Do you have a low temperature limit ? - Forums

Is there a temperature below which you don't shoot ?

It's been 8 weeks since I last had clear sky. At this point I'm ready to shoot under any condition, warm, cold,moon or no moon as long as the sky is clear.

I am wondering though if there's a temperature below which there could be issues with the material.

Where I live in Canada temperature often go below -15° C at night in the winter. Getting below -20° C and even -25° C is not rare in January.

Would there be any issue leaving the equipment outside and ahooting at these temperatures ?

I've imaged below -20C. Sucked because I had to retake my dark frames. I've seen a couple people say their mounts won't work once it gets really cold, but that's never been my experience.

The coldest i have imaged is -9F (-22C) no issues except as Quinn mentioned above retaking darks.

Added note: Last night 20240104 was clear and cold 19F (-9C). Some snow frozen to the dome made closing the slit difficult. Not sure if there is damage so going up to check things, its a 6 hour drive…

I usually don’t image below -12C. Most mounts won’t work well at -15C and cables get brittle, so they can break easy. You may experience binding of the gears below -15C.

-5C is about my limit. When it starts to go below freezing and frost builds up on my gear, I call it a night.

I image from Finland, so like in Canada we do have cold winters. Coldest i ever imaged in was -27C, and there were no major issues other than power from batteries draining very quickly and unexpectedly, as in one moment i looked at the charge readout and it said 40% and an hour later it was almost drained even though i had already spent a good 5-6 hours imaging at that point so the latter half of the charge disappeared into thin air basically. Any issues with the kit in warm weather just gets worse in cold weather - as in if the mount is sticky in room temperature it will probably perform a bit worse in very cold temperatures, but as long as everything is mechanically in good shape all the gear will work nicely is what i have found.

Focusers get a bit sticky too, and might need adjustment in the tension department (if a crayford, like in my scope).

Rodrigo Roesch:
I usually don’t image below -12C. Most mounts won’t work well at -15C and cables get brittle, so they can break easy. You may experience binding of the gears below -15C.

Depends on the mount. I’ve taken a Losmandy Gm811G to -15 F and an AP Mach 2 down to -20 F - the one with the regular encoders. Both worked just fine and did my Optec focusers, 1600MM and 294MM, and my Lodestar guide cam. My 290MM stops working at around 20-25F. The big issue for me at such temps is not the limitations of my equipment but my own limitations for a backyard setup. You can’t wear gloves that are too thick or you lose dexterity, which means doing it in stages and warming my hands periodically. Enthusiasm for braving such conditions tends to be highly variable.

I dismanteled and (in addition to replacing bearings) re-greased my EQ3-2 mount with grease that withstands temps down to -30C, as it tended to act up already at -10C. I have yet to see if and how this has improved the performance. I may get a chance later this week, as the forecast says clear skies and -25C. Other equipment - my cams, AM5 mount etc - seems to work well, at least at -22C, which is the coldest I have used them in so far.

Salut!!

The coldest I imaged was about -30 oc or so (with my star adventurer and also my CEM26).

Bonne Année 2024!!

Marc

Have an AP1100. Here in MN, -24 F is not uncommon, the mount is fine. Have to make sure that I feed it 16 v instead of the usual 12v. I used to have a Celestron AVX that gave up the ghost on a cold winter night.

I’m also in Canada (Ottawa) and image with an ASI1600MM, CEM40 and Eagle3 that perform well enough at those temps. I used to have the ZWO EAF but it couldn’t manage those temperatures. I used to put a hot pack on it every few hours to keep the grease soft enough for the focuser to work. It’s now the first question I ask before I consider new equipment. There are way too many minus 20 nights in Ottawa to not consider cold weather performance.

Clear (and warm) skies!

here is a sample ( zwo 2600mm)
At a cooling temperature of 0 °C, the dark current noise is only 0.0022e/s/pixel. This means a 300s exposure will only cause 0.7e dark current noise, which is less than the readout noise. While at a cooling temperature of -20 °, the dark current can even reduce to 0.00012e/s/pixel, which is completely negligible!

I’m in Michigan (Latitude 43º) and we get pretty cold here as well. A month or so ago we had a couple nights with just a few lingering clouds to do some testing with a fr and it was in the mid teens 15-16ºF and no problems.
I’ve images in -5-10ºF and using my AP1200GTO I’ve had no issues other than as someone mentioned above cables to get very cold and stiff. In the past I’ve had it where connections are not able to be made and then I have to shut everything down and reconnect cabling. So now at that temp usually before I fire everything up I’ll unplug and replug in my USB cords and cabling for my camera, mount, USB hub so there is a fresh connection. As for batteries, I’m in my observatory so I run everything I can on AC and I use TalantCell Lithium Ion rechargeable batteries that have been very solid for me now for 3 years.

Dale

Hi,
I have about -25 deg celsius ( = -11.2 F) here in the north. My bigger Skywatcher mounts (eq8r(h)-series) doesn't work well, the motors begin to stall. But the smaller mounts eq6r and heq-5 and the celestron CGX-L work well.

I usually have my cameras at -25 deg celesius - so it is very nice with only 2% cooling power to them. I use silicon cables as possible for power and USB. But this with the eq8-mounts sucks…

edit: as for the focusers, all our celestron motor work fine but one of the ZWO died completely.

Tom.

Not really, I'm currently running everything in -17 to -18 ambient, it could drop a bit during the night but hopefully not as I'm usually doing -20 on my sensor in the winter months. It can get way below -20 as well, but that hasn't happened this season (yet).

yes, -273.15C .. :-)

Last night I reached -16°C. The two telescopes I used worked fine. The only problem I had were the cables. They got really unflexible and during the mount movement to reach my target, one of the connectors slipped out of the socket. I had to lengthen the cable a bit and then everything worked surprisingly good. I never had much issues like that. So I don't mind those conditions.

CS

Christian