p.2 #1 · Should M-to-E adapters be 9.80mm or 9.74mm?
phigment wrote:
My original design had the smaller tolerance at 9.7mm and could at times come out to 9.78. This was mainly due to the 4 component stack up (2 mounts, one separator and one circuit board.
The newly designed e-mount adds adjustment screws (no shims required!) to allow for fine tuning. All the new adapters I send out will be set to a nominal 9.80 mm.
turnstyle wrote:
Very interesting! And, finally, an adapter that can be adjusted without resorting to MacGyver-ism.
Do you have a list of changes from your previous design? When do you expect them to be ready?
And Paul is offering those of us with the existing Phigment Adapter the option of sending in our adapters to be updated to the improved version. Thank you very much Paul.
p.2 #2 · Should M-to-E adapters be 9.80mm or 9.74mm?
As far as my own experience with adapters and lens mounts, I believe adapters should be the correct thickness never thinner. Most lenses have negligible focus shift due to residual spherical aberrations, and some have less than negligible one. A lens that is not able to reach infinity wide open, will reach it stopped down, and not only because of DOF, but because focus plane is shifting backwards. Many lenses are factory calibrated to reach infinity stopped down but to fail to reach it wide open to account for focus shift. It is easy to check with LV.
p.2 #3 · Should M-to-E adapters be 9.80mm or 9.74mm?
edwardkaraa wrote:
As far as my own experience with adapters and lens mounts, I believe adapters should be the correct thickness never thinner. Most lenses have negligible focus shift due to residual spherical aberrations, and some have less than negligible one. A lens that is not able to reach infinity wide open, will reach it stopped down, and not only because of DOF, but because focus plane is shifting backwards. Many lenses are factory calibrated to reach infinity stopped down but to fail to reach it wide open to account for focus shift. It is easy to check with LV.
Thanks -- which adapters do you believe achieve correct thickness?
I'm rather surprised at how many seem to be shooting for 9.72mm, when the correct distance should be 9.80mm -- even the most expensive ones.
p.2 #4 · Should M-to-E adapters be 9.80mm or 9.74mm?
edwardkaraa wrote:
As far as my own experience with adapters and lens mounts, I believe adapters should be the correct thickness never thinner. Most lenses have negligible focus shift due to residual spherical aberrations, and some have less than negligible one. A lens that is not able to reach infinity wide open, will reach it stopped down, and not only because of DOF, but because focus plane is shifting backwards. Many lenses are factory calibrated to reach infinity stopped down but to fail to reach it wide open to account for focus shift. It is easy to check with LV.
But the question here is, "what is the correct thickness?". If Novoflex determined that the mount is indeed 18.05mm instead of the claimed 18.00 mm, then the adapter would need to be 9.75mm instead of 9.8.
p.2 #5 · Should M-to-E adapters be 9.80mm or 9.74mm?
phigment wrote:
But the question here is, "what is the correct thickness?". If Novoflex determined that the mount is indeed 18.05mm instead of the claimed 18.00 mm, then the adapter would need to be 9.75mm instead of 9.8.
Hasn't Sony released 18.00mm as spec for use by 3rd party e-mount lens manufacturers?
It sure would be interesting if it's actually 18.05mm in the spec document.
p.2 #6 · Should M-to-E adapters be 9.80mm or 9.74mm?
I personally would go with an adapter of the correct theoretical thickness. Whatever Novoflex measured can be due to sample variations, model variations (due to sensor cover thickness), or just measurement error.
p.2 #7 · Should M-to-E adapters be 9.80mm or 9.74mm?
edwardkaraa wrote:
I personally would go with an adapter of the correct theoretical thickness. Whatever Novoflex measured can be due to sample variations, model variations (due to sensor cover thickness), or just measurement error.
Me too -- but up until this morning, I would have assumed Novoflex would be the most likely adapter to be of correct theoretical thickness.
Anybody happen to know which adapters actually shoot for the correct theoretical thickness?
p.2 #8 · Should M-to-E adapters be 9.80mm or 9.74mm?
turnstyle wrote:
Me too -- but up until this morning, I would have assumed Novoflex would be the most likely adapter to be of correct theoretical thickness.
Anybody happen to know which adapters actually shoot for the correct theoretical thickness?
I haven't measured my Novoflex and Voigtlander M/E adapters, but from prior experience with several adapters of different mounts my bet is for Kindai/Rayqual that have always measured correctly.
p.2 #9 · Should M-to-E adapters be 9.80mm or 9.74mm?
edwardkaraa wrote:
I haven't measured my Novoflex and Voigtlander M/E adapters, but from prior experience with several adapters of different mounts my bet is for Kindai/Rayqual that have always measured correctly.
I'm unfamiliar with Kindai/Rayqual -- where do you get them?
p.2 #10 · Should M-to-E adapters be 9.80mm or 9.74mm?
You can buy them from Cameraquest. That's where I got my Rayqual Leica R-> Canon EF adapter. It is spot on, and well made.
I have a Novoflex Leica M -> Canon M adapter and indeed it's a pip over infinity focus which though inconvenient for easy infinity shots, it's better than being too short in case a combination doesn't work. That would be galling!
p.2 #12 · Should M-to-E adapters be 9.80mm or 9.74mm?
edwardkaraa wrote:
Also Rayqual has announced their M/E adapter vignettes with FF sensors, that is why I didn't order it. They are working on a new design.
Does anybody happen to have a photo of this adapter? I'm curious why it would vignette -- if other regular adapters don't. Does is have a relatively narrow inside diameter?
p.2 #13 · Should M-to-E adapters be 9.80mm or 9.74mm?
If I'm not mistaken, the official registry distance for the M mount is 27.76 mm. (measured from the film rails on a Leica M film camera ). Therefore, any adapter to NEX thicker than 9.76mm. would prevent reaching infinity focus. That is, if the NEX registry is exactly 18.00mm.
Anyway, to be safe, I wouldn't get adapters above 9.70-9.72mm. More often than not a lens or a camera body are slightly off specifications. Besides, you rarely have a perfect gapeless fit on the interfaces lens/adapter and adapter/camera. 0.01 or 0.02mm here and there are enough to spoil the party.
I wouldn't worry for possible problems with lenses having floating elements. It's very unlikely that anybody can detect the slightest trace of image degradation if the glass elements are 0.05 or 0.1mm. nearer to the focal plane.( several millimeters would be, of course, another thing )
Does anybody happen to have a photo of this adapter? I'm curious why it would vignette -- if other regular adapters don't. Does is have a relatively narrow inside diameter?
Thanks!
www.Rayqual.com
There are plenty of photos, but the site is in Japanese.
p.2 #19 · Should M-to-E adapters be 9.80mm or 9.74mm?
dcjs wrote:
Wouldn't the measured mechanical flange distance be off anyway because of the unknown thickness and refractive properties of the filter stack altering the length of the optical path? Just taking a camera and measuring the distance from the mount to the sensor seems to be a bit of a too simplistic approach for digital cameras.
Exactly. Then you have to ask which distance you are going to optimize for, a ray that is orthogonal to the imaging plane, or one that is incident and going to have it's optical path length changed by refraction. Field curvature is a real thing with non-telecentric lenses.
p.2 #20 · Should M-to-E adapters be 9.80mm or 9.74mm?
Ummm, I think all of my adapters are like 0.5 mm too thin (not measured, but checking where infinity focus really is with a lens attached). 0.05 mm is not gonna make any difference at all.
