Re: [CAD_CAM_EDM_DRO] Re: CHEAP digital camera???

Alan Marconett KM6VV wrote:

> Hi Jon,
>
> Yeah, I meant 60 x 60 MM. Also called 2 1/4 x 2 1/4. Although I was
> once considering view cameras, nothing THAT big!
>
> I just had a thought, could an enlarger "project" an image of a slide or
> negative onto a scanner? Might need to disable internal lamp? That
> might give me a full scan.

No, in general, it won't work. The scanner expects a real image at the
surface of the plate you put the paper on. If the enlarger was projecting
an image on that plane, I guess that would constitute a real image, but
it would have the wrong collimation, and the scanner would lose about
90% of the light. Have you seen how bright the scanning lights are?
They are hard to look into, at least mine is painfully bright. So, I don't
think it would work, unless you have a 1000 W Xenon lamp in your
enlarger. OK, now I know why it won't work. The scanner has a really
tiny lens just in front of the line-scan CCD, and a moving mirror that
brings a slice of the page into view. The enlarger projects a virtual
image, not a real image, and most of it will not hit that lens at all.
You could rear-project onto a frosted film with mediocre results,
or redo the entire optics to eliminate the virtual image.

There might be a way to modify a page scanner to make it work.
You could rip out the scanning drive, and attach it to the film holder
in the enlarger, so it makes a proportionally smaller movement of the
35 mm slide. Using some non-spherical optics, set up the enlarger to
condense the light onto a narrow line on the slide, projecting about a 1/16"
wide strip of the slide onto a small area, through a much shorter FL
lens than you would normally use. Then, the line-scan CCD is placed
at the right position to recieve the real image. The tricky stuff is that
you would be projecting a 30 mm image strip onto a 20 mm line-scan
CCD. That could take some REALLY short FL lenses, or several
lenses. Actually, 2 20 - 40 mm lenses back-to-back might work out
pretty well.

Anyway, you can't just put the scanner on the table under the enlarger
and scan it, unfortunately!

Jon