Every time I start to reply to this thread, more posts come in and it gets away from me. I was the friend who asked Rik about machining down the Raynox DCR-150. His initial impression is what made be think this lens would need to be disassembled for tight integration. But with benefit of Etalon's experience and Rik's re-examination, machining down the Raynox seems like a very good approach. I'd machine it to just slightly under 48.3mm, put it in a Thorlabs SM2 tube, and hold it in place with a pair of Thorlabs SM2RR retaining rings.
Here is what I wrote in my emailed correspondence with Rik:
- . . .the best way that comes to mind so far involves a bit of machining. A Thorlabs SM2 lens tube (such as the SM2L10, or something longer) has a clear aperture of 48.3mm. The knurled ring on the Raynox has a diameter of 53mm.
You have a good knowledge of lathes. Do you think it would be difficult to turn that knurled ring down to something just a bit smaller than 48.3mm?
If so, a pair of SM2RR retaining rings would hold it in place very nicely. This could form the basis of a nice integration similar to what I have for my MT-1. A nice thing about Thorlabs is that their parts are generally less expensive than Edmund Optics. But of course they have a largely overlapping (and largely non-compatible) suite of opto-mechanical components. At the simple end, it would be easy to mount the Raynox in a lens tube, put appropriate mounts at each end, slip the ring into ring clamps, mount the ring clamps on an Arca plate, and call it a day. But it would be easy to add an iris, analyzer, and beam splitter..
What you do is straightforward. Get a lens tube of the desired length. Screw a retaining ring into it where you want one end of the machined Raynox lens to be. Drop the machined Raynox into the tube so that it rests on the retaining ring. Screw another retaining ring into the tube until it holds the Raynox snugly in place. You may want a spanner wrench to screwing in the retaining rings. Thorlabs will sell you one sized for the SM2 tubes (making the tool a single-tasker), or you can buy an adjustable spanner wrench (get a good one, and you'll have a versatile tool). Here is what looks to be an excellent video on lens spanner wrenches (I've only had a chance to watch the first part so far).
The nice thing about Thorlabs tube components is their combination of high-quality and low price, and the availability of a huge range of adapters and other components that work with them. I'd suggest keeping your build as fully "all Thorlabs" as possible. (This is somewhat true with Edmund Optics as well--though the prices are somewhat higher and some components a bit more posh. I went with Edmund because integrating an official Mitutoyo tube lens is more straightforward with Edmund parts.)
In other details, Thorlabs makes a nice F-mount for your camera (part # SM2NFM2) that will screw right onto the SM2 tubes, which will be better than using the Nikon BR2a and Thorlabs SM2A52.
I'd suggest omitting the SM2V15 (13.5 mm + 33.3 mm variable extension) and using solid tubes. The solid tubes are cheaper and more importantly, will give you a stronger, less flexible assembly. (I got rid of the variable extension tube in my assembly--it wasn't horrible, but I prefer the assembly without it.) By mounting a machined Raynox between two retaining rings, you can position it very precisely inside the fully-threaded lens tube, so you won't need the variable extension tube.
On the front of your MT2 tube, place a Thorlabs SM2A adapter to go from the SM2 tube to SM1 (necessary for the M26 objective mount coming next).
In front of this, mount a SM1A27 - Adapter with External SM1 Threads and Internal M26 x 0.706 (Mitutoyo objective) Threads
Get several lens tube mounts to hold everything in place, and mount these on an Arca-style rail. Or better, mount them on a sturdy piece of aluminum right angle stock, and mount Arca rails on both exterior sides to permit both landscape and portrait shooting.
If you think you will ever want an iris, the ability to cross-polarize, or add a beam splitter for axial illumination, now is the time to plan for it--and you could do any of these pretty easily with Thorlabs parts.
--Chris
