Re: First starlight for my new echelle
Posted: Sun Jun 18, 2017 8:59 am
Hi Tim, I was looking at your flat blaze plots and at one level they are as I would expect. If the flat is indeed flat across the order (which it will be more or less) then you would expect more noise to show at the peak and drop off as the attenuation from the falling efficiency kicks in. You would also expect sampling a wider aperture to smooth it out. What does the noise look like after the blaze is removed?
However, your noise is not symmetric about the peek of the blaze being stronger on the blue wing. Is this the same across all orders or just the one shown?
It made me think it could be either PRNU or possibly fringes. Another possibility is that the trace of the order is not so accurate on the blue side.
This could all irrelevant as you are getting good results and that is what counts.
Still very impressed with your work and the way you made the folding mirror. I did look at these slitshttps://lenoxlaser.com/shop/optical-apertures/standard-slits/glass-air-slit/ with the idea of getting one coated but went the fiber route in the end.
Regards Andrew
However, your noise is not symmetric about the peek of the blaze being stronger on the blue wing. Is this the same across all orders or just the one shown?
It made me think it could be either PRNU or possibly fringes. Another possibility is that the trace of the order is not so accurate on the blue side.
This could all irrelevant as you are getting good results and that is what counts.
Still very impressed with your work and the way you made the folding mirror. I did look at these slitshttps://lenoxlaser.com/shop/optical-apertures/standard-slits/glass-air-slit/ with the idea of getting one coated but went the fiber route in the end.
Regards Andrew