Scanning B&W film???

[Harley Goldman]

I shot some Acros last weekend. I am using the 4990 and Silverfast Ai. I can scan it as a negative, 16 bit grayscale (and since there are no Fuji B&W film choices in the popup box, I selected Koday TMax). Then I scan. I assume this is the correct procedure to scan as a BW neg? If not, what should I do different?


I have been reading about people scanning B&W negs using only one color channel, red, blue or green. One is generally sharper than the others. I have no idea how to go about doing that. Set it up as a positive, not a negative, then convert it in PS? If it is a positive, how do I go about selecting a color channel to use? What control(s) in Silverfast should I use? No clue. Then once it scanned, use channel mixer to convert it to B&W? I normally use chrome for B&W and have used the channel mixer for my conversions, but this B&W stuff has me stumped.

Any tips would be greatly appreciated.

[Michael Mutmansky]

Harley,

To scan and drop out two channels, I recommend scanning as a color negative with 16 bit color depth.

You will get a very large file, but then when you load it in PS, you can use the channel mixer to eliminate the two channels that you don't want, and then convert to greyscale to complete the removal of the channels. The file will then be 1/3 the size of the color file.

In the Channel Mixer, set the value of the channel you want to keep to 100%, and the other two to 0%, and check the Grayscale box at the bottom. That effectively copies 100% or the selected channel and 0% of the other two to each of the three channels.

Then got to Image:Mode:Grayscale to get it to be a single channel image.

There are other ways to do this channel reduction, but I find this way to be the easiest to describe to people.

I have yet to see an Epson scanner that is not sharpest in the Green channel, but there may be some that are better in another channel. If you aren't going to test, choose the Green channel.

---Michael

[Walter Calahan]

I second Michael. I always scan B&W as a color negative, and then do my adjustments in PS.

[Kirk Gittings]

I have yet to see an Epson scanner that is not sharpest in the Green channel, but there may be some that are better in another channel. If you aren't going to test, choose the Green channel.

Very true. I find it easiest to just go over to the channel palette, duplicate the green channel and then delete all the rest. It seems simplest to me.

[Michael Mutmansky]

Kirk,

That's one of the other ways, but that can cause confusion with some people because as soon as you delete one channel, the other two go to CMYK channel designations, and that seems to confuse people...

Regardless, it is easy to set up an action to do either of these procedures with the click of a button, so it's easy with any method.


---Michael

[Harley Goldman]

When I scan as a color negative, Silverfast has a pop-up box asking to select the film type. Does it matter which one I choose?

[Ron Marshall]

I always scan b/w negs in 16 bit color. The red channel image is signifigantly less sharp than either the blue or green, and on my 4990 the green has a very slight edge. I wrote a macro that extracts the green channel, then I delete the others.

[Michael Mutmansky]

Harley,

Not really, just make it look good, and you'll be OK for starters.

Actually, the best thing to do would be to develop a curve for your film, so that you are getting consistent results all the time. You don't need to do that for a quick one-off, though.

All of those adjustments can be done in PS anyway, so it is not terribly important that the scan look perfectly distributed in SF. Just make sure the endpoints are properly taken care of, and you should be OK.


---Michael

[Ed Richards]

Another alternative is to use Vuescan, which will let you scan from just one channel. I also go for green, although I use a Canon 9950. This has a big advantage if you want to scan at full res (4800) and downsample for noise reduction. A single channel scan at 4800 for 4x5 is 770 megs. Do that in color and you will probably choke your system with the 2 gig+ file.