Photocopying old browned paper schematics etc

One way would be, to scan them into your PC and apply some kind of color filtering. May take some effort to get the right filter settings, but in the end you get 'as new' printouts :-)

Hi...

Please do yourself a favour and don't even think about cleaning mirrors and lenses...

You haven't mentioned the scanner maker or model, but I suspect what you're looking to do is scan them in either your choice of either black and white or grayscale. Suspicion is that you'll find grayscale more to your liking, but experiment yourself to decide.

You mention wanting to bring the exposure level up; not exactly sure what it is you mean, but what you really want to "play around with" is the gamma.

Here's how I'd do it: Find the whitest white (note that white *doesn't* mean white, but rather an absense of colour. Set that to 100% Next find the blackest black (again, not black but dark with an absense of colour). Set that to 0%. Next move the gamma to your eyes pleasure, making the mid-tone grays look good.

Take care.

Ken

Let me tell you photographer's trick in handling discolored prints (which is akin to your problem) and that is rephotographing with a brown or yellow filter over the lens.(and shooting in B&W) In your case, you won't reshoot the image, but by resetting the luminance point to nuetral, in this case some shade of brown, you effectively have redefined the image as brown and white. If you consider the brown as white, the black falls into place. I would experiment by playing with a software filter to compensate for brown either subtractively or additively, or try adjusting same for the complimentary color. I'm assuming you have software capable of this either as your scanner package, or perhaps some version of Photoshop.

Hello, les! You wrote on Tue, 21 Mar 2006 16:23:25 -0600:

I think the OP was talking about a common or garden laser photocopier probably A3, with a machine like that, your options are very limited and I would recommend trying the last posters idea with a camera with a decent mp count and filters, the scanner has potential, but an A4 scanner would make it very hard work stitching the parts together. Of course it depends on the physical size of the schematics but with a camera, that's not as much of an issue. either way, to get decent results is going to take some effort. Still, I'm sure that when you have recovered the schematics in some decent electronic form you will make them available to all your friends here on sci.electronics.repair, - wont you? :^) Pete

lWith best regards, 3T39. E-mail: snipped-for-privacy@hotmail.com