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Alpy600 fine tuning

Posted: Sat Aug 30, 2014 1:36 pm
by Miguel Rodriguez
Hello all,
I'm trying to achieve the best resolution available with my Alpy600. For doing this, I'm checking the focus of the slit. When I think I have a good focus I perform some images of solar spectrum, together with calibration spectrum, offset, dark and flats, and then I process spectrum and look for resolving power value. The best value I can achieve is a bit more than 500. Very small adjustments inside and outside focus doesn't get a better resolution.

¿Am I following a good tuning procedure? ¿What is your fine tuning method on your Alpy600?

Regards
Miguel

Re: Alpy600 fine tuning

Posted: Sat Aug 30, 2014 4:46 pm
by Peter Somogyi
Doing exactly the same, having only ~500 resolution too (via Alpy cal.lamp + ISIS v5.4.1 wizard giving this value).
All I can achieve is having better average focus on a wider field (edge areas still blurred - that got focused only when middle is out of focus...).
Using a Landlite 15W "A class" energy saving lamp.
I can turn the core element +-45 degree angle but don't see visually any difference to my old setup (with ~500 res.) - except the up & down borders less blurred.
Interested in the same problem.

Re: Alpy600 fine tuning

Posted: Wed Sep 03, 2014 12:16 am
by Christian Buil
Sun and artificial lamps are excellent sources for adjust the focus. A R = 500 is a very correct value for Alpy 600 (23 microns slit width I suppose).

Christian

Re: Alpy600 fine tuning

Posted: Wed Sep 03, 2014 11:51 am
by Miguel Rodriguez
Thanks for your comments, Christian. Yes, my slit is 23micron. Good to know I get a correct value.
The first time I tried a fine tuning I used an A star spectrum, and finally got a worse result than before. This time, with Ne lamp spectrum and solar spectrum I achieve R=523.