Recently I've started to use a cooled CMOS camera (ASI533MC). At this point, the only control for the cooler feature that I've found in Ekos is turning it on and off and setting the desired temperature. But talking with friends using other software, mainly windows ones, like NINA or APT they have warned me about thermal shock induced by turning off the cooling system with the detector still at -10ºC or -15ºC.

On NINA for example, the cool down / warm up procedure ir managed using temperature and time, so you dial that you want to go to -15ºC in 5min and the software computes a gentle curve that doesn't stress the electronics. The same apply to warming up.

But I can't find nothing similar on Ekos. It seems to me that it only works on a binary ON/OFF way. What I'm missing?

Regards

This feature on the TODO list not yet implemented at INDI.

Good to know. Thanks

One way to work around this (at least for the cool down, I haven't tried to create a sequence queue for warm up) is to create a capture sequence queue that steps down through the temperatures and then does a capture at that temperature. So, for going from 20C to -10C I have a saved capture sequence queue with 7 individual sequences with a 5 minute single capture in each. First is a capture at 20C with force temperature selection at 20C. Then one at 15C etc.. down to -10C last capture only needs to be short like 1 sec. I just saved the sequence queue to a file and load it at the start of a session an reuse it. You can delete off the front or back of the queue if you want to change the range, say go 15C to -5C instead.

This way the camera is stepped down 5 degrees at a time and sits at each temperature for 5 minutes taking an image. I tag the images with a file name like 'Cool-down' so I can delete them later.

 

On my ASI533MC if I watch the power consumption in the Indi control tab for the ASI533MC I see that the camera's firmware ramps the cooling power up as it cools down.

So going from 20C to -15C the power is applied gradually - no thermal shock I would think. Now going the other way MAY be problematic, as you say there is only the OFF button.
From watching that power consumption data I see no firmware control for ramping the sensor back up to ambient. Other than the suggestion to take throw away shots at sequentially
warming temperatures, I don't see a way to have the indi-asi driver control this - perhaps ZWO could change their SDK.

Having said all that after using my ASI533MC for about six months now, almost every night (Colorado), I've seen no image problems. This might be a non-issue.

Ok it's implemented. You need latest INDI + KStars.

This is wonderful workaround. Now, I feel stupid. It's so direct. So simple. Thank you very much for the tip!

Same camera, and same experience: Cool down is with a ramp. But warmup is "free fall" I think that I will give a try to the method proposed by tunafish

Oh man, this is progressing really fast!. Thank you very much Jasem. Currenly I'm in the middle of a capture session, but tomorrow I'll try to compile the current code on the RP4 to see how it is implemented. Once again: thanks!

Is this even issue in the first place? From these topics I don't have that impression.
bbs.astronomy-imaging-camera.com/d/12096-asiair
bbs.astronomy-imaging-camera.com/d/10447-asi-1600mm-pro-cooler

I never used it myself. It's now disabled by default, so if someone wants to turn it on, they can do that.

Hi Jasem,

Sorry for the delay but compiling INDI+KStars on a raspberry is not very fast. Unfortunately as soon as the ZWO driver load it crashes. Is it posible to run the debugger on the raspberry? Thanks