Old Stuff Perhaps

[Mervyn Long]

Forgive me if this has been covered in past discussions.

Sanning pics into the computer: is it better, when scanning a dark image, to lighten during the scanning process, or to lighten the scanned image, in order to minimise 'grain" - or doesn't it make any difference?

Mervyn

[ktinkel]

Forgive me if this has been covered in past discussions.

Sanning pics into the computer: is it better, when scanning a dark image, to lighten during the scanning process, or to lighten the scanned image, in order to minimise 'grain" - or doesn't it make any difference?I think you have more control in Photoshop or other high-end image editor than in most scanner software.

At the very least you can set everything, point by point (assuming you know what you are doing) — most scanning software is a bit of a black box.

I generally leave it all to the experts, so scan for optimum detail, then hand the file over for color-correction and the like.

[terrie]

>>Mervyn: Sanning pics into the computer: is it better, when scanning a dark image, to lighten during the scanning process, or to lighten the scanned image, in order to minimise 'grain" - or doesn't it make any difference?


There are many people who do this work using the scanning software--particularly if they are using something like Silverfast which is pretty sophisticated (should be for what it costs...'-}})--but if you have Photoshop (or other imaging software), I'd just do the basic scan and do anything else in Photoshop--that's what I do both because I have more control in Photoshop but also I can see the image better in Photoshop...

Terrie

[Cristen Gillespie]

Well, having just been told to do all the work in Photoshop<G>, I'm going to say that if an image is dark, I want to be sure I catch detail that is there. I don't do a lot of correcting in Silverfast -- some, but mainly I prefer a "flat" scan to work with. That is, I scan in 16 bits, and try to ensure that I have all the data I can get at both ends. That *can* mean lightening, or darkening, the scan in the scanning software. Otherwise, what gets scanned is too dark, or too blown out, for retrieving data in Photoshop.

[Mervyn Long]

Hi Cristen -

That was what my instinict told me ......

Mervyn

[Cristen Gillespie]

I'd say "good instincts" because they just happen to coincide with mine. LOL

[mact]

I would do "lightening" as follows for sheetfed (all in Pshop):

1) in RGB, set white point and black point (using curves) if you have them (some images do not). I usually use about 10 for the black point ansd 245 for the white. All channels the same (or nearly so).

2) If too dark, to LAB, channel 1 (lightness) lighten with curves.

3) back to RGB (there is no loss betrween LAB and RGB and back and forth). If image neutrals look neutral (neutral = r=g=b), you can move to cmyk.

4) set up cmyk conversion to Light black generation, max 75% black, 320 total ink, 17% dot gain.

5) review colors such as neutrals (should have a little more cyan than the m&y), skin tones, etc. Adjusting as required.

6) you done.

[mact]

16 bit really does not afford any demonstrably better final result than 8-bit, but it does make a much larger file.

Dan Margulis has an ongping quest for images that come out better when handled in 16 bit rather than 8 and thus far, if I read him correctly, has not seen such a case. Histogram data is virtually irrelevant in photos--photos naturally lack data in some areas and trying to push it in there might make a nicer histo, but images on paper at the delivery end of a press is the name of the game not histos.

[Franca]

Ooh, thanks, Mac!

[terrie]

>>mact: 3) back to RGB (there is no loss betrween LAB and RGB and back and forth). If image neutrals look neutral (neutral = r=g=b), you can move to cmyk.

What about if you had other corrections to make...say you needed to clean up dust or other artifacts (love the healing brush!)...would you stay in RGB to do that and then convert to cmyk???

Terrie

[mact]

If you have the usual crap to clean up such that the filter can do it, try LAB. Run the filter (at high level) on the a and b channels (the color channels) and see how that works. This often can help reduce the artifacts on the (blue/yellow) channel.

If I have the choice I'd rather do this sort of tweak on channels ratehr than overall. But sometimes you're handed Pineapple-Pepperoni Pizza when you're really, really hungry.

[marlene]

But sometimes you're handed Pineapple-Pepperoni Pizza when you're really, really hungry.

You can always pick off the pineapple. <g>

Gee, I haven't seen you in a while! How are you?

mxh

[terrie]

>>mact: If you have the usual crap to clean up such that the filter can do it, try LAB. Run the filter (at high level) on the a and b channels (the color channels) and see how that works. This often can help reduce the artifacts on the (blue/yellow) channel.

I meant "artifacts" in a kind of generalized way...things like dust, scratches, etc that need to be cleaned up...I can't see any reason to take it into LAB for stuff I'd use the healing brush on...

I was just curious if you did that sort of clean-up in RGB or after you cmyk'd it...

Terrie