Yes, i t makes sense to me. I also scan a lot of B/W negatives, and once had the following thought: some of my negatives are Ilford PAN Fplus that I developped in a mild Perceptol dilution.
The negs are fine, but slightly pink. not the emulsion but the acetate material. So I thought that if I would scan in RGB (without reversing) this "Pink channel" would have the weakest contrast in it. also if there is none-emulsion grain/dust/scratches they would be mostly out of focus in the scanner, and possibly emphesised or weakened in one of the RGB-channels.
Now I did a lot of experiments with this in mind, but up till now there’s not a dramatic gain in quality…
Perhaps one of the others comes up with a brilliant idea, until then I keep experimenting. Rob
Documentation for my Epson flatbed says to scan through the film base. I’ve found that shooting through the emulsion, and flopping in software, frequently does a better job, especially if there is a lot of base fog. A dedicated film scanner, with a less-diffuse light source, would likely not be as sensitive.
Yes, if your negs have a coloration, you can use RGB to explore available contrast differences.
Older negs may have been processed in Pyro, which stains the film, and the stain becomes part of the density. The graded papers are only blue sensitive, so a brownish stain prints with a surprising density and contrast on those papers. On VC papers, stained negs give fits for proper selection of the contrast filters.
So, in scanning, it would be worth while if you see a definite deepening of the stain with an increasing density to go to RGB. Other films may have only the base a given color, and they will not respond the same way. I have some Panatomic X negs that have a greenish cast to them, but it doesn’t seem to affect the contrast. (except that the cast raises slightly the Dmin of the film.)
May be I didn’t make myself so clear.
I want neutral greys – I am not interested in whatever stain there might be in the negative. What I am wondering is if there is any advantage (qualitywise) in scanning RGB (desaturated) instead of greyscale.
One good reason for scanning in RGB is that when you scan in grayscale, most scanners typically use just one channel to make the grayscale. By scanning with all three channels and then converting to grayscale, you average the different noise levels of the three channels instead of having to live with the noise of a single channel.This results in lower noise levels in the highlights, where you would typically see problems in neg scans.
…most scanners typically use just one channel to make the grayscale.
Is that true? I really don’t know. I had assumed that most scanners were dumb, and relied on software in the computer to do most of the clever parts.
most scanners typically use just one channel to make the grayscale
I never heard of that.
But never to old to learn, I scanned an IT8 cal. target as if it were a B/W neg, and it is certainly scanned using the RGB channels. Further testing revealed that it averages like PS’s "desaturate" does.
However I still feel some advantages in scanning B/W negs in colour reversal mode, though I don’t know yet what the advantage is. (very scientific, isn’t it?)
Rob
Thanks for the input so far.
Anybody else?
RGB will give you the channels to adjust for fine tuning the image grayscale will not, but larger file size with the RGB.
Bigcat
s.com wrote:
Thanks for the input so far.
Anybody else?
____________________________________________________________ ___________________ Posted Via Uncensored-News.Com – Accounts Starting At $6.95 –
http://www.uncensored-news.com <><><><><><><> The Worlds Uncensored News Source <><><><><><><><>
I would go with RGB. There is so much more contrast that you can get by combining the channels than with just one K channel.
I don’t want contrast when I’m scanning film. There’s so much range in film, that I want to capture as much as possible–you can bump it up later in software.
If grayscale scanning is truly RGB (I dunno), but desaturated later, the best choice would be the one that could separate the tones better. The scanner software will likely see more bits than Photoshop.
All I know is that when I take my files to Walgreen’s to print. It has to be RGB. Walgreen’s can not print CMYK or Grayscale!
Ranzy
wrote in message
Thanks for the input so far.
Anybody else?
I also scan a lot of BW negs as well as slides, on a NIkon Supercoolscan 4000 ED and my thoughts are that if its a BW neg I scan in greyscale. It scans quickly and gives you a small file.
If your scans are going to be 4-col litho printed, then they will only go on the black plate anyway, so no problem. (Unless they are duotones or something in which case you would convert to CMYK)
If you want to print them to a colour inkjet (Epson-type) printer, then go Image|Mode|RGB and print them. Gives a much smoother tonal range than just greyscale (which again will only use the black ink) plus you can use Image|Adjust|Colour Balance to ‘tint’ your photo any way you choose. Its really easy.
I believe there is a difference between scanning in grey or RGB on the way the scanner ‘reads’ the image and I think you do get a *slightly* better result if you scan RGB then desaturate, but for me it doesn’t make such a big difference. I’d rather scan quickly and have smaller files with less processing.
