Making a scanner with a DSLR

[Ben Syverson]

The macro copy stand would need to beat the epson by a fair bit, say 3 times better or 7200 dpi.
That is better than 50 megapix per sqaure inch.
So you need more than four but not as many as 9 non overlapping images in the inch to better that resolution. What is the most affordable solution to get a shot of a third of an inch square area?

50 MP per square inch is in the overkill category, unless you're talking about fine grained B&W shot on Leica or Zeiss.

With that said, most of the superzooms / high-end compacts have relatively small sensors with great macro lenses. Find one that can go to 1:1 or beyond, and you could probably produce a gigapixel image of 6x6. Whether or not it's rational is another question...

The nice thing about APS-C or FF DSLRs is that they cover a lot of area with fantastic quality, so you can cover the negative with fewer exposures.

[tlitody]

but if you're fairly close, and using a wide field of view, the distortion gets really nasty, and since the stretching is so extreme, the end resolution gets really low on the edges.

get a Leica M9 with a Zeiss zm 2/35. There is no distortion.

[Frank Petronio]

OK rent or buy a better scanning back for your 4x5 camera. Mount your best 4x5 enlarging lens on your 4x5 and photograph you negs from a very bright light table in one go. I think the graphics repro industry have been doing this for some while. Art work is digitised in this way. I just think that we are trying to reinvent the wheel here.

or

ICG still make drum scanners last time I looked. So they are not cheap. So instead of investing your $1,000,000 dollars in R&D, why not just pool enough to buy a highend drum scanner, employ someone to do scanning and offer the service country wide and those that contributed to the scanner get cheap scans done. Problem solved.

The point is that that there are trillions of film images still out there, I have a billion or so on my office bookshelves. I don't think any scanners are being made beyond Epsons and a few inexpensive slide scanners, so they are only a product cycle or two from being phased out. In a few years, spare parts my dry up. So the idea is how might we scan all this existing film, not to mention any new materials, 10-20 years down the road?

But yes, if I want a quality drum scan tomorrow then I'd just send out to Lenny or some other good provider. But what happens when Lenny gets old and his machines aren't repairable any more?

A digital photography rig as is being discussed makes a lot of sense because it is relatively "future-proof" and can be upgraded indefinitely.

[Ben Syverson]

get a Leica M9 with a Zeiss zm 2/35. There is no distortion.

Overkill... all macro lenses are designed to have virtually 0 distortion at working distance.

[sethlatimer]

It sounds like the recommendation is to attach a lens on a macro bellows? to a live view DSLR? Is there a particular lens or type of lens that would work best? 50mm 2.8 enlarger lens?

On another topic, I have been working a bit with the imagemagick and panotools software. These are open source tools that enable batch processing and scripting of files.
I know there is some software that can control the camera but I am not that familiar with that. The camera control software needs to be linked to the moving table(prolly arduino). That linking is beyond my ability.

I could definitely work on the stiching and exposure balancing with the imagemagick and panotools, and maybe a little gui with other open source tools.
Seth

[Peter De Smidt]

...OK rent or buy a better scanning back for your 4x5 camera. ...

....ICG still make drum scanners last time I looked....

...So instead of investing your $1,000,000 dollars in R&D….

...get a Leica M9 with a Zeiss zm 2/35. There is no distortion....

If I had $1,000,000, I'd buy a premier or two. Scratch that. I'd just have Lenny scan my negatives. But I don't. Nor do I have the change for any of the other suggestions. You seemed to have missed the "inexpensive" criteria that all of us are including.

You don't like the idea. That's fine. There's no reason that you have to take part.

[Peter De Smidt]

It sounds like the recommendation is to attach a lens on a macro bellows? to a live view DSLR? Is there a particular lens or type of lens that would work best? 50mm 2.8 enlarger lens?

That would allow very high resolution, but we don't know yet if it's overkill. It does add difficulty in sourcing and cost, mainly for the bellows.

Most Macro lenses go to 1:1, and extension tubes can help them get much closer.

I could definitely work on the stiching and exposure balancing with the imagemagick and panotools, and maybe a little gui with other open source tools.
Seth

That's good to know.

[Ben Syverson]

FWIW, you may have trouble with extension tube stability, and I would be very hesitant to push a macro lens beyond its engineered range. You may get okay performance, but a 1:1 macro lens has been laid out by the optical engineer for lowest distortion and optimal performance at exactly 1:1.

At the very least, testing is warranted. But honestly, I don't see the rationale for pushing past 1:1. With pixel densities as they are, you're getting 4000 samples / inch or better.

[Kirk Gittings]

To me the issue would be the software because present day stitching software IME does not do well with detail poor areas like skies. If you broke down a 4x5 into say 16 tiles and the top half were of an overcast sky you would have a difficult task of alignment at hand.

[Peter De Smidt]

Kirk's worry is, imo, the most serious one facing the idea.

I'll try taking some test shots tonight.