All of the good stitching tools, including (free) PanoTools, deal with this transparently. They also have solvers that will undo any lens distortions as well, which is obviously important for the (cheap) wideangles commonly used for landscape stitching.Originally Posted by Mike Anderson
ex-Pic-A-Day (slowed after 2 years)
on flickr
Analogue Photo and Film FAQ (for APUG)
Open Source F/Stop Timer
Wow, 23 pages. I can't read it all but perhaps someone (Frank?) wants to summarize what is a very interesting topic.
We used to make camera-based scanners that created step and stitch images at any resolution you wish. These were mounted on microscopes and did a nice job, but we never claimed to have the DR of PMT-based scanners. Never happen except with hi-bit cryogenic cameras viewing self-luminous targets. Works OK (only OK for complex reasons) at about 4D of dynamic range under those conditions. No resemblance to a film scanner, though.
The core problem (not the only problem) is flare. As soon as you are dealing with a detector array and an illuminating beam, you have flare. That flare limits you to much less than 4D of DR, even at low precisions.
In contrast, a scanning PMT limits flare because the beam is tightly constrained (especially if it is a confocal scanner). That's why drums are better than any array-based scanners (including linear arrays), and why camera-based scanners cannot match the performance of scanning PMTs. You can be fairly clever in limiting the flare component in a linear array scanner, but that only goes so far.
Making a crappy scanning PMT device is easy. Making one with the tolerances to deliver both spatial and bit-depth precision is very demanding (= expensive). So, how many of us LFers would shell out for a new product? Aztec would know. The numbers are far too small.
Rick,
As much as I'd like to sell you my Olympus E-520* (with live view! can mount Nikon lenses!), you have the tethering software you need on the disk that came with the 5D. Here's what google told me:
http://www.ehow.com/how_7330275_can-...computer_.html So, it looks like you can park your laptop next to the setup and check focus instantly.
Will, who has no nifty tagline, or ready cash, Frostmill
*seriously, I'm going to put it up on the classifieds any day now.
Digital camera mated to a microscope. Multiple exposures and stitching.
The one in the link has a built in digicam, but at that price point probably not acceptable image quality.
http://www.microscope-depot.com/seriesU.asp
But if someone already has a decent DSLR then a microscope with a camera mount, stitching and perhaps HDR should be doable for not too much.
To be frank, I'm not Frank, but I'll give it a go anyway.
My goals are to make a scanner such that:
1. It's quality is significantly better than an Epson flatbed.
2. It's easy to use.
3. It's fairly easy to build from non-esoteric or extremely expensive parts.
4. It can be used in a manual mode.
5. It can be automated, at least to an extent.
6. It can be used quickly for proofing, or more slowly for higher quality.
7. Finally, a "how-to" manual will be made which would help interested parties build their own scanner.
Those are my goals, and other people's will probably differ, which is great. I'm a little tired, though, of people telling me what my goals should be.
The idea is to use a copy stand, whether vertical or horizontal, style system with a dslr and a macro lens. The negative will be move on a flat surface so that small areas of the negative with be "scanned", perhaps with multiple exposures for extended dynamic range through HDR, and the tiles will be stitched together with something like panotools.
Some tests have been done and at least one prototype has been constructed. Both HDR and samples at 1:1 have given positive results. In addition various technical experts have been called upon, and the result is that this is a very viable project. Thus, I won't waste any more time arguing about feasibility.
The time has come to try things out and see what works. I hope that others beside Rick and I will also build something. If someone isn't interested in actively take part in testing, construction, or offering positive suggestions, I politely ask that they spend their time posting in other threads.
“You often feel tired, not because you've done too much, but because you've done too little of what sparks a light in you.”
― Alexander Den Heijer, Nothing You Don't Already Know
Peter, I appreciate your efforts on this. I think you are heading in exactly the right direction.
Thanks,
Kirk
at age 73:
"The woods are lovely, dark and deep,
But I have promises to keep,
And miles to go before I sleep,
And miles to go before I sleep"
+1 Thanks!
Peter, this has been done, is being done, and will be done better in the future - perhaps by you. I think if you search on medical image stitching, for example, you will see lots of stuff. Then there are the consumer products like Panavue. People have tried doing films with those and there are citations in the literature discussing the issues.
The technical aspects of seamless image montaging are formidable. Trying some commercial software will demonstrate that. You should be able to get a demo from someone who wants to sell you a montaging system. What about the GigaMacro thingie cited earlier? An hour with an existing system will give you a feel for what the issues are.
However, the stitching bit that the montaging system deals with is quite independent of your first point - whether or not the rectangular area detector in a camera can deliver quality better than the linear array in an Epson. Based on past experience, my prediction is no - but I would love to be wrong.
Hi Peter,
Thank you for your input. Part of the fact that much of this has been done before is a good reason for optimism. We are at a good place technologically at the moment, with digital cameras, diy robotics, hdr, and stitching technology making things practical that weren't just a short time ago.
Maybe I'm wrong, but I hope that the samples posted earlier in the thread speak to the achievability of goal #1.. See: http://www.largeformatphotography.in...=84769&page=11 Posts #105 and #108.
See also Rick's test at: http://www.largeformatphotography.in...=84769&page=17 post #170.
“You often feel tired, not because you've done too much, but because you've done too little of what sparks a light in you.”
― Alexander Den Heijer, Nothing You Don't Already Know
Peter, look at this exchange for Auto Pano Pro. I think there may be some help here for the software issue via "templates". I used to own this software but never tried this. It seems to allow you to tell the software how you shot the tiles which allows it to arrange the tiles appropriately regardless of detail content.
Thanks,
Kirk
at age 73:
"The woods are lovely, dark and deep,
But I have promises to keep,
And miles to go before I sleep,
And miles to go before I sleep"
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