B&W photocopy from Colour Problem

In article <c95b6s$hi2$ says…

I forgot to mention I am using Photoshop 5.5

Kia Ora
Our Church has an Analogue photo copier for it’s newsletters etc. I have tried converting my colour digital photos to B&W using Grayscale,

Colour

Channels, Channel Mixers & other experiments, but the result is always totally unacceptable when photocopied, usually too dark even when lightened as much as possible.
On the other hand, some seemingly random colour photos straight copied come

out

reasonably well.
Is there a hue or contrast or other factor I might use to trick the

photocopier

to produce an acceptable result? I am not expecting magic! Thanks
Mac

"Mac Lynch" wrote in message

Kia Ora
Our Church has an Analogue photo copier for it’s newsletters etc. I have tried converting my colour digital photos to B&W using Grayscale,

Colour

Channels, Channel Mixers & other experiments, but the result is always

totally

unacceptable when photocopied, usually too dark even when lightened as

much as

possible.

Have you tried blessing the damn machine?

On the other hand, some seemingly random colour photos straight copied

come out

reasonably well.
Is there a hue or contrast or other factor I might use to trick the

photocopier

to produce an acceptable result?

Impossible to tell, you’ll just have to try.

I am not expecting magic!

Yes you are, otherwise you would not go to church…

Mac Lynch wrote:

Kia Ora
Our Church has an Analogue photo copier for it’s newsletters etc. I have tried converting my colour digital photos to B&W using Grayscale, Colour Channels, Channel Mixers & other experiments, but the result is always totally unacceptable when photocopied, usually too dark even when lightened as much as possible.
On the other hand, some seemingly random colour photos straight copied come out reasonably well.
Is there a hue or contrast or other factor I might use to trick the photocopier to produce an acceptable result? I am not expecting magic!
Thanks
Mac

Mac,

This may be solved by treating it as a grayscale issue.

I would start by creating a gray step wedge (lay down a gradient, then posterize it to 16 levels) and printing it on an inkjet printer for reference. Make sure the image is grayscale. Remember for inks, darkness is from 0 percent (white) to 100 percent (black).

Then see where pure black and 50% gray wind up. For example, suppose 75% gray prints as pure black, and 20% gray looks like a 50% gray.

Click the transfer button in Photoshop’s Page Setup… to access the the printer transfer curves, which is a little involved, but once you’ve done it you will get something that is very close to what you see on the screen. All you need to do is set the percentages you estimated by – for the example numbers above, put an entry of 50 in the 20% box, and 100 in the 75% box.

Print out another step wedge, make sure it is substantially lighter than before, and see how close the copied image is to your original inkjet printout.

If you prefer not to use the printer transfer curves, another choice would be to create a set of curves, identical to the transfer curves, that you run your image through before printing.

Also, get the model number of your photocopier, and post your question to comp.publish.prepress. There are experienced press folks there who may be able to help you with more specific information relating to your equipment – for example there may be a way to adjust the darkness of the copier. —

Mike Russell
www.curvemeister.com
www.geigy.2y.net

I left out a step.

I would start by creating a gray step wedge (lay down a gradient, then posterize it to 16 levels) and printing it on an inkjet printer for reference. Make sure the image is grayscale. Remember for inks, darkness is from 0 percent (white) to 100 percent (black).

Missing step –> Now make your copy, and compare it to the image from your inkjet. If you do not have an inkjet or other printer available, compare the copy with the screen image of the gradient. Don’t overdo the precision – just pay attention to middle gray and pure black.

Then see where pure black and 50% gray wind up. For example, suppose 75% gray prints as pure black, and 20% gray looks like a 50% gray.
Click the transfer button in Photoshop’s Page Setup… to access the the printer transfer curves, which is a little involved, but once you’ve done it you will get something that is very close to what you see on the screen. All you need to do is set the percentages you estimated by – for the example numbers above, put an entry of 50 in the 20% box, and 100 in the 75% box.

Print out another step wedge, make sure it is substantially lighter than before, and see how close the copied image is to your original inkjet printout.

If you prefer not to use the printer transfer curves, another choice would be to create a set of curves, identical to the transfer curves, that you run your image through before printing.

Also, get the model number of your photocopier, and post your question to comp.publish.prepress. There are experienced press folks there who may be able to help you with more specific information relating to your equipment – for example there may be a way to adjust the darkness of the copier.

—

Mike Russell
www.curvemeister.com
www.geigy.2y.net

In article <Z5Uuc.76983$>,
says…

Thanks for the wonderful response I have got to my project. I am trying several answers & think I am making real progress.
Your time & help is appreciated.
Mac

In article <c9ihnb$3nm$ says…

In article <Z5Uuc.76983$>,
says…

Thanks for the wonderful response I have got to my project. I am trying

several

answers & think I am making real progress.
Your time & help is appreciated.
Mac

BTW
If anybody else is trying Mike’s suggestions,the transfer button he refers to is in Photoshop’s Print with Preview, not Page setup. With my version 7 of Photoshop anyway!
Mac