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Scanner Image RGB to Greyscale quality


C

cjogo

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If you scan a 6X7 B&W image RGB @ 3200 DPI outputing to 300 DPI (the Max of a Minolta Pro) and convert that file to greyscale..... will the print be a noticable 2/3 less quality ?


C Jo Go

http://fp2k.redshift.com/cjogo/c__joseph_gough.htm (large site, be patient)
 
Hi CJ :)

I don't know much about scanning, but here is a great article on the subject:

Scanning Tips: Wayne Fulton's site offers scanning tips and hints, fundamentals and other basic scanning information to help you get the most from your scanner.
 
scan formula

Quality factor (1.5 - 2.0) x Output dpi X magnification = input ppi

so if u want magazine quality for example..


1.5 (b&w) x 300 dpi x 1 = 450 ppi scan.

then set colour settings to...

Ink Colours: SWOP (coated)

Dot Gain: 20%

Seperation: UCR

Black Ink Limit: 60%

Total Ink Limit: 360%


then set highlights and shadows

to do this, create an adjustment layer (curves) from the bottom of the layers palette. dbble click both the highlight and shadow droppers and enter the following for each.....

Shadow (dark point) C - 95, M - 88, Y - 92, K - 60

Highlights (white point) C - 5, M - 3, Y - 4, K - 3

then with black point dropper, click on images darkest point, and with white point dropper click on images whitest point.

Then click ok and when offered to save settings as default click yes.

Change to greyscale very last, if at all.

What this does is set the halftones for your document and will also give you a more reliable idea of what it will look like printed.

Your quality will only decrease as far as your output is concerned and wont be noticable to anyone but you hehe.
 
No it won't, but you will never obtain the crispness of a black and white film.

What you do is put the R,G and B values to a mean value, making them the same. This can be done with the Channel Mixer, so you can influence the balance of the three channels. If you then change to greyscale mode, you have best result.

If you want the perfect greyscale of your pic, change to LAB mode and take the Luminosity/lightness channel. Evt you can set this to Greyscale too, question of filesize.

To enhance quality, you can change to nduotone mode and take a grey as second colour.

Missed your photographs. ;)
 
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