Dew prevention on eyepieces

[Stuu]

Hi Folks. Does anyone have any tricks for preventing dew on eyepieces? I've had a look at heat straps but could do with something a bit more budget friendly. I thought about just putting the cap on when I'm not looking through it but could do with a more convenient solution. 

[Dave scutt]

Hi stuu. 

I was getting dew on my ep's when not in use didn't want to keep putting end caps on and into my case. The ep's I was using more I had on the base of my dob I covered them in a cloth and didn't get any more dew on them before I used them. But living where I am they tend to dew up in the focuser within minutes 

[fifeskies]

I use a heated dew strap laid out flat on my observing desk and just sit them on it when not in use if it is a very dewey night.

Just needs a gentle heat to help keep them clear, at least for a while. (and under some sort of box cover, like a sideways storage box)

On cold high humidity nights cold eyepiece and warm breath can be a nuisance, keeping them slightly warm does help to prevent this.

 

A hot water bottle in the bottom of a tray to warm them also works.

[Carbon Brush]

Around 10 years back I made a heated box.
A fibreglass box, large lunch box size.

Inside there were  couple of power resistors on an ali plate to spread the heat, and a small fan to distribute heat and encourage evaporation.
Just connect to the 12V supply and forget about it.

When swapping eyepieces, just store them in the box and they will be warm and dry when next used.

Of course if you use the same eyepeice all evening it won't help.🤨

David.

[HiveIndustries]

Actually, I had a related thought the other day I'll ask the question here, is there any reason you wouldn't want to use a fridge to get your EPs to temp prior to the evening? If so I kind of wish I had a wine fridge for fall.

As of late I've been running into the fact that my telescope may be in a garage, ready at ambient temps but my EPs are coming from inside and gets fogged even when the primary/secondary mirrors are clear.

[Mr Spock]

I keep mine in pockets 

[Spile]

6 hours ago, Mr Spock said:

I keep mine in pockets 

That’s what I do. KISS

[Stuu]

Thanks. It was more for when they're in the focuser as I make notes and look things up on my phone while observing (keeping one eye covered) so it's for those gaps. I like the ideas for the ones not in use though 🤔