Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

RASA 8 - moving between hot + cold

  • Please log in to reply
12 replies to this topic

#1 AbsolutelyN

AbsolutelyN

    Lift Off

  • -----
  • topic starter
  • Posts: 4
  • Joined: 16 Dec 2018

Posted 21 January 2020 - 04:18 AM

Hi. This may be a silly question but I'm a bit concerned about bringing a RASA 8 back inside after a nights imaging in the cold. With my refractor I can put the caps on to help isolate the front element but there will be a camera attached to the front so the cap won't fit. What's the best solution to avoid causing an issues going from hot to cold with this scope? Any thoughts appreciated. Thanks.



#2 RogeZ

RogeZ

    Apollo

  • *****
  • Posts: 1,245
  • Joined: 21 Nov 2004
  • Loc: Palm Beach Gardens, FL

Posted 21 January 2020 - 04:43 PM

If your concern is some sort of thermal shock in between temps, I think that unless you went to extremes you will be ok. Other than that, i would not trap any humidity by putting a cap on the scope right after it went in.
  • elmiko likes this

#3 RogeZ

RogeZ

    Apollo

  • *****
  • Posts: 1,245
  • Joined: 21 Nov 2004
  • Loc: Palm Beach Gardens, FL

Posted 21 January 2020 - 04:43 PM

In other words, I don’t cap my scopes when I go in. 


Edited by RogeZ, 21 January 2020 - 04:44 PM.

  • elmiko likes this

#4 AbsolutelyN

AbsolutelyN

    Lift Off

  • -----
  • topic starter
  • Posts: 4
  • Joined: 16 Dec 2018

Posted 21 January 2020 - 04:49 PM

Thanks. I'm not concerned about thermal shock ... more just same as if you were moving expensive camera kit from freezing to warm -> you keep it in a camera bag to equalise temp. I'm concerned about optics being wet, humidity in the tube, dust sticking to wet optics ... that kind of thing. I'm thinking perhaps a large sealed case to transfer from outside to inside. Perhaps it's just a none-issue. 


Edited by AbsolutelyN, 21 January 2020 - 04:50 PM.


#5 DrGomer

DrGomer

    Vostok 1

  • *****
  • Posts: 191
  • Joined: 07 Aug 2019

Posted 21 January 2020 - 06:26 PM

I'd worry about condensation. Outside for me at night is below freezing. Bringing that inside to my house would turn into a condensation magnet and then I'd have all sorts of evaporation droplet marks on the from optic.  Right now, equipment goes from the freezing outside, capped outside, and into my cold/ low humidity garage...which also helps with thermal equalibrium for bringing it back outside.  Earlier on, I didn't do this and when I left outside equipment inside, everything (mount, camera, telescope) were covered in condensation in a matter of minutes. 

If I had to bring the rasa inside of my house, I'd make up a custom cap or even do something "crazy" like plastic wrap over the front. 



#6 Brule

Brule

    Sputnik

  • -----
  • Posts: 45
  • Joined: 24 Oct 2019
  • Loc: Saint Louis, MO

Posted 21 January 2020 - 08:12 PM

Maybe it's not needed, but for these colder temps I throw my OTA in a large 3mil garbage bag, push out some of the air, seal it with a velcro tie, and then bring it inside my house. I then open it a few hours later, or the next day. I've never seen any moisture on it or the lens when I look at it after. It's simple and cheap, takes me like 30 seconds.


Edited by Brule, 21 January 2020 - 08:13 PM.

  • Tim and Cfreerksen like this

#7 AbsolutelyN

AbsolutelyN

    Lift Off

  • -----
  • topic starter
  • Posts: 4
  • Joined: 16 Dec 2018

Posted 22 January 2020 - 03:09 AM

Thanks for the suggestions - it's the condensation ad humidity that are my worry. I also don't want to be taking off the camera once the spacing is correct. My setup is either in our out, no garage for in-between thermal equalibrium unfortunately. Like the garbage bag tip thanks. I've found a large, seal-able plastic container that I may try first. Even wondering if possible to leave as semi-permanent setup outside to minimise scope disturbance - anyone keep theirs fully setup under a telegizmo or similar for weeks at a time? 



