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Review of the Solutions to Newtons Rings in Solar Imaging

Posted: Tue Dec 27, 2016 12:18 pm
by marktownley
Hi All,

Please find my review of the commercial solutions you can adopt to get rid of newtons rings when solar imaging. It is on my website, so please click the link:

https://brierleyhillsolar.blogspot.co.u ... rings.html

Thanks

Mark

Re: Review of the Solutions to Newtons Rings in Solar Imaging

Posted: Wed Dec 28, 2016 5:19 am
by pstew
Thanks Mark

Re: Review of the Solutions to Newtons Rings in Solar Imaging

Posted: Thu Jan 05, 2017 3:21 am
by Okay-1
Good overview Mark.

Re: Review of the Solutions to Newtons Rings in Solar Imaging

Posted: Wed Sep 20, 2017 7:02 pm
by Bruce Girrell
Thank you Mark. Very helpful information

This effect has puzzled me since I started looking for an astro camera. Does anyone have a good explanation for it yet? The "Newton's rings" name had me confused for a while until I realized that it simply looks like Newton's rings and that no one was claiming that as a description of the physics involved. My guess is that the effect is related to the thickness of the oxide layer in CMOS fabrication. This thickness varies with the foundry making the chips and the application for which the chip is intended, but the oxide thickness values I have seen range between 1/4 wavelength to a full wavelength at 656 nm. Because the oxide thickness is close to the wavelength of light that we're using and we use such a very narrow frequency band, there exists opportunity to set up something of a beat frequency between the incoming light and the reflections within the oxide layer. This effect would seem likely to be exacerbated by the use of a rolling shutter on the camera.

So far, I have observed the effect in only one portion of my image (the center, of course) and I have really observed it only once (which, interestingly, was just after I had cleaned the glass in front of my image sensor - I had never seen the effect up that point). By the time I finalized adjustments of the image, the effect was no longer visible. Maybe I'm one of the lucky ones.

I suppose I should hope that I don't get more chances to study the phenomenon, but I have a feeling that I will. If so, I may have to check back here and try out one or more of your solutions. Thanks again

Re: Review of the Solutions to Newtons Rings in Solar Imaging

Posted: Thu Dec 14, 2017 6:13 pm
by PlanilAstro
Thank you Mark for the great article.

Re: Review of the Solutions to Newtons Rings in Solar Imaging

Posted: Thu Dec 14, 2017 6:28 pm
by marktownley
Thanks all.