Raynox dcr150 custom tube lens

[Pau]

Don't forget to put anti-reflection flocking inside to avoid glare

[leanderborg220]

Don't forget to put anti-reflection flocking inside to avoid glare

will use this to paint the inside
https://www.ko-pro.black/product/musou-black-paint

[JKT]

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 diameter so that the inner tube would not contact there?

I'd also recommend using some standard adapter like M42 or T2 at the camera end. The flange mounting is pretty difficult to make even if you had the dimensions. After you decide what you use there, the next step is to think carefully just what length the two long tubes should have in order to reach your maximum and to give as small minimum as possible. That is one phase that is often assumed ... and usually then goes wrong. ;-)

[Lou Jost]

I recommend using a wider tube. This makes flocking easier and more effective, and allows you to include baffles.

[rjlittlefield]

I am curious about the motivation for custom design & build.

Why not just assemble a flocked tube from standard parts, for example as in viewtopic.php?t=35350 ?

--Rik

[Chris S.]

leanderborg220,

Enlarging on some above comments:

The various ultra-black paints seem to have durability issues, and likely do a poor job at suppressing low-angled, glancing light--which can be a large and difficult-to-trace cause of flare with tubes and couplers in macro setups. Flocking every possible internal surface of the assembly is the standard, known-good solution.

As Lou said, using a larger-diameter tube can likely permit a setup that is less prone to flare and has room for baffles, if you need them. However, most of us have not needed to do this.

Good sources of flocking are "Protostar Hi-tack flocked light trap material," and the (much-cheaper) black, velvet-like craft-store scrapbooking sheets such as "Doodlebug Beetle Black."

Like Rik, I wondered why you would machine your own tubes when very nice, ready-made tubes are available and natively interconnectable with many optical standards. In the thread Rik linked to, the Wemacro Raynox DCR 150 tube lens stands out as a good candidate for an off-the-shelf product. If you prefer to build your own--which I can well understand--consider the Thorlabs SM1, SM2, or SM3 tubes and components. (I did something similar with Edmund Optics components, back when Thorlabs' line was more limited than it is now; Thorlabs is less expensive, but still very good.)

--Chris S.

[bralex]

I am curious about the motivation for custom design & build.

Why not just assemble a flocked tube from standard parts, for example as in viewtopic.php?t=35350 ?

--Rik

I'm a hobby machinist myself - I've made a few adapters for weird thread combos. I agree with the above - seems like a lot of work for little return.

[leanderborg220]

Received the raynox 150. OO it is plastic, thought it was aluminum !