Search found 200 matches
- Sun Jan 17, 2021 4:55 am
- Forum: Equipment Discussions
- Topic: Canon RF 70-200 f/2.8 L IS USM
- Replies: 0
- Views: 58
Canon RF 70-200 f/2.8 L IS USM
Has anyone had a chance to try the above lens as tube? It seems to me that the extending design might allow for larger usable range as tube lens than the old internal zooms. On the other hand, there is the distinct possibility of zoom creep in vertical setup. The optical construction is also a lot l...
- Mon Jan 11, 2021 10:51 pm
- Forum: Equipment Discussions
- Topic: Schneider-Kreutznach lens parameters
- Replies: 5
- Views: 176
Re: Schneider-Kreutznach lens parameters
Thanks Robert! I should have guessed they were yours - much of the useful stuff is. 

- Mon Jan 11, 2021 2:46 pm
- Forum: Equipment Exchange
- Topic: Sell: Photar 25mm f2.0
- Replies: 6
- Views: 186
Re: Sell: Photar 25mm f2.0
Thanks for the information. I'm interested in full frame corners, so I'll have to think about it a bit. If someone else takes it meanwhile ... I won't have to decide. 

- Mon Jan 11, 2021 11:37 am
- Forum: Equipment Discussions
- Topic: Schneider-Kreutznach lens parameters
- Replies: 5
- Views: 176
Schneider-Kreutznach lens parameters
I seem to recall seeing explanations for Schneider-Kreutznach lens parameters somewhere, but I can't find them now. Anybody have such a document they could share? f' eff is focal length, but what are the others? S F & S' F' are likely distances to focal point, but from where? From nodal points or el...
- Mon Jan 11, 2021 11:21 am
- Forum: Equipment Exchange
- Topic: Sell: Photar 25mm f2.0
- Replies: 6
- Views: 186
Re: Sell: Photar 25mm f2.0
Hi,
Did you use it with APS-C, full frame or some other size sensor?
Did you use it with APS-C, full frame or some other size sensor?
- Fri Jan 08, 2021 2:49 pm
- Forum: Equipment Discussions
- Topic: Raynox dcr150 custom tube lens
- Replies: 21
- Views: 725
Re: Raynox dcr150 custom tube lens
I suspect that painting the inside thread will lead to unpleasant amount of paint powder inside the system after you screw in the front tube. Not that the flocking would be any easier. What do you think if the outer tube had only 10 ... 20 mm of thread at the front end and the rest would have larger...
- Thu Jan 07, 2021 6:52 am
- Forum: Equipment Discussions
- Topic: Raynox dcr150 custom tube lens
- Replies: 21
- Views: 725
Re: Raynox dcr150 custom tube lens
Unfortunately that article doesn't give the distance from Raynox to sensor in the nominal position.
A quick measurement gives 202.8 mm. The Raynox was much shorter (15.5 mm) than I recalled. So It should be sufficient to use 205 mm as maximum length with reversed DCR-150.
A quick measurement gives 202.8 mm. The Raynox was much shorter (15.5 mm) than I recalled. So It should be sufficient to use 205 mm as maximum length with reversed DCR-150.
- Thu Jan 07, 2021 2:24 am
- Forum: Equipment Discussions
- Topic: Raynox dcr150 custom tube lens
- Replies: 21
- Views: 725
Re: Raynox dcr150 custom tube lens
Yes, Raynox DCR reverse. +/-2cm means between 18cm and 22cm will be good enough. I'm not entirely sure about that. I'm using it in forward position and the distance from sensor to the rear flange of Raynox is 210.6 mm. There is some uncertainty in that, but that shouldn't be more than 1mm. There mi...
- Wed Jan 06, 2021 9:48 am
- Forum: Equipment Discussions
- Topic: Raynox dcr150 custom tube lens
- Replies: 21
- Views: 725
Re: Raynox dcr150 custom tube lens
Instead of using a helicoid for distance A, I had the intension of machining 2 tubes sliding inside each other like a helicoid. If I make it 20cm and have +/- 2cm for fine adjustment, would that be enough ? and would you recommend that I mount the raynox150 reversed or not ? I would think that inst...
- Sun Dec 20, 2020 3:44 am
- Forum: Equipment Discussions
- Topic: Scanner Nikkor 38mm f/2.8 LS30 Scanner Lens Tested
- Replies: 49
- Views: 1564
Re: Scanner Nikkor 38mm f/2.8 LS30 Scanner Lens Tested
M42x0.75 would have been nice, though. :wink: There is very limited number of rings ending at female M42x1, but almost unlimited number ending with female T2 (M42x0.75). Always thought the opposite, M42x1 was more popular, I have been trying to sell a set of T2 x 25mm extension rings, 5 pieces, Sch...
- Sat Dec 19, 2020 5:03 am
- Forum: Equipment Discussions
- Topic: Scanner Nikkor 38mm f/2.8 LS30 Scanner Lens Tested
- Replies: 49
- Views: 1564
Re: Scanner Nikkor 38mm f/2.8 LS30 Scanner Lens Tested
The inner diameter of RMS is smaller than the D21.8 opening, so that would have to grab the lens from the end only.
M42x0.75 would have been nice, though.
There is very limited number of rings ending at female M42x1, but almost unlimited number ending with female T2 (M42x0.75).
M42x0.75 would have been nice, though.

- Fri Dec 11, 2020 3:42 am
- Forum: Equipment Discussions
- Topic: 8000ED Scanner lens mounting idea
- Replies: 7
- Views: 805
Re: 8000ED Scanner lens mounting idea
I supect it should be relatively easy to design and print two sleeves with conical surface between them. On would have full circumference cone and on the other the cone would be split to sections. Then use two fixing rings to tighten them around the scanner lens.
- Sun Dec 06, 2020 12:11 pm
- Forum: Equipment Discussions
- Topic: Setup for the Mitutoyo M Plan Apo 50x / 0.55
- Replies: 13
- Views: 1124
Re: Setup for the Mitutoyo M Plan Apo 50x / 0.55
Are you sure your dimensions are right? It seems that you are using Raynox reversed. I'm not, but the distance from sensor to the rear flange of Raynox was something like 210mm. In your picture the rear flange is roughly 230 mm from the back of the rear cap. The sensor is likely a bit further still....
- Sat Dec 05, 2020 11:32 am
- Forum: Equipment Discussions
- Topic: Setup for the Mitutoyo M Plan Apo 50x / 0.55
- Replies: 13
- Views: 1124
Re: Setup for the Mitutoyo M Plan Apo 50x / 0.55
As a matter of fact, you shouldn't expect very much resolution from 50x/0.55. Something like 1500px from APS-C is my guess.
- Wed Dec 02, 2020 12:47 pm
- Forum: Equipment Discussions
- Topic: Choice of processor
- Replies: 17
- Views: 2373
Re: Choice of processor
32 GB of RAM.
Note the difference in transfer speed. Is this about SSD performance? If your Sabrent is Rocket Q4, it shouldn't be.
Note the difference in transfer speed. Is this about SSD performance? If your Sabrent is Rocket Q4, it shouldn't be.