Corsair thanks, having trouble running the video, won't open.
alcolmoon Oops. My bad. I didn't paste the link properly. Here it is again: https://youtu.be/nl_LQDmkg2o
Tech@ZWO trying to upload fits images but get an error OOPs something went wrong
Corsair
Hi Corsair, thanks for the link, very interesting video. Alas it didn't answer my problem, but many thanks anyway. Regards Alec
Tech@ZWO I am attaching a jpeg file to illustrate the noisy blob
the rejection-high image is the Pixinsight image after stacking the light frames, the flats image is also attached. Look forward to hearing from you.
alcolmoon Looks like the dew problem, usually caused by the high humidity inside the camera, you can redry or replace the desiccantes and cooling it slowly to try. Set the target temperature to 5 degrees and keep 5-10 minutes after it reaches, then cooling down to the temperature you want.
I will give a try firstly without trying to dry the camera tablets. I will update you afterwards. Thanks for advice A
first test completed. set target temperature at 1 deg and took 10 minutes to cool down, left to run for 10 minutes. Took 30 flats usual settings and stacked them. Result: no indication of the usual noisy area. Then cooled the camera down to -13deg left for 10 minutes and took another 30 flats. Result: the usual noisy area appeared. Job for tomorrow: dry the tablets and see what the result is. One thing that puzzles me it that if it is dampness inside the camera, why does the noisy area always appear in the same area of the image? I would have thought that the moisture would move around and the crystals, whatever they are, would form on different parts of the sensor?
Hmm. Worthwhile checking if you have oil on your sensor/lens.
https://youtu.be/3VbTEcL5qcY
https://youtu.be/tYtYR_roask
Hi folks I mistakenly reported 7 days ago that the flats taken at 1degC were Ok, further examination still showed the noisy area. I have now f ollowed the process of drying the inside of the camera. Took the 4 tablets out 2 minutes in the microwave, cleaned the sensor and put the camera cover back on, waited 48 hours for tablets to do their thing. Just took some new flats. First ones at +1degC 10 minute cool down time. Took the second set of flats at -13deg C 10 further minutes to cool down. Result, I still have this noisy area on the flats, both at 1deg and -13deg. I have attaached images to illustrate the noisy area on the flats, including the "rejection high" images produced by Pixinsight and the resultant master flat.
Any further ideas folks? Help gratefully received
alcolmoon Need to contact the seller and ship it back to us for repair.
Quick update; set the camera cooling temperature to +5degC and took new flats and lights. Calibrated the lights and stacked them. No signs of any noisy area as shown up earlier. Presumably this does not suggest a sensor fault but something freezing up on the sensor at lower temperatures??
My next step is to give the sensor a further clean and thoroughly dry the tablets in a conventional oven, rather than the microwave. Hopefully, this will put things right?
alcolmoon Redry or replace the desiccants can help
