Not sure what this is

[sinbad40]

Hi all

So tonight set everything up, but the images looked like it was a submarine periscope look from a film. But light on the outside dark in middle.  Thought it was me not putting the dew heater on.  Went out with a 12v hair dryer gave it a blast, checked dew heater and it was on.  Came back in to check the image after doing other things for 15  mins and all seemed fine. Started the session.

Couple of hours later it is happening again.  So stopped, moved the scope to have a look at the front as dew strap is still on, can't see any dew, but gave it a quick blast with the 12v hair dryer again, but still the same.

Dew heater on camera is showing as on, moved the filter to empty. Still the same.

Not had this before, and it was a clear night as well

 

 

 

Edited September 3, 2023 by sinbad40

[Graham Darke]

Were you using a cooled camera? 

[ollypenrice]

Possible dew - or ice - on the chip window.  The source must be fairly close the the chip since an obstruction at the front of the tube would be blurred out of visibility, as is a secondary mirror, for instance.

Olly

[tomato]

It does look like moisture on the camera sensor window to me. If you can remove the camera you will be able to see it for confirmation. 
I’m not sure why you are getting this if you have a functioning heater on the camera, though.

[Tomatobro]

https://www.altairastro.help/info-instructions/faq/how-do-i-stop-dew-moisture-forming-on-the-outside-of-my-tec-camera-optical-window/

[sinbad40]

Thanks all, (only just woken up).  I managed to get it back by turning the cooling off, it cleared in seconds, and then seemed fine, as light broke

Read the link Tomatobro, looks like i was lucky with what i did, just thought i had an issue with the camera as not had it before.

Thanks all for the replies, and fingers crossed for tonight,

[adyj1]

Just for background, what camera is it? What software are you using to turn it on and off? 

[sinbad40]

5 hours ago, adyj1 said:

Just for background, what camera is it? What software are you using to turn it on and off? 

Its an Altair 533 ctec hypercam, using nina, as i say, not had the issue before.  Tonight, I will take the cooling down slowly with heater on full pelt, only down to -10

Edited September 3, 2023 by sinbad40

[adyj1]

17 hours ago, sinbad40 said:

Its an Altair 533 ctec hypercam, using nina, as i say, not had the issue before.  Tonight, I will take the cooling down slowly with heater on full pelt, only down to -10

The reason I ask is I have recently acquired a 183c which the Altair specs say has a heater built in. In NINA, no heater control is shown in the 'camera' panel of the Equipment tag and I was getting much the same result as you (see pic). 

I fitted the zwo heater strip and run a couple of all-night tests and it seems to have fixed it... 

I guess my camera doesn't have a built-in heater 😔 

(cooled to -5 over 2 mins in NINA)

Edited September 4, 2023 by adyj1
reduce picture size

[Clarkey]

6 hours ago, adyj1 said:

I guess my camera doesn't have a built-in heater 😔 

I think the built-in heaters are fairly poor. I have a built-in heater on my IMX571 (RisingCam) and this always had dew even when it was on. I did the same as you and added the extra ZWO heater. No issues since.

It was exceptionally humid last night.

Edited September 4, 2023 by Clarkey

[sinbad40]

It was another humid night, but no issues last night.  Turned the heater on first, then after 10 mins, dropped the cooling down by 2 every 10 mins to get it to -10 as it was getting dark, all fine, apart form the cloud   If it happens again, I may invest in the extra heater.

[sinbad40]

Well, extra ZWO heater ordered after it happened twice more, so that should be sorted when fitted.