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View Full Version : Can an Enlarger and Flatbed Scanner be Used Together?



Michael Heald
17-Sep-2006, 05:03
Hello! This may be a silly question, but I was wondering if an enlarger and flatbed scanner could be used together?

I read a few DIY articles about folks cobbling together an old scanner and a lens to back a scanning camera.

Can the same thing be done with an enlarger? Can I take a 4x5 negative and project it onto a flatbed scanner and obtain an image? The scanner would be placed where the paper would be. The projected film plane on the scanner could be adjusted with the enlarger controls to find the best focus.

I'm not sure how the enlarger optics and the scanner optics would work together. I'm not that much of a tinkerer that I would want to try and remove the scanner's optics in order to use the enlarger optics.

Anyway, just a thought. If a scanner and enlarger could work together, it would seem that scanned image quality could be improved by a factor of 2 (? slightly less, since I'm sure any enlarger would have imperfections?) if a 4x5 were projected onto a scanner and then captured as an 8x10. Best regards.

Mike

Donald Qualls
17-Sep-2006, 14:36
The simple scanner cameras I've seen suggest that if you're willing to put some effort into it, it can be made to work well enough. I'm not sure it would be either less effort or a better result than making your best contact print and scanning that, however; my flatbed (eight or so years old, though it was a top-end professional model when new) will pull 2400 ppi from a print, or from sheet film up to 8x10. Getting four times the file size (since both dimensions would double) seems like a minimal improvement over that, given that's equivalent to a 12x enlargement with 200 ppi final resolution -- which would produce approximately a 48x60 inch print. Throw in the potential image quality degradation from the combination of optics, and I wonder if you'd gain anything over scanning a "best" quality contact print...

Bruce Watson
17-Sep-2006, 15:40
Can I take a 4x5 negative and project it onto a flatbed scanner and obtain an image? The scanner would be placed where the paper would be.

Yes you can. I'm not sure why you would, but you can surely do it.


I'm not sure how the enlarger optics and the scanner optics would work together.

I'm not either, but I can't image that adding another set of optics (and their losses) to the equation will improve anything. In addition, you'll have issues aligning the enlarger accurately with the scanner. You'll also have issues with the directionality of the light from the enlarger. The conical light from the enlarger will hit the edge of the sensor array at an angle while the sensor array expects light to be perpendicular to the sensor all the way across. And, of course, the sensor array is expecting light in a certain range of levels. If you don't give it enough light in the dense areas you'll get either no signal or lots of noise. Too much will blow out your low density areas to pure white.


If a scanner and enlarger could work together, it would seem that scanned image quality could be improved by a factor of 2 (? slightly less, since I'm sure any enlarger would have imperfections?) if a 4x5 were projected onto a scanner and then captured as an 8x10.

I'm not sure I understand your logic here. Why do you think you'll get an improvement in image quality doing this?

While theory is interesting, you can easily run some tests to prove your theory out. Scan the film normally first and make a print from that file. They scan it using the enlarger as a light source and make a print from this new file. Compare under the same lighting. Tell us what you think.

Emmanuel BIGLER
18-Sep-2006, 02:47
I fully agree with Bruce. There is a difficult problem to properly have light rays generated by the enlarger to actually enter the moving scanning lens. In a flatbed scanner the light path for illumination is totally different from what would fall from the enlarging lens. It is a bit difficult to explain the problem with words, but a friend of mine tried and got nothing usable for this reason.To me this problem is related to the general question of conjugating pupils in a compound optical system, a more serious problem to solve IMHO than the predictable and, of course, very damageable loss of image quality induced by stacking two lenses one after another. Another problem is adjusting the proper level of light intensity at the source but this could be worked out by trial and error.
But it is worth giving it a try just to understand where the illumination problem is.

Michael Heald
18-Sep-2006, 03:45
Hello! Thank you for the guidance. Best regards.

Mike

paulr
18-Sep-2006, 05:01
It sounds fun, but also a bit like a solution in search of a problem.

One of the things I like most about scanning is freedom from enlarger illumination falloff. Scanned images are perfectly even from corner to corner. You'd be kissing that advantage goodbye. And as others said, the introduction of another set of optics will likely make things worse.

It might be suited for experimental work ... like the combination photogram/projections that Anne Arden McDonald does in her botanicals series (she just used an enlarger and photo paper, but with the contraption you describe, you'll probably find other ideas).

MJSfoto1956
18-Sep-2006, 05:06
This was attempted back in the early 1990's and it "does" work.. but...

- You'll need a powerful light in the enlarger, and
- You may need a fresnel lens on the flatbed to get the light rays to be parallel with the scanner's optics.

Technically doable, but not necessarily practical. OTOH, I have successfully hooked up a Beseler 45mx enlarger to a spare Linhof 4x5 camera used together with a BetterLight scan back and the results are phenomenal -- it is my primary film scanner now.

Don Bryant
18-Sep-2006, 07:13
Hello! This may be a silly question, but I was wondering if an enlarger and flatbed scanner could be used together?

I read a few DIY articles about folks cobbling together an old scanner and a lens to back a scanning camera.

Can the same thing be done with an enlarger? Can I take a 4x5 negative and project it onto a flatbed scanner and obtain an image? The scanner would be placed where the paper would be. The projected film plane on the scanner could be adjusted with the enlarger controls to find the best focus.

I'm not sure how the enlarger optics and the scanner optics would work together. I'm not that much of a tinkerer that I would want to try and remove the scanner's optics in order to use the enlarger optics.

Anyway, just a thought. If a scanner and enlarger could work together, it would seem that scanned image quality could be improved by a factor of 2 (? slightly less, since I'm sure any enlarger would have imperfections?) if a 4x5 were projected onto a scanner and then captured as an 8x10. Best regards.

Mike
A projected image onto the platen of a flat bed scanner will not work.

Don Bryant

Emmanuel BIGLER
20-Sep-2006, 03:53
You may need a fresnel lens
Yes, you may also consider that the Fresnel lens could, ideally, conjugate the image of the enlarger lens pupil to the scannning lens entrance pupil. I doubt that this can be achieved with precision but at least it could help to bend the light rays toward the scanning lens.
The problem is exactly similar to the use of a Fresnel lens combined to a ground glass in a view camera, the goal is to bend as much rays as possible toward the photographer's eyes.
Since the photographer want to move his eye across the whole ground glass (GG), what you can do is simply put the focal point of the Fresnel around the exit pupil of the taking lens, so that the exit puil appears to be very big and very far away through the Fresnel. When you move your eye across the GG, you always see a part of the pupil in the background sending light to the ground glass.
Probably the same idea that could work for a scanner illuminated by an enlarger. Of course you should not place the Fresnel lens too close to the flatbed glass, since you don not want to scan the circles together with the image. Those circles should be blurred by placing them at some distance of the image to be scanned, but in any case the Fresnel lens would be somewhere in the light path...