bemei wrote:
I do repro for a living, um, we use f8. Even if you have an extremely well corrected lens, at repro distances, shooting at wide apertures such as f2.8 you better be sure you can achieve 0.01 degree angle parity in all planes from the camera to the artwork. Especially once you get to true macro distances. Otherwise it's nothing to do with the lens and everything to do with DOF. Add 100 megapixels and a good geared head and a well calibrated digital level are simply a must.
The advantages of a 100 megapixel MF camera are resolution in a world where some high end clients are now demanding 600DPI scans rather than the older 300DPI standard, The difference between a 60 megapixel and 100 megapixel camera at 600DPI is an A4 to A3 document (including ruler/color chart) at 600DPI which is significant. The other big difference is the 4:3 crop which is better for flat originals such as documents, manuscripts, etc, it's rare that originals are in the 2:3 format and you end up throwing significant resolution away from the sides with the crop. ...Show more →
Absolutely agree. When working and before scanners I took thousands of flat copy shots with Nikon and micro nikkors, never used anything wider than 8, even a specialist lens needs that for the best performance. Certainly never found a 'general purpose' lens that was good enough for that dort of thing let alone a fast one. Curvature of field the biggest enemy as well as corner sharpness.
Still have 55 and 100mm Micro Nikkors, tried the Fuji 60mm on the FX cameras, not good enough.
At one time did 1:1 on 20x16 lith film for printing plates on a process camera, f/64 at least!
bemei wrote:
I do repro for a living, um, we use f8. Even if you have an extremely well corrected lens, at repro distances, shooting at wide apertures such as f2.8 you better be sure you can achieve 0.01 degree angle parity in all planes from the camera to the artwork. Especially once you get to true macro distances. Otherwise it's nothing to do with the lens and everything to do with DOF. Add 100 megapixels and a good geared head and a well calibrated digital level are simply a must.
The advantages of a 100 megapixel MF camera are resolution in a world where some high end clients are now demanding 600DPI scans rather than the older 300DPI standard, The difference between a 60 megapixel and 100 megapixel camera at 600DPI is an A4 to A3 document (including ruler/color chart) at 600DPI which is significant. The other big difference is the 4:3 crop which is better for flat originals such as documents, manuscripts, etc, it's rare that originals are in the 2:3 format and you end up throwing significant resolution away from the sides with the crop. ...Show more →
Of course. ^^^
The minute the OP indicates he does flat field imaging hand-held, I knew this post was bogus. There are so many minute variables that 1) hand-held is impossible to keep parallelism, and 2) no lens has adequate corner to corner resolution AND lack of light falloff wide open, even the best copy lenses of the day. Which 3) have no focus mounts and are used in conjunction with bellows, aka variable extension tubes.
The OP’s obvious lack of knowledge is shouting here, or he’s already got the knowledge and is trolling.
The minute the OP indicates he does flat field imaging hand-held, I knew this post was bogus. There are so many minute variables that 1) hand-held is impossible to keep parallelism, and 2) no lens has adequate corner to corner resolution AND lack of light falloff wide open, even the best copy lenses of the day. Which 3) have no focus mounts and are used in conjunction with bellows, aka variable extension tubes.
The OP’s obvious lack of knowledge is shouting here, or he’s already got the knowledge and is trolling.
Or the fact that the OP refuses to show any of his work, let alone his test shots.
mdude85 wrote:
Or the fact that the OP refuses to show any of his work, let alone his test shots.
A theorist who thinks things should work fine the way he believes a perfect optical system would behave? Clearly he has no experience at all with the real world of imaging...