#8 elmiko

elmiko

    Skylab

  • *****
  • Posts: 4,039
  • Joined: 27 Jul 2009
  • Loc: Arizona

Posted 22 January 2020 - 10:16 AM

Doesn't the condensation eventually just evaporate off of the equipment when inside the house? I just bring my cold equipment inside and let it slowly acclimate to the inside temperature then I will cap the scope....after the condensation evaporates.



#9 TelescopeGreg

TelescopeGreg

    Apollo

  • -----
  • Posts: 1,338
  • Joined: 16 Jul 2018
  • Loc: Auburn, California, USA

Posted 22 January 2020 - 02:38 PM

Doesn't the condensation eventually just evaporate off of the equipment when inside the house? I just bring my cold equipment inside and let it slowly acclimate to the inside temperature then I will cap the scope....after the condensation evaporates.

I always end up with the scope capped before bringing it into the garage, because the last thing I do is take my Darks.  The outside of the scope certainly ends up collecting moisture, but I figure that the optics are protected by the cover, and any air that's trapped inside is pretty dry from being out in the cold. 

 

This seems to have worked, but am I just being lucky?


  • elmiko likes this

#10 rgsalinger

rgsalinger

    Fly Me to the Moon

  • *****
  • Moderators
  • Posts: 5,538
  • Joined: 19 Feb 2007
  • Loc: Carlsbad Ca

Posted 22 January 2020 - 03:09 PM

"bringing it into the garage" is probably the easy practical thing to do. I kept my SCT for years in an unheated garage between uses and never once (7 years) ever saw a problem. May be different weather where the OP lives.

 

Rgrds-Ross



#11 MikeMiller

MikeMiller

    Viking 1

  • -----
  • Posts: 802
  • Joined: 22 Jul 2014
  • Loc: Pittsburgh, PA, USA

Posted 22 January 2020 - 03:12 PM

I would be VERY careful moving the thing around with the camera attached. This is how I broke the corrector plate of my EdgeHD; moving with the Hyperstar and camera attached. One little tap as I brought it in the door and CRACK.

 

Now, I never move remove it from the mount when the Hyperstar and camera are attached.

 

The Hyperstar does provide a much longer lever and more awkward to move device than a RASA, so you might be safer. But I will never risk it again. I have a telegizmos cover to throw over it in case of a sudden rainstorm.


Edited by MikeMiller, 22 January 2020 - 03:17 PM.


#12 tcchittyjr

tcchittyjr

    Vostok 1

  • *****
  • Posts: 133
  • Joined: 10 Dec 2012
  • Loc: Orlando, FL

Posted 22 January 2020 - 03:15 PM

Thanks for the suggestions - it's the condensation ad humidity that are my worry. I also don't want to be taking off the camera once the spacing is correct. My setup is either in our out, no garage for in-between thermal equalibrium unfortunately. Like the garbage bag tip thanks. I've found a large, seal-able plastic container that I may try first. Even wondering if possible to leave as semi-permanent setup outside to minimise scope disturbance - anyone keep theirs fully setup under a telegizmo or similar for weeks at a time? 

I have a Telegizmos 365 cover that I leave my MyT/scope/camera under 24/7. I do live away from people, so the chances of it being disturbed are slim, though. It seems to work just fine.

 

TomC


  • elmiko likes this

#13 AbsolutelyN

AbsolutelyN

    Lift Off

  • -----
  • topic starter
  • Posts: 4
  • Joined: 16 Dec 2018

Posted 22 January 2020 - 03:20 PM

Many thanks for the info here... we get lots of dew and moist air here in the UK. Will heed that warning about moving with camera attached! 
 


  • elmiko and MikeMiller like this


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics