I posted a link, earlier in this thread, for a software controlled, threaded rod, stepper motor driven stage, which would cost less than $100...
I posted a link, earlier in this thread, for a software controlled, threaded rod, stepper motor driven stage, which would cost less than $100...
Sorry Joseph, my memory is questionable. I'll look for the link.
Basically, what I've been doing is investigating options. I'm not advocating any one system. The idea is to come up with some possibilities, hoping that they might either turn out to be viable, or provide insight into what might be viable. We have a lot of experimenting and investigating of what to do, and I expect that people will come up with and build various designs. For example, I expect that what would work well with 4x5 negatives might not be the same hardware that works well with ULF negatives.
“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
This surprises me:
New Plustek Scanner
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"
I'm looking into doing ULF, but I doubt if I'd want to scan that, that would be for reproduction at same size. I think 8x10 would be the largest size anyone would seriously want to enlarge, although the exception will prove the rule...
I think two sizes, up to 4x5, and up to 8x10, would be all that would be necessary- if someone wanted to go bigger, then it could be scaled up-
Could you repost? It seems to have gone missing.Originally Posted by jb7
I just recieved a linear slide from Igus, http://www.igus.com/wpck/default.asp...filmtechnology. It's 1 meter long and price was about $125. I think it would work quite well for this application.
This was the post I made, in relation to the positioning stage, which could be adapted from the 3d printer linked to above-
Thinking about it further, and taking account of the depth of field requirements as stated earlier, I'm not sure that any of these approaches are on the right track. There's got to be a better way...
That's a good looking rail...
I built a support structure today, and hopefully I'll be able to take some tests with my 55 micro tonight, if I can get everything aligned. That's non-trivial. I also bought an inexpensive 4x microscope objective, one that the macro folks have had good results with, but I'll have to wait until an RMS adapter arrives to give it a try.
“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, if you have a chance post some pictures of the setup. I would love to see what you come up with. I am working on finishing some other projects right now, but plan on making my own prototype as well.
Since I work in a metal/machine shop I think I can make a nice sturdy prototype without too much trouble. I am also learning about programming micro controllers like the Arduino, and eventually want to make an automated stage for the film. It seems the programming for the stepper motors isn't too complicated, however I am still learning and it may take awhile before I have something working. I'll keep everyone posted of my progress once I get going on it.
Evan
Hi Evan,
That sounds terrific! Please keep us updated.
Here a full-frame picture from the 55 nikkor at 1:1:
Below is a crop to the bible:
And finally an up-close crop of the text:
“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
I've conducted my own proof of concept, and I think there is real potential.
I tried it with my Tamron SP 90mm macro, which is outstandingly sharp...in the middle of the frame. Or perhaps the field is not quite flat. In any case, it broke down in the corners. So, I switched to an EL-Nikkor 105/5.6. I have it mounted on a Pentacon Six body cap, which is mounted in a Pentacon Six bellows, and then mounted on my Canon 5D MkI using an adapter. I mounted the camera on a tripod adjusted to lean over my light table, and then used a telephoto lens stabilizer cradle from the front of the bellows to rest solidly on the light table. Focusing was...difficult. The camera needs f/5.6 for focus confirmation, and at near 1:1, the light getting to the camera was more like the equivalent of f/11. I used an eyepiece magnifier, and I have a Maxwell screen in my Canon which helps with focusing manually. I made exposures at f/5.6, f/8, and f/11, and f/11 was the best of the lot, once I figured out how to stabilize the camera.
My light table is a cheapie, and would not at all be evenly illuminated enough for this application. But it worked okay for the test. I just laid the negative on the light table.
The first image is a scan of the whole image made in the Epson V750 at 2400 spi. I adjusted the image according to my usual workflow. I made the photograph some years ago of a portion of the famous front door of the Espada Mission in San Antonio. Lens was a Schneider Super Angulon 121mm f/8, at f/32 with a 1-second exposure on FP4, developed in HC110 Dilution B to n+1. At f/32, there is a touch of visible diffraction, but that's what I needed for depth of field--that stone wall is a foot thick. I've made an enlarger print of this negative at 16x20, and it is extremely sharp at that print size.
The upper half of the second image is a full 24x36mm photograph of a piece of that image made using the 5D with the EL-Nikkor enlarging lens, as described above. Actual magnification was not quite 1:1--more like 1:1.15--which was as racked out as that bellows will go. I need a short extension tube (which I could not put my hands on at the moment) to get it all the way to 1:1. The effective resolution of the scan is 2670 spi--just a little more than the Epson. For comparison of general tonality, I've included the same piece of the image snipped from the Epson scan in the lower half. It's a bit smaller because of the difference in resolution. Yes, the upper image looks smoother and clearer to me, too.
I inverted the image and adjusted curves. I then applied a small amount of sharpening (0.8 radius at 100) to try to match the effect with the Epson. There is no sharpening at the downsampled resolution. Out of the Canon 5D, the histogram only covered the middle third of the tonal range output by the camera. I use RAW and expanded the range somewhat during the raw conversion, and then more in Photoshop.
The third image is the scan using the Canon 5D/EL-Nikkor shown in actual pixels. The fourth image is the scan using the Epson shown in actual pixels. There is no doubt that the Epson's butt is getting kicked here. Yes, the scan using the DSLR is a little bit lighter, which is, I think, a hot spot on my light table. But there is no doubt that the DSLR scan is seeing the tonality of the negative much better, and also retaining information in the thinner bits. And there is no doubt that grain is visible in the DSLR scan and not in the Epson scan.
What have we learned? 1.) This will work, even with modest cameras and affordable lenses. Enlarging lenses are good enough, at least at 1:1 or so using a camera with an 8-micron sensel. 2.) Rigidly mounting the camera is critical. My tripod alone was not sufficient--the camera required two points of support to be really stable. I used the self-timer to let the camera settle down before making the exposure, but it wasn't enough without two points of support, at least with the camera cantilevered over the light table. There is no question that moving the film will be the preferred approach rather than moving the camera. 3.) Forget autofocus. At f/11 (indicated) and 1:1, the camera is only seeing the equivalent of f/22, and the autofocus will not work. 4.) a lens with a flat field is critical. 5.) Dust is no less challenging with this approach than with any other. I spotted the Epson scan, but I didn't bother with the 5D scan and you can tell. 6.) I'm convinced that it is possible to significantly improve on an Epson V750 using this approach--my results seem to me a floor with lots of room to do better with the right apparatus.
Rick "less interested in what's possible with the state of the art and more interested in what's possible with what I already own" Denney
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