First low(ish) cost RF lens adaptors.

jolyonralph

Game Boy Camera
CR Pro
Aug 25, 2015
1,423
944
London, UK
www.everyothershot.com

jolyonralph

Game Boy Camera
CR Pro
Aug 25, 2015
1,423
944
London, UK
www.everyothershot.com
They are all CNC milled these days, so the chances of poor parallelism and loose tolerances are way lower than before. And these are not especially cheap ones either - not like the plastic 5 euro adaptors you can find for NEX etc.

I'm going to get the Nikon and FD adaptors and I'll report back on how good they are.
 
Upvote 0
Mar 25, 2011
16,848
1,835
They are all CNC milled these days, so the chances of poor parallelism and loose tolerances are way lower than before. And these are not especially cheap ones either - not like the plastic 5 euro adaptors you can find for NEX etc.

I'm going to get the Nikon and FD adaptors and I'll report back on how good they are.

How will you determine if the ends are parallel?

CNC machining does help, but making sure the opposite ends are parallel is a difficult process, since minute differences in the machinery can introduce errors. a few ten thousandths of a inch can be out of tolerance. I've worked with machined parts, it can be very difficult to measure some things to precise dimensions, for example, we could not find a accurate enough measuring device to confirm the accuracy of parallel holes anywhere in Los Angeles and had to design a secondary method to detect misalignment of fiber optic connector machined holes.

These parts are not in the same ballpark as far as accuracy is concerned, but still a concern if someone unknown is turning them out on a garage lathe. I currently import machined parts from China, its difficult to keep them consistent and accurate from shipment to shipment. I had a shipment last year that I had to adjust part by part due to inaccuracies, the next shipment was exceptionally accurate.

Canon has said that they keep manufacturing of mounts in house because of the tight tolerances required.
 
Upvote 0

jolyonralph

Game Boy Camera
CR Pro
Aug 25, 2015
1,423
944
London, UK
www.everyothershot.com
How will you determine if the ends are parallel?

I'll take some photos and see whether the results are satisfactory!

While there may be theoretical problems with adaptors, the proof is simply the quality of image that it allows.

So far I've had good results with even the cheapest of third-party adaptors. Call it luck if you will, but it's not a huge loss if it doesn't perform.
 
Upvote 0
Mar 25, 2011
16,848
1,835
I'll take some photos and see whether the results are satisfactory!

While there may be theoretical problems with adaptors, the proof is simply the quality of image that it allows.

So far I've had good results with even the cheapest of third-party adaptors. Call it luck if you will, but it's not a huge loss if it doesn't perform.

That's fine, but perceptions of performance are different for different people. What looks great to me may look bad to someone else. If a product meets my expectations, then I will use it, but if its something that I have no ability to measure, than I announce that its just my opinion, and others can state theirs.

The affect of accuracy is not just a theory, they are a measurable fact, as are the effects on a image. The effect on a image may be in proportion to the amount of error, it may be hidden by DOF, or at the corners or edges where its difficult to see, but its still factual.
 
Upvote 0
Dec 25, 2012
750
376
That's fine, but perceptions of performance are different for different people. What looks great to me may look bad to someone else. If a product meets my expectations, then I will use it, but if its something that I have no ability to measure, than I announce that its just my opinion, and others can state theirs.

The affect of accuracy is not just a theory, they are a measurable fact, as are the effects on a image. The effect on a image may be in proportion to the amount of error, it may be hidden by DOF, or at the corners or edges where its difficult to see, but its still factual.

Yes, you are right on all points but the photos of my breakfast and dog are likely to be sharp enough for me. ;)
 
Upvote 0