Re: Most Compelling B&W Scans on 4990 w/48 bit Scan and PS Conversion?
Quote:
Originally Posted by
Ken Lee
I just scan in regular b&w mode at 16-bits. I couldn't find a substantial difference with the various RGB channels, to justify the additional time and effort.
A high-end scanner would do better, but the results I get, seem more than
adequate.
I agree with others in that the Green channel will give the finest grain with the Epson 4990. but the difference compared to using all three channels is not great. If the issue is scanning LF B&W film in 4X5 or 5X7 size with an Epson 4990 I basically agree with Ken in that the small decrease in grain size one can get by scanning in RGB and using the Greeen channel does not justify the considerable additional scan time and file size compared to scanning in B&W 16 bit, at least not for normal size prints.
For MF negatives that will require a lot more magnification my experience is that there is a clear advantage to an RGB scan, and then selecting the best channel, which is usually Green.
Sandy King
Re: Most Compelling B&W Scans on 4990 w/48 bit Scan and PS Conversion?
Agreed-if there's a way to scan the green channel independently in Silverfast, it's not obvious. I suspect this approach may be similar to a 16bit grayscale output implementation anyway?
However, one can manipulate the green channel characteristics in Silverfast at prescan. I'm going to try it vs. doing it in PS.
Has anyone else ever tried the green channel adjustment (histogram/curves) in Silverfast during the prescan/scan process as a alternative to PS workflow?
Re: Most Compelling B&W Scans on 4990 w/48 bit Scan and PS Conversion?
No, but I would be interested in your results.
Re: Most Compelling B&W Scans on 4990 w/48 bit Scan and PS Conversion?
Quote:
Originally Posted by
DigitalDude
Agreed-if there's a way to scan the green channel independently in Silverfast, it's not obvious...
General/ Options/ Special/ Color Filter/ select green if that is your preference.
Tyler
Re: Most Compelling B&W Scans on 4990 w/48 bit Scan and PS Conversion?
Quote:
Originally Posted by
Tyler Boley
General/ Options/ Special/ Color Filter/ select green if that is your preference.
Tyler
Perhaps I am misunderstanding this thread, but so far as I understand there is no way to scan only in Green channel with a modern tri-linear CCD. When you scan you get all three of the RGB channels, and then in post-scan processing you can drop one or more of the channels.
I have an older Leafscan 45 which when used in RGB does three separate scans with RGB filters, or one with a neutral density filter. This scanner does permit a scan with either R, G or B, or with ND.
Sandy King
Re: Most Compelling B&W Scans on 4990 w/48 bit Scan and PS Conversion?
Sorry Sandy, I just saw that post and thought someone just needed to know where the control was in the software. It works on my Howtek, perhaps the options aren't there when installed for a ccd scanner...
Tyler
Re: Most Compelling B&W Scans on 4990 w/48 bit Scan and PS Conversion?
Quote:
Originally Posted by
Tyler Boley
General/ Options/ Special/ Color Filter/ select green if that is your preference.
Tyler
I'm not all all sure that this proceedure is the same thing as selecting the green channel and I don't have time to test it. I would think it would nbe named something to that effect rather than a "color filter", but then a again this is SF and names can be a little obtuse. Unfortunately I have lent my SF manual to someone and will not see it for awhile.
Re: Most Compelling B&W Scans on 4990 w/48 bit Scan and PS Conversion?
Quote:
Originally Posted by
Kirk Gittings
I'm not all all sure that this proceedure is the same thing as selecting the green channel...
it is, I've tested it extensively.
Tyler
Re: Most Compelling B&W Scans on 4990 w/48 bit Scan and PS Conversion?
BINGO, You are absolutely right!!!! Great piece of info.
Quote:
Martin from SF in the SF forum......
1. The color use select in "color filter" is not the color that is ignored, but the color that is selected for gray scaning. If you choose red, the red channel is selected, green selects green and blue selects blue. If you choose white, a neutral gray (combination of RGB) is selected. I talk to our documentation team about the typo in the manual.
Re: Most Compelling B&W Scans on 4990 w/48 bit Scan and PS Conversion?
Well, for cumbersome methodology I think I have you all beat, however I think this gives me a good starting point. I use CS2, and scan with the EPSON software.
1. Scan the b/w neg as a color positive. Yes, a color positive. Don't hit the auto-adjust button -- just pull it in as is.
2. Remove all but the green channel.
3. Make a curves layer.
4. Use the curves layer to invert the positive.
5. Make another curves layer between the original (2) and the inverter (4).
6. In the sandwich'd curves layer (5), set the show clipping checkbox. Now, using the little arrow thingies just below the curve box, pull the left one to the right, and the right one to the left. You'll know you'll have gone too far because the 'show clipping' feature will show you so. Unclick "show clipping" when there's no more speckles.
7. Flatten the image (chuck away all the layers).
8. Convert to greyscale.
All this can be squashed into two actions 1) initial uptake and range setting 2) flatten and convert to grey.
Now, this does NOT produce a perfect well balanced result -- it's not supposed to -- but it does present you with all the raw information that the negative will ever give you without block-outs or burn-outs introduced by the scanning software. If there are any burned out spots at this point, it's your negative, not the scan. Likewise for block-outs.
Like I said at the top -- I think it's the best negative import method I've found so far.
gb
