Thorlabs SM2 tubes flocking? (+ other question)

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nielsgeode
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Thorlabs SM2 tubes flocking? (+ other question)

Post by nielsgeode »

My new Thorlabs SM2-based setup(s) are (finally) getting finished. Stacking is not my primary goal and instead my setup is a tool to take good and beautiful pictures of the specimens of my mineral collection. For around 1x mag. I use an 8000ED scanner lens. For 2x I have a Dimage 5400 lens. For 4x I use a Nikon Plan Apo 4x NA 0.20 and for 5x and above I use Mitutoyo objectives.

For anything under 1x I can use my Zeiss 100mm macro. However, it's not ideal because I cannot mount that lens as it has no tripod collar. So I'm considering
a) have a custom tripod collar made. I'm a bit worried about my lens because dimensions are critical and I don't want to clamp it in too tight and damage My Zeiss lens.
b) find a different solution with similar image quality and a magnification range of about 0.2x - 0.7x
c) something else? Let me know please.


Then I wonder how much of a difference it will make if you flock the SM2 tubes. Sometimes I have the feeling contrast is already good and sometimes I have the feeling things look like there is too much flare inside the tubes. If you have experience, please let me know.

PS Once this is done I will start taking beautiful pictures and post them on the forum :D

JKT
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Re: Thorlabs SM2 tubes flocking? (+ other question)

Post by JKT »

As far as damaging the lens goes, it is relatively difficult to damage round metal tube with distributed compression. Sharp ridges are to be avoided, though. The diameter of the clamp is also important. If it is off, you could indeed damage the lens.

It is also possible to dimension the clamp so that there will be some intermediate layer between lens and clamp. Very thin rubber or chamois should work well. However, then the clamping surface should be long enough to minimize rotation around clamp center.

chris_ma
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Re: Thorlabs SM2 tubes flocking? (+ other question)

Post by chris_ma »

if you want variable macro in the 0.2 to 0.7 range then a lens with native mount and focus mechanism is certainly more convenient then a thorlabs setup where you have to add spacer rings every time you want to change magnification.

personally I'd just get a tripod collar slightly bigger and use a rubber spacer to get a tight fit.

but if you don't plan to do stacking, couldn't you just mount the camera directly?
chris

nielsgeode
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Re: Thorlabs SM2 tubes flocking? (+ other question)

Post by nielsgeode »

chris_ma wrote:
Sun Oct 25, 2020 4:01 pm
if you want variable macro in the 0.2 to 0.7 range then a lens with native mount and focus mechanism is certainly more convenient then a thorlabs setup where you have to add spacer rings every time you want to change magnification.

personally I'd just get a tripod collar slightly bigger and use a rubber spacer to get a tight fit.

but if you don't plan to do stacking, couldn't you just mount the camera directly?
Yes, I do plan to do stacking. The specimens are between 5 and 15 centimeter, so at f/8 there is not enough DoF to get everything in focus. That's why I like to use my vertical stacking setup that has the SuperNova LED light from the German company Stonemaster.

In many cases I use a short EF extension tube with the Zeiss 100 macro because it's maximum 'native' magnification is only 0.5x. I wonder if there are EF tubes (with or without electronics) that the option to add a collar that fits. I did a (quick) search, but haven't been able to find something. It seems almost nobody is using collars for their macro lenses / setup...

dgarnick
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Re: Thorlabs SM2 tubes flocking? (+ other question)

Post by dgarnick »

Regarding flocking:

I just put together a setup with Thorlabs SM2 tubes, a Nikon 10x infinity objective and a reversed Raynox 150. My first shots had very bad flare and concentric halos. I flocked the tubes, and the back of the objective adapter, with craft store stick on felt. The improvement was significant, but there is still a noticeable halo.

I've learned from telescope forums that Protostar's Flockboard and Hi-Tack Flock sheets are rated highly. The Flockboard is semi-rigid; cut it to size, roll it, put it in the tube, and let it pop open; no adhesive is needed. The Hi-Tack is adhesive backed material.

Here's testing showing the reflectivity of different flocking materials, including Protostar's:
https://www.cloudynights.com/articles/c ... uction-r82

And here are the Protostar products:
https://www.fpi-protostar.com/flockboard.htm
https://www.fpi-protostar.com/hitack.htm

Be wary of my advice, I'm a total beginner with photomacrography!

