Noise from negative scans

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Can someone help me? I have just invested a considerable amount of money in a Minolta Scan Elite. The reviews were good, the specification good and I thought this would be the ideal transition to digital.The software is impressive and easy to install and it was up and running in no time.

I decided to compare scans made on an old, cheap flatbed scanner at 600dpi with scans on the Elite at 2820dpi. I used the same image for both - a Kodak Gold ISO 200 35mm negative with its corresponding 6" x 4" print from a high street lab. What a disapointment! My flatbed scan had good continuous tone, good colour rendition, could be zoomed a long way before seeing pixels and jagged edges and had no discernable noise. In comparison even with maximum settings used of 2820 dpi, 16bit colour, 16X multiple scanning digital ICE...... the results were inferior to my cheap flatbed. There was considerable noise in the picture, I could not zoom to anything like as much before pixels showed and even the colour was out. After a considerable amount of tweaking I managed to get the colour correct again but the other problems of noise and resolution remain.

Am I doing something wrong? Or could it be that the flatbed route is the best. If this is so I think I will sell the film scanner and stick with the flatbed! .

Scans are also much quicker with the flatbed and I could have turned up the resolution on it even higher but this would have used interpolation and I prefer to let Photoshop do this. I expect the D.Max is lower on the flatbed but this is of little relevance for most work. If it became an issue I might get a new flatbed with higher optical resolution and greater D.Max

Should I give up on negative scanning or can somebody point out what I am doing wrong?

Dave Radcliffe

-- Dave Radcliffe (dmradcliffe@hotmail.com), July 03, 2000

Answers

You must be doing something wrong, are you sure you've got the maximum res set on the Scan Elite? 600dpi from a 6x4 print will give you an 8megapixel file, and the maximum res from your scan elite should give you over 10megapixels, so there shouldn't be visible jaggies and pixels at a smaller zoom ratio than the flatbed. Are you getting 30megabyte files from the film scanner?

My cheaper and less well respected Acer ScanWit gives me excellent scans from negatives, easily beating my 600x1200 dpi/36 bit flatbed scanner, in terms of sharpness, and colour and shadow detail, even against scans from 10"x8" prints.

There can be a problem with "aliasing" of the film grain with the pixels of the digital image, and this isn't easily cured, except by using slower, more finely grained film, or throwing the scanner focus off slightly, if possible. I don't know the scan elite. If it has a manual focus control, try blurring the image very slightly and see if that helps.

I've put together a few tips specifically aimed toward using my scanner, but they might be of some use. Look here

-- Pete Andrews (p.l.andrews@bham.ac.uk), July 03, 2000.


Pete raises some good points.

I recently bough a Nikon LS2000, and had found scans from negs varied greatly depending upon the film type being used (it's grain size in particular).

Try scanning without the 16x multi-scan. It is only really useful for getting detail from the shadow areas. On a negative the dark areas are inverted so you are getting a benefit in the light areas. The multi-scan can also lead to clumping of pixels in grainy films.

Are you using any weird settings in the sharpening tools?, again this can lead to exagerated noise in shadows.

Before losing heart completely, try the scaner on different films, and slides. The best results seem to be from a good fine grained slide film rather than negative.

Above all else keep experimenting, it took me approx 2-3 weeks before i could consistently get results that i was happy with.

good luck

Martin

-- Martin Ellis (inca@globalnet.co.uk), July 04, 2000.


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