Matching darks to deal with "amp glow"

It's not recommended to use the cooler at 100% power. If your camera isn't able to get to -20, why not set it at -15 and just take a new set of darks? That's part of the beauty of a regulated, cooled camera. It's really easy to take your darks and match them to your lights.

Similarly here I run my asi183mm between -10C and -15C… whichever keeps me under around 80% power on a night. I'll usually drop it down to cooler later in the session, but use two different masters for each target temperature as a 5C difference does tend to not get all of the amp glow for me.

Why don't you just use -10 for everything?

Topic is old, but just to tell my experience with 183M (mine a QHY). It is a great camera, but the amp glow is really the weak aspect of it. That being said, it is smtg that can be removed with correct dark frames.
Initially I had my dark frames generated during day time. The target temperature (-15 C) was reached, but using more power than at night, as the ambient temperature during day is higher. I was having difficulties to remove the amp glow with the darks generated in this circumstance.
My problem disappeared when I generated the darks at night, in an ambient temperature similar to the lights, and consequently a similar power consumption.
And no, I didnt have any light leak during day generation of the darks.
It is not that amb temp must be very similar, probably it still Okey < 10 degrees difference. But take care to not generate dark and lights with too much  difference power usage in the camera between those. In summary, target (sensor) temperature is not the only thing to consider for this camera per my experience.

Stephen Garretson:
I read and generally follow the guidelines from ASI/ZWO to match the temperatures for darks and lights as a critical aspect of ccalibrating out the "amp glow" with this camera. This summer we have had lots of pretty warm days in Colorado. My 183s sometime struggle to get to the -20° mark of my dark library frames. I have noticed lately that if the camera is warmer by a bit the artifact doesn't completely calibrate out.

Does anyone have a suggestion for tollerance re: matching darks and lights temps? For instance, I use saved -20° darks; if my lights are -18°, will that work? How much difference can there be? 1°, 2°?

...thanks, Stephen

Hi Stephen. Sorry for such a late response. I haven't been active on ABin forums much before, but, I think that will change here. I don't seem to get notified of forum posts, and I get innundated with image post notifications, so I may need to change my notification settings.

Anyway. It is best to exactly match the temperature of  your lights and calibration frames. A couple of degrees probably won't matter a ton, and you should be able to use -20 degree darks with -18 degree lights. It won't be perfect, and since this camera does have the glow, there might be some remnant there. 

Generally speaking, I think most people have two sets of darks. One for winter, one for summer. OR a master dark for winter, and one for summer. The more significant issue with trying to cool too deeply, is that if the cooler hits max power, its ability to maintain or regulate the temperature to your chosen setpoint is lost. That's not good. You do not want to cool to maximum power, but instead to ~80% power, maybe 70%. This ensures that the camera has some leeway to adjust the power of the cooler up or down as the ambient temperature changes. 

So, if you need to reduce cooler power, say to cool to only -10C, during the summer, then you should do that. And then just get another set of dark frames at -10C, and make a new -10C master dark. You can then switch off through spring and fall, from the "warm" setpoint to the "cold" setpoint, and switch which master dark you use to calibrate during the "cold season" vs the "warm season".