ProOptics 12K Line Scan Lens
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ProOptics 12K Line Scan Lens
Ran into this lens at surplus shop, I was told it is a 12K line scan fixed focus lens made by Korean Prooptics. So I looked it up and found its specs:
http://www.prooptics.co.kr/AF12k1_25x.html
According to the spec, it has M44x1 thread at the end of it, so I had to order a custom part, converting M44x1 to M52x0.75, then I used a M42-to-M52 filter ring adapter then mount it on some extension tubes to make it at 1.29X.
Test setup is as below: 3 degrees of freedom (roll, tilt, and yaw) on the subject and one degree of freedom on the camera (forward and backward).
With some tinkering with those 4 degrees of freedom, I got a picture as close I can. I think the "fuzziness" in the picture is due to bad printing, rather than focus. So maybe Robert's silicon wafer is good test here as the etchings are razor sharp.
I think it is pretty good corner to corner (except vignetting pointed by arrow, probably caused by my tubing -- in the spec it says CCD size of 86mm).
http://www.prooptics.co.kr/AF12k1_25x.html
According to the spec, it has M44x1 thread at the end of it, so I had to order a custom part, converting M44x1 to M52x0.75, then I used a M42-to-M52 filter ring adapter then mount it on some extension tubes to make it at 1.29X.
Test setup is as below: 3 degrees of freedom (roll, tilt, and yaw) on the subject and one degree of freedom on the camera (forward and backward).
With some tinkering with those 4 degrees of freedom, I got a picture as close I can. I think the "fuzziness" in the picture is due to bad printing, rather than focus. So maybe Robert's silicon wafer is good test here as the etchings are razor sharp.
I think it is pretty good corner to corner (except vignetting pointed by arrow, probably caused by my tubing -- in the spec it says CCD size of 86mm).
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A little geometry and algebra will yield a 3/2 ratio medium format sensor of ~40.77mm by ~27.18mm with 3.398 micron square pixels which will fit Nikon's new Z mount (49mm diagonal) will give ~96MP.
This is certainly within the reach of modern sensor technology, and I'm betting we'll see a Nikon medium format sensor camera based upon the new Z mount in the coming years, maybe not 96MP for starters but possibly ~58.56MP with D850 size pixels (4.35um).
Best,
This is certainly within the reach of modern sensor technology, and I'm betting we'll see a Nikon medium format sensor camera based upon the new Z mount in the coming years, maybe not 96MP for starters but possibly ~58.56MP with D850 size pixels (4.35um).
Best,
Research is like a treasure hunt, you don't know where to look or what you'll find!
~Mike
~Mike
This is for a very large sensor, 83mm across, with 7um pixel size. It isn't designed for small pixels or high-megapixel normal-sized sensors. That's why it has a relatively slow aperture.
A 35mm sensor that would match the design specification should be about 5000 pixels across. In other words, your Sony sensor is outresolving the lens.
Still, nice results!
A 35mm sensor that would match the design specification should be about 5000 pixels across. In other words, your Sony sensor is outresolving the lens.
Still, nice results!