Any ideas what this is.

[alan potts]

Along the bottom edge I have been getting a funny pattern, I thought this was icing as I have had it before though the camera was set at plus 4 C as it was 32C outside air temp, how can it be ice?

It has not been stretched at all.

Alan

[Xsubmariner]

My first thought was icing or condensation, have you tried desiccating the camera. My first generation ASI 071 used to show this type of effect.

 

[alan potts]

9 minutes ago, Xsubmariner said:

My first thought was icing or condensation, have you tried desiccating the camera. My first generation ASI 071 used to show this type of effect.

 

This is a 071 but I believe it is the 2nd gen model, it is 2 years old. It is permanently on the scope and the inside observatory temperature will be about 40C. I don't see how it could be ice as I have said but it could be condensation. I must go out and have a look see if I can see anything on the chip. Maybe I will slow down the cooldown and also try a shot before any cooling. I have only seen it for the last two weeks or so but much the same each night.

Alan 

[Xsubmariner]

  Have you tried re-drying the desiccant, if not that would be my first option. There is a link in the manual to guide the process.  Good luck with the camera, they are a great CMOS camera, mine had to be sold to help fund an IMX455 based unit.

[alan potts]

13 hours ago, Xsubmariner said:

  Have you tried re-drying the desiccant, if not that would be my first option. There is a link in the manual to guide the process.  Good luck with the camera, they are a great CMOS camera, mine had to be sold to help fund an IMX455 based unit.

No I haven't tried that as the humidity here is so low at this time of year at 30% or so. I will look into it though. It is not the first time I have had this but before I would have thought it was clearly ice. After 22 days of rain in June it was not there abut the sun has shone mainly since. Think I need to be having an in depth look at it. Only just done the flats too, more messing about once I take it off.

Alan

[ianaiken]

I'd have said Ice or condensation but the temps you've stated it cannot be ice, but maybe condensation you are quite far below ambient. What's the dew point? But, maybe it's something from your flats?

[alan potts]

On 06/08/2021 at 21:54, ianaiken said:

I'd have said Ice or condensation but the temps you've stated it cannot be ice, but maybe condensation you are quite far below ambient. What's the dew point? But, maybe it's something from your flats?

Not flats without doubt. Interesting I slowed everything down and went to 1 degree steps and actually went lower to 2C and nothing, so looks like it was condensation as you stated. Thanks for the reply. I was still about the same below ambient though as it was 28C.

Alan

[alan potts]

On 05/08/2021 at 21:30, Xsubmariner said:

  Have you tried re-drying the desiccant, if not that would be my first option. There is a link in the manual to guide the process.  Good luck with the camera, they are a great CMOS camera, mine had to be sold to help fund an IMX455 based unit.

I slowed the cooling down and it went away so looks like condensation maybe.

Thanks for the help.

Alan

[symmetal]

What might be useful Alan is to obtain one of the desiccant tubes if you can, which were included with early 1600 cameras, and maybe others. They were dropped from later camera shipments as they weren't too successful. In reality two dry desiccant tablets in the tube sharing the enclosed air with the four saturated tablets in the camera meant at best they would all end up at 66% saturation.

If the tube was left permanently attached to the camera you could change the two tablets in the tube every month or so, or before they all ended up saturated, and repeated changes should then bring the internal humidity down each time.

ASI071 cameras do have the tube access port sealed with a screw and neoprene ring, on the side of the camera under the plastic sticker, so the desiccant tube will screw on.

Maybe asking on 'Wanted' whether anyone has one they don't need may be successful. I looked on ebay, but none were advertised apart from being included with complete camera packages.

Here's the tube components and the port location on the camera. FLO do sell packs of spare tablets.

Alan

[Wiu-Wiu]

Definately ice, Alan. You have been in very hot weather so the cooler has to work overtime. I have the very same pattern (honeycomb like) in my 071 mc pro. It is not corrected by flats as it disappears after a while.  
I work around it by either cooling slower, or cool at least an hour in advance. 
Bummer for when going out on location because I lose an hour of battery time that way. 

 

 

I’ve never seen anyone open up my 071 on the side, you might want to double or triple check the exact type! I open it up from the top (double plated) and the dessicant tabs are in the top next to the sensor.

Edited August 8, 2021 by Wiu-Wiu

[alan potts]

On 08/08/2021 at 23:22, Wiu-Wiu said:

Definately ice, Alan. You have been in very hot weather so the cooler has to work overtime. I have the very same pattern (honeycomb like) in my 071 mc pro. It is not corrected by flats as it disappears after a while.  
I work around it by either cooling slower, or cool at least an hour in advance. 
Bummer for when going out on location because I lose an hour of battery time that way. 

 

 

I’ve never seen anyone open up my 071 on the side, you might want to double or triple check the exact type! I open it up from the top (double plated) and the dessicant tabs are in the top next to the sensor.

Hi Dave,

Yes it has been hot but according to data the cooler was never working above 50% and the set temperature was not at zero, it was in fact 4C. I would have though ice was not possible if that figure is accurate. I have though got the exact same affect that you show on a number of occasions. I does seem to have gone away now as I slowed down the cooling, then other nights never saw it as I may well have cooled about an hour in front of the first exposure.

Alan