- David

rjlittlefield
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Re: Thorlabs SM2 tubes flocking? (+ other question)

Post by rjlittlefield »

dgarnick wrote:
Mon Nov 30, 2020 12:05 pm
I just put together a setup with Thorlabs SM2 tubes, a Nikon 10x infinity objective and a reversed Raynox 150. My first shots had very bad flare and concentric halos. I flocked the tubes, and the back of the objective adapter, with craft store stick on felt. The improvement was significant, but there is still a noticeable halo.
For some other ideas of what problems to look for, and how to look for them, see https://www.photomacrography.net/forum/ ... hp?t=35350 .

Note in particular that you may need to flock the inside of the bayonet adapter that fits into the camera body.

As for best material, I use Doodlebug Beetle Black Crushed Velvet Scrapbook Paper, for example HERE at Hobby Lobby. It tests as substantially blacker than Protostar, probably more like the "Deluxe Black Velvet" shown at "limit of test equip" in the graph that you link to. My test is at https://www.photomacrography.net/forum/ ... hp?t=17917 . For telescope use, the Doodlebug product has the big disadvantage that it is not available in large sheets for flocking large tubes. But for small tubes, I find that the Doodlebug is much easier to work with than either of the Protostar products.

--Rik

dgarnick
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Re: Thorlabs SM2 tubes flocking? (+ other question)

Post by dgarnick »

Great information. Thanks! I'll try the Doodlebug velvet.
David Garnick

RobertOToole
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Re: Thorlabs SM2 tubes flocking? (+ other question)

Post by RobertOToole »

nielsgeode wrote:
Sun Oct 25, 2020 10:38 am
My new Thorlabs SM2-based setup(s) are (finally) getting finished. Stacking is not my primary goal and instead my setup is a tool to take good and beautiful pictures of the specimens of my mineral collection. For around 1x mag. I use an 8000ED scanner lens. For 2x I have a Dimage 5400 lens. For 4x I use a Nikon Plan Apo 4x NA 0.20 and for 5x and above I use Mitutoyo objectives.

For anything under 1x I can use my Zeiss 100mm macro. However, it's not ideal because I cannot mount that lens as it has no tripod collar. So I'm considering
a) have a custom tripod collar made. I'm a bit worried about my lens because dimensions are critical and I don't want to clamp it in too tight and damage My Zeiss lens.
b) find a different solution with similar image quality and a magnification range of about 0.2x - 0.7x
c) something else? Let me know please.


Then I wonder how much of a difference it will make if you flock the SM2 tubes. Sometimes I have the feeling contrast is already good and sometimes I have the feeling things look like there is too much flare inside the tubes. If you have experience, please let me know.

PS Once this is done I will start taking beautiful pictures and post them on the forum :D
Each and every time I use SM2 tubes I use flocking material. I find that on some lenses it does not make much difference in contrast if I forget to add it, but some lenses suffer with lower contrast. So now I just flock each time at setup.

I actually use matte suede black paper bought in 8.5 x 11 sheets cut to size. I still have a giant roll of flocking adhesive backed tape in my storage cabinet if you need some.

Best,

Robert

Jmurphy18
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Re: Thorlabs SM2 tubes flocking? (+ other question)

Post by Jmurphy18 »

Just an FYI on the Doodlebug Beetle Black Crushed Velvet Scrapbook Paper. Scrapbook.com has the paper cheaper including shipping
Thanks for the info folks
JohnM

dgarnick
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Re: Thorlabs SM2 tubes flocking? (+ other question)

Post by dgarnick »

Jmurphy18 wrote:
Mon Jun 14, 2021 3:03 pm
Just an FYI on the Doodlebug Beetle Black Crushed Velvet Scrapbook Paper. Scrapbook.com has the paper cheaper including shipping
Thanks for the info folks
Thanks for the source, John. The Doodlebug Beetle Black gave me the best results. I use a black sharpie to darken the white edges of pieces. I still use the ProtoStar Hi-Tack where adhesion is important - on the back of the tube-to-objective adapter, and on the inside of the bayonet adapter.

Also, I now use the Doodlebug sheets to create pure black backgrounds. I find it cuts down on a bit of haziness I sometimes get from light reflecting off the background into the lens.
David Garnick

Jmurphy18
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Re: Thorlabs SM2 tubes flocking? (+ other question)

Post by Jmurphy18 »

Thanks for the tip David! My order came today so I intend to flock my tubes tomorrow
JohnM

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