3D printed spectroscope inspired by Dmitry and others

[jscff]

Hi everybody,

 

I just wanted to share my little solution for using the ubiquitous cheap jeweler spectroscope to aquire spectroscopic images. Alignment is fairly nice and it can be screwed onto lenses. It also allows for filters to be placed infront of the spectroscope to facilitate comparisons. If step-up or step-down rings will be used, focus can be aquired by moving the spectroscope in and out of the rear part of the adapter. Attached you can find some pictures of the adapter and two example pictures using the Ennalyt 35 f3.5 on a full-spectrum X-E1. All images are out of cam.

 

The first spectrum is the sunlight, the second is the sunlight with a new KolariVision UV-Passfilter in front of the lens.

To illustratrate that one can aquire well focused images, I also attached another spectrum. Sunlight with correct focus (lens set to 0.8m, and spectroscope moved). I think I can clearly see Fraunhofer lines.

 

Using tinkercad I drew up a simple model consisting of two parts. I attached the STL files to this post.

 

The base part is 24mm tall and 60mm wide. There is a recess which holds a 52mm filterring. In the middle is the hole for the spectroscope. The canal is faily long to secure alignment.

The front part is 12mm tall and 60mm wide, it also has a central canal and a recess which holds a 52mm filter ring.

 

 

Parts needed:

1 x Jeweller spectroscope (outer diameter 13.95 mm)

2 x 52mm filter-rings (the ones I use measure 53.93 to 54 mm outer diameter)

Black Felt

3D Printer (I used PLA and a cheap Monoprice Delta Mini V2 with Ultimaker Cura 4.3)

About 6 hours print time (heavily depending on layer height and infill)

 

 

 

Kind regards,

Jonathan

 

 

 

ps: If you have any questions or recommendations for improvement, please let me know. I might be a bit slow to answer, but I am happy for feedback.

pps: Yes, it seems I have dust under the glass-cover of my sensor. :(

ppps: before I bought the jeweller spectroscope used by Dmitry I bought a more expensive Krüss 1501. But I was disappointed. It does not show UV or IR light, only VIS.

China Spectroskop to 52mm Adapter Front.stl China Spectroskop to 52mm Adapter Back.stl

[Nate]

That looks great. I wish I had a 3D printer. I came up with this recently. I need to hold it on the lens until I figure something out, but works pretty good for visual wavelengths, but the higher and lower ends are cut off. I found moving the spectroscope to the each side works a little.

[Dmitry]

Interesting idea about filter holder!

You can add more nested layers to screw filters of other size.

[Kai]

Do you know anything about the UV transmittance of the prisms?
The picture taken through the UV filter looks very promising.
In any case, a good project!
Thank you for sharing, Jonathan :)

[Chris Culpepper]

Jscff, are you able to see both UV and IR at the same time with your spectroscope/lens combo? I can't see both with out rotating the spectroscope a little bit. I'm going to try cutting a little of the eyepiece cone to see if more spectrum can be seen.

[jscff]

@Nate Well I did not have a 3D Printer either when this year begun. I paid about 120 $ for mine, with enough black PLA for all my adapter projects. I bought the printer to print small round adapters for macro-lenses (if you do stage-based focus stacking alignment is not that critical). I never used a CAD software before, but Tinkercard was so easy, after one youtube tutorial I got the hang of it. I think designing a ring that holds your spectroscope in place would take 10 minutes, counting measuring in. You could design it of centered, so turning it inside your Astro-Tube would reveal more of the spectrum.

 

@Dmitry Thank you for your input! The idea of nesting adapters instead of using step up rings seems nice, as it would reduce the amount of air between the filters.

 

@KaiI do not know much about the transmittance - only that I can see much more UV with this spectoscope than with the one from Krüss (which showed no UV at all). I think it should go down to 365 nm or otherwise I would see less of a band? Once I will succeed doing a pinhole and grating spectroscope I may be able to compare them a bit.

But @Dmitry has been using the exact same thing for his tests, so I think it should suffice at least for my current project goal (wet plate colloidon emulation).

 

@Chris Culpepper I have not yet watched out for IR using a IR Filter at the front, but I think the second spectrum shows that one can see UV and the IR bleed in one image. I will check it in the next days and report back.

[Dmitry]

334nm is possible, test is here