imaging in sub zero temperature?

[iwols]

Just wondered if anyone had any comments or observations for imaging in sub zero temperatures either planetary or deep sky

[Stickey]

Club mate of mine tried last night found his mount wouldn't work, but he'd left the tripod out earlier in the day and it was frosted up by the time he attached the mount head. 

UPDATE: The problems continued in the warm. It looks like the mount is playing up. 

Edited December 15, 2022 by Stickey
New information from my clubmate

[Rustang]

I was out last night till 11pm with a laptop, scope, mount and camera, some outer items/surfaces ended up with a layer of frost but no other issues, everything worked as normal. I have a home made cover/shell for the laptop which sits on a fold away table, I also keep the laptop on some insulation foam just to try and keep it a little warmer while out. Obviously use dew heaters and I also wrap the back of my reflector to keep any cold air and frost or moisture from possibly getting on the primary mirror.

Just make sure you bring everything in to thaw/dry out until you pack it all away again.

Edited December 15, 2022 by Rustang

[barbulo]

According to my short experience in AP, batteries don´t like the cold. I avoid relying on batteries and have everything pluged in. 

HTH

[TheThing]

Thick socks and a wooly hat are a must.

[DaveS]

Even better is remote connection to a nice warm office.

Looking at tonight I think I will only have a short session as I've been in the habit of leaving a sequence running until the early morning then getting up to close everything down. Don't fancy going out to the obsy in sub zero temps wearing only my dressing gown, brr...

[LaurenceT]

Last week I was doing some lunar and planetary imaging when quite suddenly my Ipad went blank and wouldn't restart. Apparently they have a sub-zero limit, I decided that if it was too cold for the Ipad it was probably too cold for me even dressed as I was.

[Swillis]

1 hour ago, barbulo said:

According to my short experience in AP, batteries don´t like the cold. I avoid relying on batteries and have everything pluged in. 

HTH

Are you running an extension cable out?  How does that cope with frost and dew?

Simon

[EarthLife]

1 hour ago, Stickey said:

Club mate of mine tried last night found his mount wouldn't work, but he'd left the tripod out earlier in the day and it was frosted up by the time he attached the mount head. 

UPDATE: The problems continued in the warm. It looks like the mount is playing up. 

I guess water/frost could have formed on the internal PCB(s), that would cause all sorts of problems with the electronics.

Take a look at the boards, make sure they are dry/clean, and maybe brush (tooth brush etc) them over with 99% isopropyl alcohol.

[Carbon Brush]

Lead acid batteries have poor performance sub zero. Lion are better.

For mains leads, RCD in the house is a must. A poly bag (or outdoor box) to protect 13A plugs/sockets from dew is a good idea.

Laptops, computers, screens, etc. can all be iffy at low temperature. Powering before chilling will help.

Standard mounts and handsets do not have conformal coating on PCBs. They are therefore sensitive to condensation.
They are no better built than your indoor electronics.
Consider DIY coating boards.

HTH, David.
 

[ONIKKINEN]

Depends on how much below 0 we are talking how much trouble it will be.

0 to -10 not much will change, it will be a little bit cold and instead of dew you get frost. Frost is better though and easier to prevent than dew so this is a good thing. Dumb batteries are not worth it in these temperatures, but in my opinion they are not worth it at all, you need some kind of regulated smart power solution or just AC power to use the kit any length of time. Basically all equipment survives this and works as intended without much in the way of hiccups.

-10 to -20 you start seeing the real problems. Mounts will become sticky and difficult/impossible to balance properly because of that but just knowing before hand where to place the dovetails and counterweights solves this easily. Focusers (even good ones) tend to be sticky too. Dumb batteries are useless and will drop below 12v in minutes, its a complete no-go. Coupled with that there is the issue that your mount draws more power because it is getting sticky so you could completely lose tracking/go-to with a simple battery that does not keep the voltage propped up to 13.6v.

Below -20 the same problems continue but every degree more is a chance to develop an additional issue. Mount electronics become unresponsive, like the handcontroller that will take several seconds to change what the LCD display shows you when browsing the menus. The actions themselves do work but the display has a 5 second delay. Computers will likely also have an input delay of a few seconds but they will keep working in the background and complete exposures in a sequence happily. Tablets/smartphones will be slow too, keep them in your pocket/under your jacket to make sure they are operable.

In short, british cold is not a real mechanical issue for astrophoto kit. Even decent cold of say -15 is still a minor issue if you prepare for it.

[barbulo]

1 hour ago, Swillis said:

Are you running an extension cable out?  How does that cope with frost and dew?

I use just an extension cable, routing data connectivity through it via a PLC network adapter (might say "umbilical cord" concept). One mini-PC or RPi running everything outside and a tablet or laptop in the warmth.

[Elp]

Wear around 5-6 good layers, including layering on your head. Sat outside and was outside around an hour at a time and didn't feel the cold.

[CraigT82]

About 6 years ago I bought a big down filled parka coat from millets which was about £100 I think, best Astro investment I ever made. Also have some Karimoor snow fur insulated boots which have been great but are a bit worn out now.  For me it’s mostly the hands and feet that suffer. Haven’t yet found any gloves that keep my fingers warm whilst letting me operate everything without taking them off. The search continues.

[900SL]

I am making an insulated battery box and I'm looking at adding a stone slab that can be heated up before use then act as a storage radiator. Because a 15kg battery doesn't weight enough 😂

My Vixen LCD screen on the SB 10 needs an insulating jacket below 0C. Apparently LCD can be permanently damaged if temperature low enough

I've now got dew heaters so should be good there. I left the mount on the balcony at -5c and the stiction was noticeable. 

