Hi Ken, I'm refering to magnification. A 1x scan is at 1:1 sensor size to subject size, a 2x is 2:1, a 3x is 3:1.....
Hi Ken, I'm refering to magnification. A 1x scan is at 1:1 sensor size to subject size, a 2x is 2:1, a 3x is 3:1.....
“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 had deduced that, and I gathered that your 35mm Tech Pan scan shows that film can definitely out-resolve a state-of-the-art digital camera. But thanks for making it clear. Again, this is very helpful to those of us with crap scanners who are trying to decide which way to go.Originally Posted by Peter J. De Smidt
Peter, I agree with your comment. I don't know the grain size typical of TP so I'm guessing a bit, but I've used it for photographing integrated circuit chips at 1X on 35mm TP and can't really see any grain well imaged on a 20X enlargement. The reason is that the taking lens resolution is the limiting factor. I was using an older 90mm Vivitar series one macro with the 1:1 adapter, an extreme;y high resolving power lens considering its age.
Looking at it another way TP grain size is in the range of 0.5µm to about 5µm (I'm estimating a bit) when developed using a fine grain developer. There are no 1:1 lenses that will resolve those dimensions; microscope objectives would be required. Are you sure you can see clear grain in TP at 1X using your 50 mm Componon S? I guess your TP neg. could be grainier than some I have done in the past. With an NA of around 0.1 the componon is limited in resolving power to the 5 to 10µm range (5µm is 100 lp/mm.) Clearly there would be no advantage in going to 3X for any practical purpose.
Earlier work with my test setup showed really adequate scans at 0.5X with the 90mm Vivitar macro. I would tend scan at 1X for a print up to about 30 X 40 inches and that exceeds what my Epson 750 can do by a very decent margin.
The real caveat in this scanning business is to find a high quality LF film where the image resolution on film is in the sub 20µm range to begin with. I tend to work with a COC of 20µm limit in setting a hyperfocal distance, but it is common to use 50µm or even 100 µm as a limit. The 20µm limit yields 80 µm on a 4X print for 16 X 20 from a 4X5.
BTW some great work there Peter, thanks.
Nate Potter, Austin TX.
I would need a set of step-by-step instruction written at the level of a third grader Just kidding--but I did have to google "Fritzing diagram" and "Arduino."
--Darin
Those searches are probably still in Peter's and my browser history. : )
I'm considering a dedicated D5200 with it's 3.9µ pixel pitch which would result in a potential 6512 dpi.
Here's a sample of scanned 4x5 Tech Pan, shot with a tripod mounted and cable released Crown Graphic and Xenar 135mm, technidol, captured at 1:1 with the D800E, using a Schneider Apo Macro Digitar 80mm f6.7 (donated to the project by a well regarded and unnamed benefactor : ) with nothing but default sharpening in Capture One, 100% of what that looks like after stitching with Sinc36 algorithm in PTGui (Run on sentence? Nah.):
The offer to scan for comparison stands for me as well, it's critical to the project. Tonality in various media and many other comparisons are still to be explored.
Warning, V700 rant:
I've owned a V700 and was content to toss each and every result of scanning small and medium format as they were crap. That's not to say I didn't loathe the 4x5 scans as well, but for smaller prints, yada yada yada.
Unless you are radical and earn your living by handheld shooting of your own fart bubbles in the bathtub, medium format simply deserves better than V700 resolution, IMVHO. I've revisited some of those earlier V700 scans and am content with the now very good if not excellent results.
Peter and I have taken entirely different approaches mechanically. There are still others waiting to be invented. As Peter's mentioned, the software and electronic aspects are worked out enough to allow for individual implementation, right now.
I also want to keep reiterating the colossal contribution of Richard Iles, without whom.. well, I don't want to think about it. : )
Last edited by Daniel Moore; 1-Oct-2013 at 01:42.
Nice work, Daniel!
One of the difficulties we face is that building our scanners requires a bit of equipment and skill. To build mine, for example, a well-aligned table saw and a drill press we're really helpful. If you have those, and know how to use them, then building a similar scanner shouldn't be a problem. If you don't have those tools or skills, then I'm not sure what I can do to help. I could work on building another scanner using parts that don't need those tools, perhaps using aluminum extrusions or threaded steel pipe, but I've already spent a tremendous amount of time and a fair bit of money on this project, and I have other things to do.
Daniel's more elegant design requires a higher level of skill to build.
“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
Borrowing from an existing support structure may be the fastest way to DSLR scanning. Though not quite yet 'existing', I think the frame from a Rigidbot 3D printer may work as a foundation for example.
From their website:
The RigidBot 3D design is fully expandable in the X, Y and Z directions. Using the injection molded plastic joints, you can adjust the size by swaping out the metal bars with longer or shorter ones (available at any hardware store or on our future online store).
Agreed. and reiterating my suggestion when this conversation was just a single thread... "rewrap reprap"
http://reprap.org/wiki/Main_Page
original box: darwin
http://reprap.org/wiki/Darwin
alternate: eiffel
http://reprap.org/wiki/Eiffel
the family tree:
http://reprap.org/wiki/RepRap_Family_Tree
How many people would build a kit? For instance, suppose there was something along the lines of: http://www.adafruit.com/products/1169, with some additional parts. If there was enough demand, we might be able to talk Adafruit (or similar) into putting together a kit. They already have most of the stuff needed. But my gut feeling is very few people would buy it. It would be too much of a pain for most people to build. The film plane has to be flat and parallel to the image sensor within a few thousandths of an inch. I have a precision square, straightedge, dial indicator, and a laser alignment device, and even with these tools, getting everything just right takes a lot of effort. If someone has those types of things, and is a machinist or wood worker, then those are the type of people who like to come up with stuff on their own. For those people, the biggest hurdle would likely be the control system, which Daniel and Richard have worked out and made public.
Perhaps a Kickstarter campaign would make sense. The goal would be for us to develop a kit from easily sourced materials, such as aluminum extrusions.... If we set a low goal, one that's just enough for us to buy all of the materials needed to figure this out, and we don't get funded, well, that would be our answer. If we do get funded, that might show Adafruit (or others) that there's a big enough demand.
“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
How many? slim.
anecdote: last summer ('12) I held a maker camp, along the lines of a build camp from the homebrew days of computing. It was held in Presidio county (out of the way ranch land), so that may explain the low numbers. High interest. A few dozen signups. At the end of the build, we had 4 units built.
This past summer, they built 3D printers and automatic watering systems. Those sessions were full.
[suggestion: kit for some of the mechanical; made, including connectors for any motion drive and control sections (sparkfun).. the alignment stage is the problem in mechanical]
[suggestion2: get one of the "photo workshop" centers to check interest for a summer workshop]
How about a kit based upon a popular enlarger. The enlarger light source provides illumination, and the existing structure (and adjustments) provide the parallelism. Best of all, there is an existing film holder apparatus, with lots of options for glass/glassless etc according to taste.
In an ideal world, the scanning frame could be mounted in two positions. Either on the enlarger head (perhaps with the head inverted and a camera mounted above it) so that the negative is moved through a spot of light created by the head. Or on the baseboard, and the camera is moved about photographing the projected image from a regular enlarging lens.
The first allows tighter control of the optics, but at a cost of complexity in the negative stage. It allows you to adjust focus on the fly if so needed. The second relies upon a good enlarging lens, and adequate alignment to maintain focus, but is a much simpler thing to build if you already have a working, well-aligned enlarger.
Anyway, congrats on the progress and success so far. Impressive stuff.
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