Jump to content

NLCbanner2024.jpg.2478be509670e60c2d6efd04834b8b47.jpg

So fogged up...

emadmoussa

By emadmoussa
in The Astro Lounge

Recommended Posts

emadmoussa

emadmoussa

Posted
Posted

Is it normal for your SCT to get completely fogged up in under 15 minutes...?! I don't even live near the sea... :)

By the time I went into the house to fetch the dew shield, make a cup of tea the corrector mirror was totally misty. Funny enough, the stars were still very discernible ...not perfectly sharp, but OK :D

Link to comment
Share on other sites
  • Replies 28
  • Created
  • Last Reply
emadmoussa

emadmoussa

Posted
  • Author
Posted

SCT+Mak's are often refered to a "Dew magnets", That chunk of glass at the front is attractive to moisture.

Very true...especially if you have a reasonably big aperture. Funny enough I never had any refractor fogged up before...then again, I never go more than 3-4 hours maximum when it's cold. :)

Link to comment
Share on other sites
Pig

Pig

Posted
Posted

Imad I have a dew band type heater but not the controller. I simply leave it on max. 

My 9.25 SCT was outside for 3 hours during the peak of the dew count the other night and the corrector plate was fine, the rest of the equipment had a layer of dew :smiley:

It solved my problem from last year at which time I had only a 6" SCT - thus problem solved for me, even with more aperture :laugh:

Link to comment
Share on other sites
Pig

Pig

Posted
Posted

Can I just chirp in with a question? Does the dew heater band cause any thermals to 'wobble' the image...

Not in my experience :smiley:  The heat output is very low.

I am not to sure what the max temp of a controller is, but I cannot see it being very high.

Link to comment
Share on other sites
emadmoussa

emadmoussa

Posted
  • Author
Posted

Not in my experience :smiley:  The heat output is very low.

I am not to sure what the max temp of a controller is, but I cannot see it being very high.

I was thinking about dragging the oven out in the garden to create an engulfed warm environment for me and the telescope :D :D

Link to comment
Share on other sites
DeepThought

DeepThought

Posted
Posted

Can I just chirp in with a question? Does the dew heater band cause any thermals to 'wobble' the image...

If it does than you've probably got it turned up too high.  The trick is to heat the optics by a couple of degrees without heating the air surrounding them.

Link to comment
Share on other sites
knobby

knobby

Posted
Posted

one thing's for sure, you'll see more with optics just above ambient and clear than you will just below ambient and fogged.

Can't argue with that!

just always wondered if it made much difference, I sit around cooling my dob and sit around heating my Mak its a funny old game this astronomy lark :D

Link to comment
Share on other sites
Stu

Stu

Posted
Posted

Just seen this thread. I reckon my mak probably equalled your record at PSP last year as Shane will verify. Had been out cooling for ages, but I had stupidly not left the dew heater on. Took the cap off and didn't get a look through it, fogged up the front plate inside and out, plus the primary! Took a hair dryer next day to fully clear!

Have got some decent dew strips this year so should be sorted.

Stu

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.