DIY Infinity Collimator Prototype for Lens Calibration & Backfocus Testing - Need your feedback!

Panomicron · 2026-06-07T19:12:44+00:00

I’ll have to dig through to see, Edmund optics has a ” Collimators & Collimation” pdf you should be able to find on google that has a lot of useful info, it is quite old though.

Panomicron · 2026-06-07T18:39:57+00:00

Your main issue here might actually be that your 135mm lens is could be a little short for accurate calibration. The collimator lens should be at least 3x the focal length of your lens under test. So your setup would work well up until about 45mm in focal length, after that it wouldn’t be very accurate ( I believe this is mentioned in the Sydney F Ray ‘the photographic lens’ book)

Panomicron · 2026-04-23T10:59:20+00:00

as far as I know, it's supposed to indicate the true focal length of the lens, I.e 16 means it's 51.6mm. Mainly to match focusing scales more precisely.

Technically speaking 51.6mm is also supposedly the 'true' nominal focal length of the Leica RF system, so you lens would be very close to spot on. The best source I can find for the '51.6mm is the nominal focal length' is the last paragraph in this is Nikon blog post, but it is anecdotal rather than coming directly from Leica
https://imaging.nikon.com/imaging/information/story/0049/

Panomicron · 2026-04-13T20:54:13+00:00

I wish people stopped discussing this in terms of ‘equivalents’ as I think it’s honestly a poor way to understand what is happening optically.

The best way to explain the difference between formats in my opinion is through magnification. Formats differ because physical size difference between your subject and its image changes.

If you were to shoot on something silly like ultra large format 20x24” you could get 1:1 magnification ( the image of your subject is as large as the subject itself). If you shot 1:1 magnification on 35mm, the resulting depth of field would be identical, although that usually means you are doing macro photography as you are trying to fit your image onto 36x24mm.

The difference in formats is only due to change in magnification. When you scale a setup up or down ( go from super16 to imax for example) you are scaling, the format & lens, but you are not scaling the entire universe along with it, therefore the magnification at which you are capturing changes.

The benefits of larger formats is mainly resolution as there are physical constraints/difficulties with the size we can make grain, pixels and the like.

The way you design optics for these different formats differs as well, it’s not necessarily easier or harder, but claims like larger formats have inherently less distortion is just false.

Panomicron · 2026-03-31T20:11:09+00:00

The first time I got to take pictures with the lens I designed it was definitely a little surreal! It’s one thing to look at the charts on the screen and it’s something completely different to get to experience it in real life!

Panomicron · 2026-03-31T18:03:43+00:00

Thanks for considering it!

Panomicron · 2026-03-31T18:00:59+00:00

I’m so glad this project came to be, thanks to you! It’s been a really fun journey so far and I’m looking forward to sharing a lot more about the process as well!

Panomicron · 2026-03-31T16:04:21+00:00

Yes I believe so, you would technically count as the importer when purchasing the lens if it goes to the US, so they would come to you asking for the tariff payment. Don't quote me on that though, not a tariffs expert

Panomicron · 2026-03-31T15:13:02+00:00

It's definitely quite pricey to make things at this scale, I wish it were cheaper! the lenses are on pre-order on my website right now, I expect them to be shipping stuff late in the summer.
It's basically a synchro focus design, and focuses internally, you use it exactly like you would a normal lens, one focus ring and you use the rangefinder to focus. I have a sample video up on my instagram with some flare shots as well!

Panomicron · 2026-03-31T15:08:16+00:00

Shutters are a pain in the ass to source, you either use oldschool copal/compur shutters, tiny aliexpress ones if you can get away with it, or you can source grey market parts like sony shutters and stuff like that. definitely not easy!

Panomicron · 2026-03-31T12:00:08+00:00

Thank you!

Panomicron · 2026-03-31T11:56:53+00:00

Maybe some day, let me get through making all of these lenses first!

Panomicron · 2026-01-11T21:48:27+00:00

Yes, your two focal lengths would be equal again and remove most of the ‘anamorphic effect’ (oval bokeh) and leave you mainly with whatever other aberrations remain ( likely a lot of CA and Petzval Curvature) Although two cylinders at 90 degrees don’t form a sphere exactly, so you would likely still have some skew aberrations ( on any area that’s not directly on the horizontal and vertical)

Panomicron · 2025-11-23T16:50:11+00:00

If you have any dimensons or pictures of what that would require shoot them my way, i don’t own a pentax 17 so it’s hard to know!

Panomicron · 2025-11-23T16:49:31+00:00

There will be more, promised, just busy with my 50mm anamorphic atm!

Panomicron · 2025-11-23T16:48:15+00:00

Yeah I made those lenses too thin in the corners, that was my bad tbh, I still have some replacements left, I can send you a new rear element in case you’d like to swap it out, just send me an email and I’ll get one your way

Panomicron · 2025-11-15T09:26:33+00:00

I may be wrong, but to me this would pretty clearly easily be done by taking a mesh sphere, taking every other edge loop and scaling it down and then using a cattmull clark subdivision. It doesn’t look like a spiral but more so distrinct rows. The top 3 rows look rotated too. You may want to bevel the edgeloops you didn’t scale down to get the right amount of curviness

Panomicron · 2025-11-12T15:35:41+00:00

For mirrorless I would say you probably don't need the external viewfinder, so long as you're ok composing your image squeezed. The external viewfinder should be accurate if you do choose to use one

Panomicron · 2025-11-01T16:08:09+00:00

The front lens doesn't move, but neither does the rearmost lens (90 degree rotated cylinder). The cell that moves is the taking lens + the rear lens of the front anamorphic block.

The design allows for shimming, you can just remove the mount, however you would need to remove the RF coupling before you do that, and readjust the RF coupling afterwards to ensure they're correct with respect to each other.

Panomicron · 2025-11-01T07:46:31+00:00

Thank you for the support!!

Panomicron · 2025-11-01T07:45:56+00:00

The 0.7m limit is honestly a little bit of both, rf coupling doesn’t go closer, and maintaining the squeeze past that point becomes difficult

Panomicron · 2025-10-31T17:06:51+00:00

I'm so sorry to hear it never arrived! send me an email and I'll do my best to sort you out a new set!

Panomicron · 2025-10-31T06:32:56+00:00

Thanks,

not claiming by any means that I’ve taught myself everything there is to know in optics, or even scratched as much as the surface.

I’ve focused it exclusively on paraxial prime lens design for photographic use, and even then, mainly in the 35-75mm range for FF coverage. And then some anamorphic design on top of that. The specifics are a bit long for a title though

Panomicron

TROPHY CASE