RMS extension tube - sourcing
Moderators: rjlittlefield, ChrisR, Chris S., Pau
-
- Posts: 5
- Joined: Fri Jan 04, 2019 3:49 pm
- Location: Manchester UK
- Contact:
RMS extension tube - sourcing
I am using a Canon 20 mm 3.5 macro lens (which has an RMS thread) on a Canon bellows. But the bellows bulk makes lighting difficult.
Does anyone know where I can get a tube, say 30-50 mm long, with RMS threads, male and female either end? ebay etc throws up very short Chinese versions.
Thank you
Does anyone know where I can get a tube, say 30-50 mm long, with RMS threads, male and female either end? ebay etc throws up very short Chinese versions.
Thank you
-
- Posts: 3438
- Joined: Sat Nov 20, 2010 10:40 am
- Location: Santa Clara, CA, USA
- Contact:
I like Ray's idea about using a cone-shaped adapter with a bellows--and echo his point about flocking it.
Also, you can assemble an RMS extension tube of nearly any length you wish by combining Thorlabs SM1 (one-inch diameter) tubes with Thorlabs Optical Component Thread Adapters.
A similar line of tubes and adapters is available from Edmund Optics, but the cost will probably be higher. Both companies make excellent products, with Edmund being a bit more posh. Newport and others may also have parts to assemble what you need. This said, I would mainly look at Thorlabs.
These assemblies should also be flocked.
--Chris S.
Also, you can assemble an RMS extension tube of nearly any length you wish by combining Thorlabs SM1 (one-inch diameter) tubes with Thorlabs Optical Component Thread Adapters.
A similar line of tubes and adapters is available from Edmund Optics, but the cost will probably be higher. Both companies make excellent products, with Edmund being a bit more posh. Newport and others may also have parts to assemble what you need. This said, I would mainly look at Thorlabs.
These assemblies should also be flocked.
--Chris S.
-
- Posts: 1527
- Joined: Mon Jan 15, 2018 9:23 pm
- Contact:
Wemacro offers M42 tubes which are already flocked.
https://www.wemacro.com/?product_cat=ex ... ro&paged=3
I have a set, they are far better than those cheap ebay ones.
https://www.wemacro.com/?product_cat=ex ... ro&paged=3
I have a set, they are far better than those cheap ebay ones.
-
- Posts: 3438
- Joined: Sat Nov 20, 2010 10:40 am
- Location: Santa Clara, CA, USA
- Contact:
The cones are ~52mm long, so if 50mm is the absolute max, I agree, but they are pretty convenient having both extension and adapting in one shot. You'll need to flock most anything you put on there.ChrisR wrote:I'd wouldn't use the cones for a 20mm lens which you have to get close to the camera, they're too long (as well as shiny!).
-
- Posts: 3438
- Joined: Sat Nov 20, 2010 10:40 am
- Location: Santa Clara, CA, USA
- Contact:
Would Edmund Optics T-Mount Extension Tubes, with their M42 x 0.75 threads, substitute for T2 tubes? If I recall correctly, the main difference between the T-mount and the T2 mount is the latter's rotatability, which would not be needed for every application.ChrisR wrote:T2 tubes aren't too easy to find
--Chris S.
-
- Posts: 111
- Joined: Sun Mar 22, 2009 9:52 pm
- Location: Como West Sydney Australia
- Contact:
Canon made a series of M39 Flocked extension tubes that were used with a Leitz mount, they could be suitable
Check it out here
Using Wemacro 46C Clamps to hold Infinite Tube Lens
http://www.photomacrography.net/forum/v ... highlight=
Check it out here
Using Wemacro 46C Clamps to hold Infinite Tube Lens
http://www.photomacrography.net/forum/v ... highlight=
ChrisR wrote:T2 tubes aren't too easy to find
I was using T2 just to describe the thread, which is same M42x0.75 between T and T2.Chris S. wrote:Would Edmund Optics T-Mount Extension Tubes, with their M42 x 0.75 threads, substitute for T2 tubes?
The ones you linked to will naturally work, but there are cheaper ones as well: Ebay search gives just a few hits, but the set of 5, 10, 15 and 20 mm tubes ... or a few of them will work in many cases and the price is right.
On the other hand, sometime ago I couldn't find such sets for M42 - only few isolated ones. Thus I ended up with T2.
After I had the tubes fixed, I got the Raynox, step-up 42->43 and step down 49->42. Male and female reversing rings for T2 are also on their way, so that should take care of that. All I need is to order Mitutoyo...
I see there is now a 5-10-15-10m "T" threaded cheap set, I hadn't seen that. Ebay item 183195679508 seems to be all you'd need. The same seller does a 45mm tube.
The Canon 20mm f/3.5 needs short extension for its relatively limited useful magnification range. From 4 or 5x, better options are available, and below that, the working distance is rather short even though it performs very well.
The most suitable thing I have for that, which I have praised before, came from William at Wemacro, though I don't see it on his site now. That was a male M42 tube with a female M42 tube, each with an extended thread, and a locknut. Effectively it's a short rigid helicoid for about 20 - 40mm.
I (probably like many of us) have a few M42 tubes which go down to very short lengths, which are very cheap and fine for up to say 25mm.
A flat M42 adapter on the RMS thread doesn't significantly restrict the light getting to the subject, if at all.
I have a few T2 threaded bits and pieces, but generally I regard it as a nuisance!
The Canon 20mm f/3.5 needs short extension for its relatively limited useful magnification range. From 4 or 5x, better options are available, and below that, the working distance is rather short even though it performs very well.
The most suitable thing I have for that, which I have praised before, came from William at Wemacro, though I don't see it on his site now. That was a male M42 tube with a female M42 tube, each with an extended thread, and a locknut. Effectively it's a short rigid helicoid for about 20 - 40mm.
I (probably like many of us) have a few M42 tubes which go down to very short lengths, which are very cheap and fine for up to say 25mm.
A flat M42 adapter on the RMS thread doesn't significantly restrict the light getting to the subject, if at all.
I have a few T2 threaded bits and pieces, but generally I regard it as a nuisance!
Chris R