Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Problems with ZWO ASI071 smears and streaks

  • Please log in to reply
5 replies to this topic

#1 Christian-UAE

Christian-UAE

    Mariner 2

  • -----
  • topic starter
  • Posts: 271
  • Joined: 04 Jan 2017
  • Loc: Abu Dhabi

Posted 04 March 2017 - 01:55 AM

Hello,

I do have an ASI071 for some weeks.
Yesterday the following occurred:(I have not noticed this before but my usage of the camera was very, very limited in the last weeks)

 

When cooled down to minuses temperatures, streaks and smears starts to appear as soon as the camera sensor temperature dropped to minus degrees.

When switching off the cooler and the sensor reaches again positive Celsius temperatures, the streaks vanished.

Cooling down-they start again. the smears are not random but have always the same patterns...seems like wiping smears ??

 

This occurs whether the window dew heater is switched on or off-but I recognized there is a dew on the window from the inside.

 

 

Please see attached picture, unstretched and stretched, no filter used.

 

What can I do ?

 

Thank you very much for some hints.

 

Regards
Christian

Attached Thumbnails

  • smars1.jpg
  • smars2.jpg

Edited by Christian-UAE, 04 March 2017 - 01:56 AM.


#2 Tapio

Tapio

    Gemini

  • -----
  • Posts: 3,227
  • Joined: 24 Sep 2006
  • Loc: Tampere, Finland

Posted 04 March 2017 - 02:25 AM

That looks weird -almost like textile pattern.

Maybe changing desiccant tablets might help if that's frost.



#3 Astro829

Astro829

    Vostok 1

  • *****
  • Posts: 118
  • Joined: 06 May 2013
  • Loc: AZ

Posted 04 March 2017 - 03:20 AM

Yeah weird, looks sort of like brush strokes on canvas.

 

Try a slower cool down, i. e. instead of 5 minute use 10 for example.

 

Look for residue (because of the pattern) that maybe moisture is clinging to then freezing.

 

Dan



#4 Christian-UAE

Christian-UAE

    Mariner 2

  • -----
  • topic starter
  • Posts: 271
  • Joined: 04 Jan 2017
  • Loc: Abu Dhabi

Posted 04 March 2017 - 11:13 AM

Hi,

 

I have done some more tests and definitely when cooling, ice builds up on the sensor.

I have changed the desiccant tablets and will see what is the outcome.

During some tests with cooler just above zero, no streaks but have a look at the attached pic.

 

What is this rectangular shape ?

This is just in the center of the sensor (pic is cropped).

When strechting more, only this area is workable with, all other area outside this shape is "white"

 

 

Attached Thumbnails

  • retanle.jpg
  • retanle2.jpg

Edited by Christian-UAE, 04 March 2017 - 11:20 AM.


#5 telfish

telfish

    3D Astro Solutions, custom 3D printing for Astrophotography

  • *****
  • Vendors
  • Posts: 2,313
  • Joined: 17 Nov 2010
  • Loc: Adirondack Mountains NY

Posted 04 March 2017 - 02:54 PM

Try cooling to a lower number. I know it's counter intuitive but this camera uses residual heat from the heat sink of the TEC and routes it to the front chamber. If you cool to a higher number the heat increases and should cure this issue. You can test this out indoors. If you can get the TEC running at say 60% for a while then re test.



#6 wenjha

wenjha

    Vendor

  • *****
  • Vendors
  • Posts: 1,083
  • Joined: 24 Sep 2008
  • Loc: SuZhou China

Posted 04 March 2017 - 08:58 PM

Hi Christian

please contact us through email,sam.wen(at)zwoptical.com

seems the sensor we didnot clean very well

you may need to clean it again to solve this problem

we will tell you how to do it in email




CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics