SCT ready for lift off!

[Knighty2112]

A while back I read a post created a few years back I think it was about insulating an SCT to reduce thermal currents in it. After which I bought some insulation to do this, and yesterday I got around to fixing it to my C8 SCT. Got it out last night for an hour after 1am. Didn’t see any drawbacks to it. Of course it was very warm last night, so the proof of the pudding will be when we get colder nights coming back in, so I’ll try and update this post occasionally to let you know if it is worthwhile to do. Just ordinary parcel tape holding it on to th scope at the moment, but if it is to become a permenant fixture to the SCT then I will get some silver tape to give it that extra lunar module kind of silvery look.  

[LightBucket]

Surely that will hinder the cool down, which is very important with SCT, as it is needed to give the best views...? Or am I missing something...

[Mr Spock]

I'd be interested to hear your results. I know some others have found insulating SCTs to be beneficial.

[johnturley]

Looks like you have one of those desiccant caps fitted (from FLO), to try and prevent condensation on the inside of the corrector plate ?

John

[Knighty2112]

37 minutes ago, LightBucket said:

Surely that will hinder the cool down, which is very important with SCT, as it is needed to give the best views...? Or am I missing something...

You would have thunk that wouldn’t you? Quite a few people swear that it does the trick, so I’m putting to the test over the next few months to see if it a winner or a clunker! 

[Knighty2112]

23 minutes ago, Mr Spock said:

I'd be interested to hear your results. I know some others have found insulating SCTs to be beneficial.

Yep! Watch this space!  

[Knighty2112]

11 minutes ago, johnturley said:

Looks like you have one of those desiccant caps fitted (from FLO), to try and prevent condensation on the inside of the corrector plate ?

John

It’s does look like one doesn’t it, but that is my ZWO ASI 120 mc camera ready for action!  

[Stargazer33]

1 hour ago, LightBucket said:

Surely that will hinder the cool down, which is very important with SCT, as it is needed to give the best views...? Or am I missing something...

My understanding is that the thermal currents are caused by the tube body cooling rapidly as it is contact with the cold night air. The air inside the tube being warmer than the now cooled tube causes the currents. If you insulate the tube from the cold air it will be nearer in temperature to the internal tube air. Being little or no temperature differential between the tube and internal air, tube currents will not form.

[dweller25]

1 hour ago, Stargazer33 said:

My understanding is that the thermal currents are caused by the tube body cooling rapidly as it is contact with the cold night air. The air inside the tube being warmer than the now cooled tube causes the currents. If you insulate the tube from the cold air it will be nearer in temperature to the internal tube air. Being little or no temperature differential between the tube and internal air, tube currents will not form.

Correct

I tried this idea last winter with a C6 and initially it did not work.

Then after being given some advice i added a second layer of insulation - that did the trick.

There were two advantages

1. Scope is ready to use immediately

2. Scope takes significantly longer to dew up

Your C8 will need two layers for best results ?

PS - The insulated C6 is performing well on the planets - it is almost as good as my TSA102 !

[Knighty2112]

33 minutes ago, dweller25 said:

Correct

I tried this idea last winter with a C6 and initially it did not work.

Then after being given some advice i added a second layer of insulation - that did the trick.

There were two advantages

1. Scope is ready to use immediately

2. Scope takes significantly longer to dew up

Your C8 will need two layers for best results ?

PS - The insulated C6 is performing well on the planets - it is almost as good as my TSA102 !

Yeah, I was thinking of giving it a second layer on top as well. Plenty of it left to do this, so I’ll put another layer on soon.  

[celestron8g8]

I think it will be beneficial mainly in the winter or high humidity times . But as mentioned remember that SCTs’ need that cool down time for best views .