I'll likely try to run power from a battery box inside my car, and operate the mount from inside if it's too cold

[EarthLife]

5 minutes ago, CraigT82 said:

About 6 years ago I bought a big down filled parka coat from millets which was about £100 I think, best Astro investment I ever made. Also have some Karimoor snow fur insulated boots which have been great but are a bit worn out now.  For me it’s mostly the hands and feet that suffer. Haven’t yet found any gloves that keep my fingers warm whilst letting me operate everything without taking them off. The search continues.

Heated gloves might be useable ?

ie, https://www.amazon.co.uk/ObboMed-MH-1005-Infrared-Warming-Touchscreen/dp/B078K9FNH5

 

[Elp]

They're bulky but I found the bracemaster waterproof ski gloves quite good. Can't screw unscrew a filter with it but can operate mobile whilst outside easily enough.

[Paul M]

My new RC 10 Scope is about to spend its 3rd night out in freezing conditions. I've just thrown a cover over it during the day to keep the birds off. 

Luckily it's in the back yard and mains powered. So I can have 3 dew bands on full temp. One round each end of the OTA and one round the guide scope objective. In the past I've had both mirrors on my 10" Newt not only dew up but actually freeze.

My imaging PC is an unbranded W10 mini PC. The whole case is aluminium with heat sink styling. That just sits attached to a tripod leg with velcro. It runs just about warm enough to stop dew forming.

The power supply is the Nevada 30A from FLO,  that too keeps itself warm enough to avoid damp.

As for keeping myself warm during imaging I use VNC and one of these

[SteveNickolls]

Best to keep warm indoors and control everything from there using wi-fi or Ethernet. There's the setting up and take down and polar alignment of course requiring a presence outdoors but those jobs can be organised to complete as fast as you can.

Last night was cold for here, around -4.6C but the mount and tripod were free of ice in the wee hours. 🥶🥶

Cheers,

Steve

[Fegato]

My rig is on wheels - I run it a few yards through bi-fold doors onto a patio. I stuck it out on Monday this week and polar aligned, but when the weather failed to live up to expectations left it outside due to positive Wed and Thur forecast. So it's been outside all week now with no problems - 10 hours of imaging last night, and it's on the go right now too. It's been down to -11 here.

I have mains power and ethernet connections to mount and mini PC - I disconnect and bring the wires in after imaging.

I use Telegizmos lightweight tripod and scope covers. Former on the whole time, latter just when not in use. These are not for permanent outdoor use, but work for shorter periods.

The only item I have issues with in the cold is the mini PC. It refuses to start up when very cold. So I also bring this in when not in use when it's very cold, and take out when needed.

 

 

[TakMan]

5 hours ago, CraigT82 said:

For me it’s mostly the hands and feet that suffer. Haven’t yet found any gloves that keep my fingers warm whilst letting me operate everything without taking them off. The search continues.

I would suggest some silk gloves and socks - Jasmin Silk have a decent offering for a sensible price.

https://www.jasminesilk.com/accessories/silk-gloves-socks-balaclavas

You’ll think a thin layer like these will be useless. They are anything but…

It was recommended to get some when the wife and I first went to Lapland more than 10 years ago. Since then we’ve done the Ice Hotel, etc, etc.

Been down past -36 degrees. The idea was that you could whip the snow gloves off to operate the camera (aurora pics, etc), yet still give the old hands some protection from frostbite for short periods.

As a first layer, you’ll be amazed at the difference silks make to the hands and feet.

A nice little Christmas stocking filler to yourself then!

Damian

[AMcD]

I am away from work and have just tried to start a remote imaging session with my observatory at home.  It has been below zero for a number of days now and I find that the DEC axis on my Losmandy G11 is not moving.  This would ordinarily be infuriating given it is a perfect night for imaging, but happily I have just been to the Christmas party at work so I am much more relaxed about it now.  I am left wondering whether the DEC problem has been caused by the extended cold.  I will  investigate when I get back home tomorrow.  I will also have to buy a thank you gift for my lovely wife as I also had to break my promise never to send her to the bottom of the garden to investigate what was wrong 😂

[Craig a]

I was out the last 2 nights, it was -6 everything had a coating of ice but it all worked ok, my kit is permanently setup outside under a telegizmos 365 cover but when I got in after work and looked down the Newtonians tube the primary had started to get ice on it, quick defrost with a hairdryer on low heat and was back for imaging again, to be honest it’s becoming rare to get temperatures as low as this for this long in England these days, everything is running on mains electric though, two laptops one by the scope and an old one in the house where I sit and control it all through AnyDesk, so I was actually watching the subs roll in from the couch 

One thing I did notice though is that I had abit more backlash than usual, I might be wrong but I think the gear and worm probably shrunk slightly due to the cold 

Edited December 16, 2022 by Craig a

[AMcD]

1 hour ago, Craig a said:

I think the gear and worm probably shrunk slightly due to the cold

I wonder whether contraction of the metal parts was my issue.  The DEC motor continued to respond to commands but the DEC axis did not move.  In the circumstances, I wonder whether a set screw shrunk sufficiently to loosen the connection between the motor and the worm shaft such that worm shaft was slipping within the connector.

[Xsubmariner]

Managed 2 nights of imaging without the threat of passing rain, what a joy. The sessions would have been much shorter had my equipment setup necessitated me being outside. Thankfully I now control the equipment from a warm observatory control room. 

This was a far cry from a few years ago when I spent a lot of time under the stars with my NEQ6 and laptop. All was well up to -6, then if the temperature dropped further guiding became erratic and the mount sluggish. Found out later the original grease in the NEQ6 was not able to operate at those low temperatures.

As the U.K. weather becomes more adverse, my reasons for building a back garden observatory are more than justified. This season more than any, has been spent conducting opportunistic grabs between rain and sheltering from adverse weather conditions.  Imaging in the U.K. under the stars in winter is definitely for the young and hardy.