Uvex build log

Uvex build log

Postby Thibault N » Thu Jan 16, 2020 1:04 pm

Dear all,

I would like to start a thread to log my (along with 2 friends that were at the 2019 spectro star party) efforts to build 3 uvex spectroscopes in a row. The base document I am using is this one: http://www.astrosurf.com/buil/UVEX_project/ and I might use also http://uvex30.000webhostapp.com/calibrex-par-lopex/ later on for calibration (but I might decide to use the readymade Shelyak Neon Argon system + spox for automation).

Regarding the precision parts from Thorlabs, my cart is already full, but I haven't ordered the parts yet, for interested people, here are the references:
ThorLabs.png (57.42 KiB) Viewed 1878 times

As csv (xls are not allowed there):
Produit,Description,Product URL,Quantité,Prix,Sous-Total,Currency
GR25-0305,Ruled Reflective Diffraction Grating 300/mm 500 nm Blaze 25 x 25 x 6 mm,https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=8626,1,106.23,106.23,Euro
CM254-100-G01,"Ø1"" Aluminum-Coated Concave Mirror f = 100.0 mm",https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=1161,2,54.85,109.7,Euro
FMP1/M,"Fixed Ø1"" Mirror Mount M4 Tap",https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=989,2,15.54,31.08,Euro
LJ1934L1-A,f = 150.00 mm H = 20.00 mm L = 22.0 mm N-BK7 Plano-Convex Cylindrical Lens Antireflection Coating: 350-700 nm,https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=2797,1,87.55,87.55,Euro

I also ordered Kapton-like tape in order to secure the lens from https://www.amazon.fr/gp/product/B073CW9Z3K/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1:

And 3 pass taps for M3 and M4 screws: https://www.manomano.fr/p/tarauds-hss-3-passes-jeu-de-3-tarauds-2988654?product_id=3035169 and https://www.manomano.fr/p/tarauds-hss-3-passes-jeu-de-3-tarauds-2988654?product_id=3035170:
tarauds.jpg (23.11 KiB) Viewed 1878 times

Now, I also started to print all parts 3 times with a fdm printer, using black petg from sunlu (more pictures to come).
Thibault N
Posts: 18
Joined: Mon Aug 05, 2019 2:42 pm

Re: Uvex build log

Postby James Foster » Wed Jan 22, 2020 5:45 pm

I'm interested in the UVEX3 myself and have partially prepared by buying a Atik414ex CCD and this product from Thorlabs:
WG41010 Ø1" UVFS Broadband Precision Window, Uncoated, t = 1 mm

I also purchased a spanner that makes changing the old Atik414ex cover glass with this new UV transparent glass a snap; let me know if you
need the part number for this as well.

I can easily go down to 3600A with the Alpy600 with this sensor set-up; see Aply600&Atik414ex + LISA-IR:
However the UVEX3 will be more powerful by being a purely reflective system. Because I tuned my Alpy600 to get sharp UV/Blue response, my red around H-Alpha suffers.

James Foster
Lhires III (2400/1800/600 ln/mm Grat) Spectroscope,
LISA IR/Visual Spectroscope (IR Configured Presently)
Alpy 600 with Guide/Calibration modules and Photometric slit
Star Analyzer 200
James Foster
Posts: 404
Joined: Sun Jan 24, 2016 7:14 am

Re: Uvex build log

Postby Thibault N » Thu Jan 23, 2020 10:56 am

Very interesting James Foster thank you for the feedback.
I am most likely going to buy a CMOS sensor, because I'd like to experiment with it and it is going to be the future anyway. However, I haven't chosen the sensor yet.
I am waiting for availability of a mono BSI sensor with QE>80%/85% and >60% in the UV preferably without amp glow.

For now, the only cmos sensors that features that kind of characteristics are either out of my price range (Gsense 2020) or colour sensor (imx533), but I hope to see something new this year that would feat the requirements. Otherwise, I'll probably buy an IMX183.

One of the possible issue I see with the Uvex are those:
- It features a lens inside to correct for optical aberration, hence it is not fully reflective and might suffer a bit from chromatism (but I guess the result are much better with the lens than without)

-It is not really a problem, but I'll probably try to use a low res diffraction grating (maybe 200 ? or even 150 ?) and very thin slit (10 microns ?) in order to exploit small pixels of the cmos. However, as the UVEX optics are optimized for f/8 scope, I'll probably loose a lot of light in the process, I guess >8" f/8 scopes have a fwhm much larger than 10 microns.

-Shelyak (Ar/Ne) calibration system looks really neat, unfortunately it would be much better with (Hg Ar) lamps in order to calibrate in UV.

I do not exclude the possibility to buy an Alpy anyway
Thibault N
Posts: 18
Joined: Mon Aug 05, 2019 2:42 pm

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