Condensation on Mirror and Camera

[Tommohawk]

Hi all.

One of the obvious problems of mid-summer imaging is that you can't really get started til very late. Which makes for a very late night.... so, I was thinking of just leaving my kit running all night.

I've surpised just how much condensation accumulates even over short period on a balmy night. So the question is, if I leave stuff running am I likely to get gallons of condensation on my mirror and will this damage the mirror, and secondly is the camera sensor likely to suffer, and thirdly will condensation on the camera body get into the gubbins and damge it?

I know there are dew prevention systems for refractor scopes - but is this advisable for reflectors too? And how do you stop dew on the camera body without heating it? Just put it in a bag? Equipment as signature.

thanks in advance!

[Leveye]

If you use either a coma corrector for a reflector or a field flattener with a refractor you don't have to worry about condensation getting inside the camera body and it's sensor.

[Uranium235]

I wouldnt advise putting the camera in a bag because it will lead to a buildup of heat on your sensor. Ive had my 1000d encrusted in ice before and it was fine (in fact it gave me the cleanest subs ever!).

Your biggest problem of unattended imaging is a meridian flip. You can go perhaps an hour or two through the meridian, but any longer than that and you will risk a mount collision - the nightmare scenario (think broken mount or telescope and youre close).

[Tommohawk]

If you use either a coma corrector for a reflector or a field flattener with a refractor you don't have to worry about condensation getting inside the camera body and it's sensor.

Ahh - never thought of that. Currently I dont have a CC - but do you think the sensor heat

I wouldnt advise putting the camera in a bag because it will lead to a buildup of heat on your sensor. Ive had my 1000d encrusted in ice before and it was fine (in fact it gave me the cleanest subs ever!).

Your biggest problem of unattended imaging is a meridian flip. You can go perhaps an hour or two through the meridian, but any longer than that and you will risk a mount collision - the nightmare scenario (think broken mount or telescope and youre close).

Take your point about the bag idea - maybe OK in the winter when heat buildup is less of a problem. I can see that frost shouldnt be an issue but what about dew at this time of year - do you think it would damage the camera??

Thinking about it smae question arises for the laptop - I think this stays warm enough to prevent condensation and in any case could be covered with something.

And am I likely to get dew on the mirror?

Mount collision - good point. I'm thinking I would need about 7 hours, so would need to ensure I have about 100 degrees of RA in hand. Will check that out. I'm looking at M27 which I think will be a problem. Hmmm... looks like a late night!

Of course I dont need 7 hrs imaging so maybe I could use a timer. I have tank for the mount and mains for the camera and autoguider. So probably get a mains supply for the mount and put the whole lot on a timer.

would prevent condensation?

[Tommohawk]

would prevent condensation?

Ehh? Something went wrong - I was trying to say would camera sensor heat prevent condensation?

[Uranium235]

You should be ok with a bit of dew on the camera, mine has been sopping wet at times. But a towel quickly sorts that out. The camera sensor wont generate enough heat to keep dew off the body.

As for your laptop/netbook, I keep mine in a plastic croc-box. It protects the netbook, bench supply and mains power from extreme cold, damp, or unexpected rain. It also doubles as a handy little table when the lid is closed

[Tommohawk]

You should be ok with a bit of dew on the camera, mine has been sopping wet at times. But a towel quickly sorts that out. The camera sensor wont generate enough heat to keep dew off the body.

As for your laptop/netbook, I keep mine in a plastic croc-box. It protects the netbook, bench supply and mains power from extreme cold, damp, or unexpected rain. It also doubles as a handy little table when the lid is closed

I guess I wasnt expecting the sensor to heat the whole camera! I just meant would it keep the sensor and internal PCB free from condensation?

Croc box - neat idea!

[Uranium235]

I guess I wasnt expecting the sensor to heat the whole camera! I just meant would it keep the sensor and internal PCB free from condensation?

Croc box - neat idea!

Probably best to have a chat with Gina about that, she has seen the inside of many a DSLR! Most of the time I use a CCD, which oddly never suffers from dew or frost on the case.

Gina can usually be found in the DIY astronomy forum, drop her a PM and she should be able to enlighten you further.

[Tommohawk]

Probably best to have a chat with Gina about that, she has seen the inside of many a DSLR! Most of the time I use a CCD, which oddly never suffers from dew or frost on the case.

Gina can usually be found in the DIY astronomy forum, drop her a PM and she should be able to enlighten you further.

Ok thanks - I've seen some of Gina's DSLR mod threads .. impressive stuff!