Any-one know what's going on here?

[carastro]

After defecting from the Peak Star party the weather forecast in Sussex looked a lot better so I got myself down to a campsite.

I was using my William Optics ZS71 and x.8 focal reducer which I haven't used for a while and got this:

Not dew as I checked the aperture and with a torch I could see all the way down to the sensor.

Also the EFW seemed to be working as I could hear it move but Artemis did not say which filter was being used.

This is a 5minute sub with full stretch.  even the looping images looked similar which was why I just did a 5min sub.

All the bright stars had this weird halo around them.

[Martin-Devon]

I think this is condensation. Your image looks identical to what I saw recently on my imaging rig, so I shone a torch through the top of my scope, only to see what was clearly a sizeable patch of condensation down at the far end of my imaging train. The dew heater was working fine, the issue was on the glass where the reducer was, or somewhere in that region near the CCD. I bought my kit in, dismantled and let it all air & dry out for a few days. Still need to test it again though but weather is dreadful at the moment.

Martin

[carastro]

Thanks Martin, unfortunately not a quick fix then as I am at astro camp.

Carole

[Ibbo!]

wrap a dew heater round it for a few hours or a blast with a hair dryer

its the moisture thats frozen

its worth a try

[Ruud]

It's like a tunnel to a different universe. Very strange.

[carastro]

Well I took it all apart today and everything seemed fine.  What I did find I am embarrassed to say is that I had forgotten to plug my dew heaters into the power last night, but can't understand why the objective lens didn't seem misted up.   

Going to give it one more try.

Thanks for your help every-one.

Carole

[Ibbo!]

its moisture on the coverslip of the ccd

wrap a dewheater round the end of the ccd and it might just be enough to drive the moisture off

It happens to my ccd a few times a year when it has been high humidity I had to zap it with the hairdryer the other night once clear its OK for the night

[carastro]

Thank for your help every-one.

Carole