Scanning grayscale or RGB?

[pco98]

Hello all,

I am scanning with a Konica Minolta Elite 5400 II using Vuescan. I have done all my colour slide using ProPhoto. Now I have some silver halide film (Kodak T-Max 100 and 400) of which Vuescan includes some useful grayscale profiles.

Should I scan in 16bit grayscale or RGB?

The former results in much smaller filesizes which is nice but is it better to scan in RGB (bigger files) and use monochrome mixer in PS for monochrome work. What if I just converted the smaller grayscale scans in PS to RGB and then used monochrome mixer that way.

One last thing, if I do scan with grayscale PS asks for a profile when first opened and suggests grayscale dot gain 20%. What is the 'best' profile to pick for grayscale? And if I scan in RGB does it matter what profile I pick out of the big three (sRGB, Adobe RGB, ProPhoto RGB)

Thanks in advance,

Ross

[bob mccarthy]

Hello all,

I am scanning with a Konica Minolta Elite 5400 II using Vuescan. I have done all my colour slide using ProPhoto. Now I have some silver halide film (Kodak T-Max 100 and 400) of which Vuescan includes some useful grayscale profiles.

Should I scan in 16bit grayscale or RGB?

The former results in much smaller filesizes which is nice but is it better to scan in RGB (bigger files) and use monochrome mixer in PS for monochrome work. What if I just converted the smaller grayscale scans in PS to RGB and then used monochrome mixer that way.

One last thing, if I do scan with grayscale PS asks for a profile when first opened and suggests grayscale dot gain 20%. What is the 'best' profile to pick for grayscale? And if I scan in RGB does it matter what profile I pick out of the big three (sRGB, Adobe RGB, ProPhoto RGB)

Thanks in advance,

Ross

travelboundphotography.com
[{POST_SNAPBACK}][/a]

Ross, scanning a B&W negative in RGB does not add in color allowing the channel mixer to work as a digital filter. The "only" reason to scan in rgb, is one of the color layers is sharper than the others. On some consumer scanners, one layer is often sharper. One would then discard the other color layers.

[a href=\"http://www.largeformatphotography.info/1800F-bw.html]http://www.largeformatphotography.info/1800F-bw.html[/url]

My N5000 does not show this effect, nor does the creo and cezanne I occasionally use.

As far as gamut, in B&W there from a practical viewpoint, there is none.

Bob

[David Good]

Generally speaking there is no advantage to outputting 48 bit files from b&w film unless you are using a third party plug-in that requires an RGB file to run (ie: PhotoKit). Unless you know the dot gain of your printer gamma 2.2 is recommended. Should you choose to use an RGB working space, it doesn't really matter as long as it has a gamma of 2.2.
This approach works well when your image is destined for web or printing to inkjet, although some still prefer to print using RGB.
I see Bob already beat me to it....

David Good
Good Photoworks

[neil snape]

For scanner software that allows selecting the channel which to scan , then there is an advantage of saving out in greyscale over the same conversion in Photoshop. Why?
All scanners have a higher depth capture that is sometimes oversampling if you like, discarding some redundant signal noise or other.
Yet why bother if the options are not there and you're happy with the output to greyscale. I do feel you can better blend in Photoshop CS3 than the scanner will do, and in the case of the HP Z printers rgb printing of monotone is better than printing from the greyscale version of the same image.
Size wise, nothing will beat a compressed greyscale though, so my old scans are often scanned at very high res but saved as greyscale LZW tiff.