PDA

View Full Version : Need recommendations to reduce noise


bham
Dec-05-2005, 10:46 PM
I have many negatives that I am in the process of scanning. Once I have the image scaned they look noisy especially as you view them at larger sizes. Does anyone has a step by step process they can recommend or a combination of filters that can help.

Thanks for any help and suggestions.

Here are a few examples of what I am getting from the scanner.

http://mcleod.smugmug.com/gallery/973504

marlinspike
Dec-05-2005, 11:44 PM
Use better film
no seriously, (though that does help) I found that the PS despeckle filter (filter>noise>despeckle) works well on film grain. However, I also found that while film grain is a problem on the screen it's not much of a problem in prints (I have some 8x10 prints from iso 1600 fuji press in my room at home and while they look noisy as all get out on a screen there's basically 0 noticeable noise in the prints).

cletus
Dec-06-2005, 06:17 AM
I've got a book with a fairly decent section on noise removal. Unfortunately, it's been a long time since I read the section and I don't have the book with me. I'll re-read the section this evening and see if there's anything that would apply to film grain removal.

rutt
Dec-06-2005, 06:29 AM
If you have CS2, use surface blur. Use on a separate layer in LAB. Tune the parameters to preserve as much detail as possible and still remove your noise ("threshold" here works the opposite as in USM, higher values attack more of the image, lower values consider more subtle transitions to be surfaces, and thus not blurred.) Check to see if the noise is isolated on one or two of the channels. If you have good luck it will be color noise and isolated from the L channel. If so, blur away; you won't lose detail. If it's L channel nose, you'll want to adjust blending options when you are done, opacity and the blend-if sliders, to isolate the blur to parts of the image where it belongs.

bham
Dec-06-2005, 03:08 PM
Use better film
no seriously, (though that does help) I found that the PS despeckle filter (filter>noise>despeckle) works well on film grain. However, I also found that while film grain is a problem on the screen it's not much of a problem in prints (I have some 8x10 prints from iso 1600 fuji press in my room at home and while they look noisy as all get out on a screen there's basically 0 noticeable noise in the prints).
I don't shoot film anymore, but I have a ton of stuff I am in the process of digitizing with a film scanner.

Yeah maybe I am being to picky. I did take a 35mm scan from a ISO 400 negative and print a 20 x 30 and unless you are looking for it you can't really tell.

But some good ideas thanks. I will try them. I don't have CS2 but I get a sense of how you are trying to do it. I will try multiple layers with different filters and blends and see what helps.

Mark Horn
Dec-06-2005, 08:51 PM
NeatImage has a free basic version of their noise reducing software. JPEG only in the free but they also have (at a cost) a plug in version for PS, which is all formats. It does amazing things to noisey shots.