CharlieM
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Posts posted by CharlieM
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1 hour ago, robin_astro said:
lenses which have many elements to correct for various aberrations, important for making good sharp images across the field at low focal ratios rather than specifically for spectroscopy. You can use simpler (smaller and lighter) achromats in spectrographs eg the StarEx, LowSpec, LHIRES all use achromats but they do have drawbacks such as not working well at low focal ratios and suffer from chromatic aberration, particularly noticeable as a shift of focus at the blue end of the spectrum.
Ok. I take that to mean aberrations caused by the spec itself and not the scope. I'm using an RC8. I'm a little confused as to which design to settle on now. If a single lens is going to be so much of a problem, perhaps I need to look at the UVEX as opposed to the StarEx, which was my plan forward ??
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On 12/10/2019 at 12:13, robin_astro said:
Hi Louise,
Christian Buil has a nice page which goes through the design of a classical spectrograph here
http://www.astrosurf.com/buil/us/stage/calcul/design_us.htm
Cheers
Robin
I hope you don't mind the newbie questions but I notice on that page that Christian is using a lot more lenses than i have seen in the DIY designs like the Starex. Is there a reason , for example, that he uses a single achromat for a collimator in the Starex, but numerous lenses on that page ? Was it just a matter of convenience ?
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On 01/11/2019 at 08:03, Thalestris24 said:
Hi all
Has anyone had any dealings with Ovio Optics? They are a French company. I've been trying to place an order with them for a reflective spectrometer slit but I just can't get it to checkout! They seem to have a convoluted order processing procedure especially for any order outside France. As far as I can tell I've done all that's required - agreed their terms, requested a shipping estimate, selected a payment method. I get an estimate and click on 'convert to cart' but end up going round in circles! It just keeps leaving out the shipping details. I've emailed them - they have a separate email for exports. But no reply. Very frustrating! If anyone on here has used them and know the magic word, I'd love to have it!
Louise
I'm clicking the links in this thread and getting nowhere. Louise, did you finally get your plate and if so, can you please tell me, with a link that works, where you got it from ? Thank you.
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On 24/01/2018 at 15:47, Merlin66 said:
I designed the original OVIO multi-slit plate for the Spectra-L200.
Yes, with a suitable transfer lens and the slit inclined at 15 deg you see the 6mm long slit gap and the reference number.
Check out our website for more info. http://www.astronomicalspectroscopy.com/instrument.html
I'd love to know how these plates are slotted with such precision. Lasers ? Photo etching ?
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Happy I found this and sorry I'm late to the thread. Pity as I could have run off some of these mechanical components in my machine shop and sent them out for the cost of shipping. I have just printed the main body and lid of the Lowspec. I'd love to hear from anyone else who has built it. This thread ends short of a final successful build and performance review. This DIY might be worthy of its own category or website/FB page ?
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Did this ever get done ? The OP was supposed to post a solution, as is very helpful to others with the same problem.
UVEX3
in Radio Astronomy and Spectroscopy
Posted
I lost track of Tony Rodda. He , as I understood it, was going to send me his modded files for the Starex cause I did buy Ken's Ovio slit wheel and don't want it to go to waste. I was going to make Paul's LowSpec but changed my mind. I guess I'm on hold until I hear from Tony. I hope he hasn't forgotten me. If I could find editable versions of the StarEx, I might just do my own mods for the StarEx.