I am just returning my second ASI174MM-C to OPT. The first appeared to work fine except it would not cool below +7˚C in a 29˚C ambient room. The second did better -0.7˚C but was still substantially out of spec (35-40˚C delta T). I might have kept that if it weren;t for the fact that this one ignored the on/off switch and set point in SharpCap and appears to just run at 100% as soon as the DC power is applied. So, the temperature is unregulated and floats with ambient and other factors. I also bought a ASI224MC-C and its cooler appears to work perfectly. In that same room I set it to -15˚C which it had not trouble meeting with some head room to spare. However, that camera, as I report in another thread, seems to have horrid noise issues. I do not rule out operator error, but at -15˚C across a wide range of gains from 0 to 450 in 16 bit mode with 15sec exposures of M14 it produced subs that were unusable as a result of a weird irregular noise pattern that was not periodic on either axis and did not have the character of amp glow. Lengthening exposure to bring the curve smack to the center of the histogram and well off the left axis did not render the noise less visible. Of course the evil orb was out and about full so there was a lot of sky glow. I hope someone can comment on that other thread and show me what I am doing wrong since the 224MC appears to me to be unusable as it stands. I suspect it is operator error, but I don't see what I am doing wrong
