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Could it be frost/dew on sensor?

Posted: Thu Jan 30, 2020 3:11 am
by javrolijk
Hi all,

I was hoping someone might provide some thoughts on an issue I'm having with my images. I did a two-night session on the Jellyfish nebula but the center of the Integration seems to be overly dark compared to other areas. I've noticed it's also a little on other images as well. I used AstroPixelProcessor (APP) to calibrate the frames and noticed the NormalizationMap and RejectionMap also contains this pattern. There's just something going on in the middle. Could it be something going on with the camera e.g. frost?

Attached is the RejectionMap and Integration out of AstroPixelProcessor (APP).

Equipment used:
OTA: Explore Scientific 102mm f/7 Triplet ED APO Refractor
Cameras: ZWO ASI294MC Pro
Filter: Optolong L-eNhance
Cooled to -10 degrees C.

Many thanks in advance for any thoughts.
Jairo
Integration.jpg
RejectionMap.jpg

Re: Could it be frost/dew on sensor?

Posted: Thu Feb 06, 2020 3:45 pm
by Katherine.Tsai
Does it show when the camera cooling is not turned on?
Please take two flats,one with cooling and one without cooling, then share this two flats to us via Google Drive or Dropbox.
I would like to take a further look at this.

Re: Could it be frost/dew on sensor?

Posted: Tue Feb 11, 2020 5:35 am
by javrolijk
Katherine.Tsai wrote:
Thu Feb 06, 2020 3:45 pm
Does it show when the camera cooling is not turned on?
Please take two flats,one with cooling and one without cooling, then share this two flats to us via Google Drive or Dropbox.
I would like to take a further look at this.
Hi Katherine,

I've got a chance to take the flats. Below is a link with two folders which consists of 5 Flats frames taken at -10°C at 120 Gain with a white t-shirt. And the other folder has 5 Flat frames taken at ambient temp (about 24°C) at 120 Gain.

I did notice that the pattern disappeared when the temperature was about 2-3°C. Your input is highly appreciated.
Link to Flat frames: https://drive.google.com/drive/folders/ ... sp=sharing

Kind regards,

Jairo

Re: Could it be frost/dew on sensor?

Posted: Tue Feb 11, 2020 9:27 am
by Katherine.Tsai
Hi Jairo,
I am sorry to tell you the camera need to be sent back for repair.
If you buy it directly from us,
Please send an email to support@zwoptical.com and add a note: ZWO's Katherine checked, sensor getting dew.
If you buy it from a dealer, please contact the dealer.

Re: Could it be frost/dew on sensor?

Posted: Tue Feb 11, 2020 11:10 am
by javrolijk
Katherine.Tsai wrote:
Tue Feb 11, 2020 9:27 am
Hi Jairo,
I am sorry to tell you the camera need to be sent back for repair.
If you buy it directly from us,
Please send an email to support@zwoptical.com and add a note: ZWO's Katherine checked, sensor getting dew.
If you buy it from a dealer, please contact the dealer.
Hi Katherine,

What should I say to the dealer? In this case it was OPTCorp in the U.S.
May I ask what seems to be the issue with the camera/sensor? Would a replacement of the desiccant tabs help?

Kind regards,

Jairo

Re: Could it be frost/dew on sensor?

Posted: Wed Feb 12, 2020 9:40 am
by Katherine.Tsai
javrolijk wrote:
Tue Feb 11, 2020 11:10 am
Katherine.Tsai wrote:
Tue Feb 11, 2020 9:27 am
Hi Jairo,
I am sorry to tell you the camera need to be sent back for repair.
If you buy it directly from us,
Please send an email to support@zwoptical.com and add a note: ZWO's Katherine checked, sensor getting dew.
If you buy it from a dealer, please contact the dealer.
Hi Katherine,

What should I say to the dealer? In this case it was OPTCorp in the U.S.
May I ask what seems to be the issue with the camera/sensor? Would a replacement of the desiccant tabs help?

Kind regards,

Jairo
You can add attach this link to your email and add this note:
ZWO's Katherine checked, sensor getting dew.