVoter.com Sun, 20 Apr 2008 03:53:46 +0000 http://www.photocritic.org/?p=952#comment-244527 <strong>Sharpening photos in the darkroom...</strong> Ever wonder why it's called the "Unsharp Mask" rather than the "Sharp Mask"? Take a step back into the darkroom and you'll see where term originated from.... Sharpening photos in the darkroom…

Ever wonder why it’s called the “Unsharp Mask” rather than the “Sharp Mask”? Take a step back into the darkroom and you’ll see where term originated from….

]]> By: Sadegh http://photocritic.org/darkroom-unsharp-mask/#comment-244154 Sadegh Fri, 18 Apr 2008 17:24:26 +0000 http://www.photocritic.org/?p=952#comment-244154 Hi. Thanks for the article(s). ;) We have a website containing professional articles about photography: www.akkasee.com Yes, it's persian, and can I use (translate) some of your articles, of course with your name? Hi.

Thanks for the article(s). ;)
We have a website containing professional articles about photography: http://www.akkasee.com
Yes, it’s persian, and can I use (translate) some of your articles, of course with your name?

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