M31 like you've never seen it before!

[martin_h]

Imaging through a frozen CCD chip! - nightmare night.

[BlueAstra]

Why did it freeze? Is it a cooled CCD (-30 ish) in a very humid environment?

[martin_h]

Why did it freeze? Is it a cooled CCD (-30 ish) in a very humid environment?

Yeah cooled CCD - QHY8 - very prone to it - it seems.

[NickH]

QHY's....yeah they never fail do they ;-)...jeepers, hope you get it sorted

[BlueAstra]

Why would some CCD cameras be prone to freeze up while others don't?

[steppenwolf]

A solution that a good friend of mine uses is to fit a heated dewband to the extension tube between the camera and the focus tube - this has completely resolved the issue for him.

Why would some CCD cameras be prone to freeze up while others don't?

It's all to do with sealed cavities (ooh err missus!). Many CCD cameras have hermetically sealed chambers between the sensor and the optical flat that protects it so these cameras don't suffer from freezing up.

[Euan]

It's not just the QHY8, I have the same problem with the Atik 383L+, although to their credit I just got some free replacement desiccant in the post to sort it out

The best way to deal with the QHY8 is to get it in a air proof container overnight with some desiccant. Bern @ MA has a good solution to this and it worked really well for me

[NickH]

Interesting on the 383L+ front, as the dessicant plug is pretty easy to swap over.

[Whippy]

A solution that a good friend of mine uses is to fit a heated dewband to the extension tube between the camera and the focus tube - this has completely resolved the issue for him.

I've had to do that a couple of times when my Atik has had this problem. But it was incredibly dewy on those nights!

Tony..

[martin_h]

A solution that a good friend of mine uses is to fit a heated dewband to the extension tube between the camera and the focus tube - this has completely resolved the issue for him.

I would do that but at the moment I'm using it on a scope with a focal reducer and a filter wheel, so the distance between wheel and camera is only about 5mm - not enough room!

[adamsp123]

One a similar vein does anyone get dew on the filters in their filter wheel?

[NickH]

I've had to do that a couple of times when my Atik has had this problem. But it was incredibly dewy on those nights!

Tony..

Had it with the ART285, never seen it with the 314L, but then it's pretty much a closed setup these days, never comes off the scope

[ollypenrice]

The Atik 4000s have the option of heating the window but I have only need it a couple of times. Steve has the easy solution, I'd have thought.

Olly

[Tim]

Ease up on the deconvolution

Seriously though, on my QHY8 I have completely resolved the icing issue by closing the nosepiece filter in place under a hair dryer, so that the air inside the camera is dry. Make sure not to break the seal once the nosepiece is in place.

Another option that works is to use a variable voltage power supply and thus regulate the cooling. Ask SteveL for details

I used a dewstrap on the nosepiece for a while but found it ineffective.

Also, if you are using a newt to image with, you need to ensure the the camera isnt pointing downwards.

Like I say though, since using the hairdryer method, mine doesn't ice up anymore.

HTH

Tim

[NickH]

The Atik 4000s have the option of heating the window but I have only need it a couple of times. Steve has the easy solution, I'd have thought.

Olly

and again...you wonder why I bought the 4000 and not the 383L+

:-)

[RobH]

One a similar vein does anyone get dew on the filters in their filter wheel?

Never had that issue.

I did occasional get dewing/ice with my old DSI2 when using an outback cooler, but I found that if I set the temperature slightly above the dew point there wasn't a problem.

To get rid of the dew, I blasted the camera with a hairdryer

Cheers

Rob

[Euan]

Interesting on the 383L+ front, as the dessicant plug is pretty easy to swap over.

I swapped them over for 3 fresh new ones, left it overnight and was able to go straight from +10c to -30c with no problems at all

I'm really impressed with the design and the support from Atik, as I live next to the sea I will buy a good stock and just change them every month or so

[Catanonia]

My QHY9 does it sometimes if I leave it out over many nights or i don't do a warm up process.

MaximDL has a nice warm up process to slowly warm the CCD after you have finished.

I sort mine myself by using dessicant in a big zip lock bag over night and assembling the ccd chamber inside the bag.

Normally works well.

Also the QHY9 has a dessicant tube you can attach to the CCD chamber to remove the moisture.