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CMOS photometry/astrometry

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#1 Justin Fuller

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Posted 24 February 2020 - 02:19 PM

I'm wondering, has anyone here successfully done high precision photometry and or astrometry with something as cheap as a ZWO mono AS120? To me, in theory, it seems that with good quality Johnson UVBRI filters and a good calibration routine, it should be possible to do good photometry, and astrometry...but I haven't been able to find if anyone has gotten acceptable results using such a cheap camera. Thanks in advance for your insight.

Not sure if this is the appropriate forum, feel free to move if necessary.

#2 dhkaiser



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Posted 24 February 2020 - 05:33 PM

See https://www.aavso.or...hotometry-setup

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#3 Exciton


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Posted 25 February 2020 - 02:50 PM



Using CMOS cameras for photometry is a popular topic in the AAVSO forums, you might check it out at https://www.aavso.or...eras-photometry .  Given the appropriate characterization and calibration of your ZWO camera, there is no reason why you should not be able to make effective photometry measurements. 


I recently took the AAVSO beginner class in photometry and had a great time learning photometry with like-minded individuals who want to use their astronomy rigs to contribute a little science (many classes are available https://www.aavso.or...020-non-members ). 



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#4 glmorri



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Posted 26 January 2021 - 11:22 AM



I've had good luck with a ASI 120:


CMOS astrometry of double stars on the island of Kauai, Hawaiian Islands (Grant Morris)


found in DSSC 28





#5 garyhawkins



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Posted 07 February 2021 - 11:56 PM

What do you call precision?  I believe with my setup of a C8 SCT/F6.3 Focal Reducer/ZWO ASI533MC, one percent relative flux changes are usefully measured.  

#6 Ed Wiley

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Posted 09 February 2021 - 11:36 PM

Photometry is best done with cooled cameras. I assume by "precision" you mean accurate. Also, you have to watch your FOV, so match to available scope is a important consideration. Why? You need a large-enough FOV to catch suitable comp stars as well as the variable. But theoretically? Sure I suspect under the right conditions you could do some reasonable photometry with the little 120. Its just another CMOS camera. In fact, I bet its already been done.




ps: Ken Menzies and I did an accuracy/precision study using both CCD and CMOS cameras. No problem with cooled CMOS cameras for photometry and reasonable accuracy of 0.02 magnitude is the usually level of accuracy with the amateur-level equipment we had and the techniques used. See the talk that starts about 44 minutes into this  AAVSO You Tube video:




I'm working on the manuscript now.

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