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Software for Converting Negative images to Color

Thomas Penrose , Aug 30, 2000; 12:41 p.m.

I just bought a Nikon 990 Coolpix digital camera, and am quite amazed by how well it dupes slide film using my Bencher copystand/light table. I am even liking the results better in many cases than what I achieved with my Polaroid Sprintscan 35 Plus 2700dpi slide scanner. The one drawback is not being able to convert the dupes of color negatives into positives using Photoshop due to the orange base of color negative film. Inverted images are totally blue. Is there software available that can do this? (I am assuming that it is a function of software rather than hardware). Thanks.


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Bob Atkins , Aug 30, 2000; 02:15 p.m.

I'd assume you can do it via color corrections in Photoshop. Since I'm not a Photoshop user I can't comment on the exact procedure, but in my software adjustment of gamma for each of the R, G and B channels, plus overall color correction would be the way I'd go.

chuong doan , Aug 30, 2000; 02:18 p.m.

I cannot believe that the you are getting better results using a copystand and Coolpix than your sprintscan! In what ways are they better? This is no flame, I'm just very curious!

I think scanning software takes care of the color cast resulting from emulsion bases. You may be able to use Hamrick's Vuescan software to correct your scans- it scans raw images into a Tiff file and then corrects them after you tell it what film you were using etc. I think there is an option for scanning from file actually. www.hamrick.com good luck!

D. Chan , Aug 30, 2000; 03:06 p.m.

What I have done in the past is to use the white eyedropper tool in Photoshop to select the clear orange mask are which will convert it to white and then invert. Don't think it's the most accurate way but it's simple.

andrew schank , Aug 30, 2000; 03:11 p.m.

The software that came with my Epsom 636 scanner has the negative inversion set up with it. It is just a basic Adope business edition packaged software. It works pretty well, but not as good as scanning slides. ( I have the transparancy adapter) I find I have to punch the contast up a lot to get the images to look close to real prints from the negatives.

Thomas Penrose , Aug 30, 2000; 03:26 p.m.


This link has an example of one of the 35mm slides I duped using the Nikon 990. It shows about 80% of the negatives surface area, and is made much smaller than the original file size of 8mb. It is also compressed as a level 4 jpeg. It is not quite as sharp as the 2700dpi scans I got of the same image using my Polaroid Sprintscan, but I believe it is better in some ways. It shows the layering of the paint better, and just looks more natural to me. My Sprintscan scans of oil painting slides always had a chalky effect to the color, and the texture looked unnatural. These 990 dupes just look more lively to me, and more accurate not only in terms of color, but overall tonality.

Thomas Penrose , Aug 30, 2000; 04:06 p.m.

Using VueScan, I was able to "scan from disk" using one of the pre-existing color negative dupes I had made with the Nikon 990. With the "Media Type" setting of Vuescan set to "Color Negative" it did in fact convert the negative .tif image to a positive, but the positive was the same heavily bluish conversion one gets in Photoshop5 when you use the "invert" command. So, while I am sure that VueScan likely does a fine job of converting a color negative while a scanning operation is taking place, something seems to not be happening when you are trying to convert a color negative image already saved to disk.

chuong doan , Aug 30, 2000; 04:55 p.m.

It may be the you're getting some kind of cast from your Coolpix, making the emulsion seem more "orange" than usual. My choice then, would be to delve into curves and do a manual correction to your taste. If you have no luck in RGB, use CMYK as most pros should be using and cut C.

Brian Willis , Aug 30, 2000; 05:08 p.m.

The basic method in photoshop to convert a scan of a negative to a positive is: (1) Sample the orange mask of the negative (i.e., use the eye dropper to grab the color of the mask from the very edge of the film where it did not get exposed), (2) Make a new layer with the color of the orange mask (i.e., after you make a new layer, select all and use the paint can with the sampled color of the mask) (3) Invert the color of this new layer and then subtract this layer from the layer with the negative; (4) Split and equalize each of the color channels separately, (4) Merge channels and then invert the negative to a positive. Really only takes a short time after you do it once. You need to get the mask color for each type of film, but once you do one image of a given type of film you can store the steps as an action that takes only a few seconds.

Scott Eaton , Aug 30, 2000; 05:59 p.m.

{{My Sprintscan scans of oil painting slides always had a chalky effect to the color, and the texture looked unnatural}}

A local Photo store has a Sprintscan set up for their customers to use free of charge, and after an hour or so of goofing around with the thing I gave up on scans from trans. Same problems you observed.

Even though much lower rez, your Coolpix is going to by default handle the dynamic range of a trans better than the scanner, so I'm not surprised.

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