DSLR Scanner: Scans and Comparisons

[Peter J. De Smidt]

The head of our European research branch has requested a thread to post scans concerning dslr scanning, which includes comparisons to other methods, and so here it is.

[cabbiinc]

When I considered scanning film with a camera a few thoughts came to mind.

a) When scanning with a dSLR vs a dedicated scanner you have to take into account lens distortions. That isn't to say that a scanner doesn't have lens distortions as well, but it's a much more controlled environment. This is something that can be corrected for, but would be one more step that may be missed or more likely done improperly.
b) Size limitation. Most dSLRs are under 20mp. But I can scan 4x5 film at far more pixels than the current crop of typical dSLRs can afford.
c) Dust removal. Even with diligent dust control measures you'll still find dust. Having a dedicated scanner with proper dust removal is, in my opinion, worth the extra cost and time it takes to scan.
d) Size. Even a medium or large sized scanner will likely take up less room than a copy stand type setup realistically.

On the other hand...
1) Time. It takes much longer to use a flatbed or dedicated film scanner to scan even 35mm film than it would to just *click*. Is time worth more than the reasons stated above?

These are just my opinions. Sorry, I don't have any examples of one vs the other.

[Peter J. De Smidt]

This is not the proper thread for this sort of discussion.

[Old-N-Feeble]

Huh?

[Peter J. De Smidt]

This thread is for showing scans.
Such as:
http://i955.photobucket.com/albums/ae37/peterdesmidt/Lighthouse_Cezanne.jpg

Versus this:

http://i955.photobucket.com/albums/ae37/peterdesmidt/LightHousePTGui.jpg

The first image is from a Cezanne scan. The second is from my dslr scanner.

The original thread is the place for general discussion of the project. It is: http://www.largeformatphotography.info/forum/showthread.php?84769-Making-a-scanner-with-a-DSLR

[Peter York]

Peter, what were the scan settings for the Cezanne? The DSLR scan is excellent. Looks very promising!

[Peter J. De Smidt]

Hi Peter,

4000 spi.

To me, it looks like the AN holder held the Cezanne back.

[Peter York]

I think you are right. To my eye its most apparent in the rounded bits, but it shows everywhere (ugh, back to testing). I wonder if the differences are visible in print (and at what size).

A DSLR scanner that reaches 4000 spi would be fantastic. Have you "scanned" an entire 4x5? I'm wondering what the time investment per image is.

[Peter J. De Smidt]

I used the Cezanne clam shell holder for the dslr at first. A close-up view of the grain showed smearing, and so I ditched the holder and taped the negative emulsion up to the thick glass plate. That's what gave the scan above. The Cezanne scan shows the same smearing. Soon I'll scan a negative on the Cezanne without going through a sheet of AN acrylic. It should perform better.

Note that these prints would be huge, on the order of 50" prints from a 6x7 negative. With a computer and the ease of looking at a 100% pixel view, it's so easy to become obsessed about very minor things.

I haven't scanned an entire 4x5. So far I"ve stuck to 6x7cm negatives, just to make things easier. Joseph did a 4x5" negative, if I remember rightly. Right now I'm concentrating on automation. The team made some good progress today. We've narrowed down stepper motors, drivers and software candidates.

[Kirk Gittings]

I sure appreciate your efforts Peter.

[sully75]

yeah me too. Not sure how much energy I would put into fiddling with building one, but if it were something that were a sure thing, more or less, I'd be all over it.

[Peter J. De Smidt]

Thanks Kirk!

Sully, the goal is to come up with a fairly easy to replicate system. In particular, I'm trying to stay away from a design that requires expensive tools. For instance, to make my current prototype, you'd need a decent and well-aligned table saw, but it'd be fairly easy to make something similar out of alternate materials, such as threaded steel pipe, with only wrenches and a drill, at least you could for the camera support stage. Once we get a fully working prototype we can do some sample scans for people. That way you should be able to see exactly what is involved and what the results are. It certainly won't be for everyone.

[jb7]

They look very clean Peter, and remarkably grain free-

These are filthy by comparison, but they're tests of the process, and not to be seen as final output-
from the DSLR Scanner No.7 thread-

Details are screenshots from V750 4000dpi scans overlaid on the DSLR Stitched output, about 600kb each-
I re-stitchsd the original; I found a few anomalies, on closer inspection-


71015


http://img209.imageshack.us/img209/1681/v750jb7dslrcomparison1.jpg

http://img220.imageshack.us/img220/8463/v750jb7dslrcomparison2.jpg

http://img717.imageshack.us/img717/5971/v750jb7dslrcomparison3.jpg

http://img714.imageshack.us/img714/1904/v750jb7dslrcomparison4.jpg

[Peter J. De Smidt]

That's a very nice comparison, Joseph.

[cabbiinc]

This is not the proper thread for this sort of discussion.
Sorry, I didn't see the other thread and you hadn't received a reply in a few days. Thought I'd make a comment.

[Adrian Pybus]

These comparisons look really promising.