ZWO ASI290MM, dirt on sensor.

[Bill Hume]

Hi, I use my ZWO ASI290MM for solar with my Coronado 50 PST. It works well but I can never keep the sensor clean. I'm quite capable of cleaning it (I regularly clean the sensor on my DSLR). Thing is, I clean it then the next time I use it, there are more dirt specs visible. I just don't know where they are coming from. Has anyone else experienced this problem and if so, do you have a solution.
Bill H.

[Gordon]

I've had similar problems with my Daystar Quark. It appears it might be outgassing within the sensor area. This gives the 'spots' a 'greasy' look. Since the Quark is not supposed to be opened I just take flats by defocusing and that seems to fix the problem.

[Bill Hume]

I've had similar problems with my Daystar Quark. It appears it might be outgassing within the sensor area. This gives the 'spots' a 'greasy' look. Since the Quark is not supposed to be opened I just take flats by defocusing and that seems to fix the problem.

Thank you Gordon. I've never tried using flats for solar. I'll give it a go.
Bill H.