Film scanning noise.

thebigsky

I bought a Minolta Dimage film scanner some months ago and have been attempting, when time allows, to scan my old picture collection.

I'm finding that all the scans seems to have lots of colour noise, is this a problem inherent with scanning 35mm negatives or should I expect better quality scans from this source material?

I seem to have exhausted all the various scan options, and don't seem to be able to extract the quality of image I was expecting. If you had a good exposure on 35mm negative and you scanned it, how large would you expect to be able to print it at reasonable quality?

This image for instance was shot on Fujicolour ISO 100 film with a Minolta X300. I've had to apply lots of noise reduction in PS which has rendered the details and sharpness only suitable for display at this size and a maximum 6" x4 " print.



Any help would be appreciated.

Charlie

01af

thebigsky wrote:

I'm finding that all the scans seems to have lots of colour noise, is this a problem inherent with scanning 35-mm negatives or should I expect better quality scans from this source material?

Yes, and yes. The problem *is* inherent to scanning film. Still, you should be able to do better.

Many confuse grain aliasing with noise or grain. Grain aliasing occurs when the scanner's regular pixel grid and the film's irregular grain pattern appoximately fall within the same order of magnitude. With typical 35-mm scanners' resolutions (2,800 - 4,000 ppi), this often is the case. Grain aliasing creates an artifact which usually looks like excess grain or noise but actually is neither. To make things worse, real noise also is prone to occur in film scanning, particularly when scanning colour negatives.

There are a few tricks to fight grain aliasing ... search the Internet for 'scanner,' 'scanning,' 'film,' and 'grain aliasing.'

-- Olaf

ziggy53

Charlie,

I have a Minolta DiMAGE Scan Dual IV, and what Olaf is telling you is true.

Neat Image is particularly effective to combat general excess grain, IMHO.

http://www.neatimage.com/

Another thing you should be aware of is that film scanners use a type of condenser light that may not be as pleasant for photos with smooth continuous tones. The "Scanhancer" is a diffusor designed to fit over the negative/slide and it should help provide smoother tonality, at the expense of contrast (somewhat). I don't think they have a product for all scanners.

http://www.scanhancer.com/index.php?art=15&men=15

(Note that I don't have one, but others seem to like them.)


You may notice some "pepper-grain", light and dark pixels appearing spontaneously in the image, again most noticable in smooth-toned areas of the image. This is the grain aliasing Olaf spoke of, and I found that the free Polaroid "Dust and Scratch Removal" software works pretty well to reduce the effect. Run it after general noise reduction software. You may also need to run it against a new layer, so you can selectively preserve detail where needed, or even blend 2 layers.

http://www.polaroid.com/service/software/poladsr/poladsr.html

All in all, I was able to achieve images very similar to a 6MP digital camera, again, IMHO.

ziggy53

ziggy53

Here is a scan from 2004 from a Fed5 and Industar 50mm lens (Tessar design) at f2.8.



... and here is a link to the full resolution image (big file):

http://ziggy53.smugmug.com/photos/89179245-D.jpg

thebigsky

Wow, thanks guys, it seems my dream of quickly scanning all my old images will remain that, looks as though I have a lot of work ahead of me.

I'll go away and digest all the information you've both provided and think again about my approach.

Charlie

DavidTO

One way to get rid of chroma noise is to use LAB mode.

In LAB, select both the A and B channels, and apply a guassian blur to them, just enough to eliminate the noise. This affects the image very minorly, I doubt you'll even see it, since the L channel holds all the detail. Give it a shot on the images you're not happy with, and see how it goes.

This is assuming you have the full Photoshop, NOT Elements, which has no LAB mode. Not sure about other applications, YMMV.

DavidTO

In the future, also, when you're trying to show noise to us, it'd be best if you included a 100% crop, so we can see the detail. The image you posted is pretty much useless for evaluating noise.