Dew shield - when to put on?

[Adam Y]

Hi - I hope this is a straightforward question.  I've just purchased a dew shield (not heated) to try to help with the dew build up.  The other evening, I brought my telescope outside and set it up a good 3 hours before it was time to use it.  I did maybe an hour of observation of various things (just trying to learn the scope as well as get the processes down in the dark).  At the end, I noticed that the front-end glass was covered with a fine layer of dew - no wonder things were getting hard to focus!

 

It wasn't particularly cold or humid really, but I guess the dew point was high enough.  Thinking a dew shield might be a first good step, but on to my question - do I put the shield on in the house before I bring the scope outside (so everything starts from the same point)?  Or after setting it up outside (potentially trapping a column of moisture)?  Surely at the first sign of dew is too late, so that's out.  Overthinking it as usual?  I will probably end up with some heated arrangement but wanted to start simple.

 

What say you?  

adam

[Nightspore]

 

I set mine up with the rest of the gear.

 

 

The longer the shield, the longer before dewing takes hold.

[Adam Y]

Thanks, @Nightspore

 

I'm slowly narrowing down the extra bits I need to buy as I use it and discover where things could be better.  Dew shield is on the way!  (along with the vibration pads - I forgot how much just the dog trotting by can affect things!)

[Nightspore]

1 hour ago, Adam Y said:

Thanks, @Nightspore

 

I'm slowly narrowing down the extra bits I need to buy as I use it and discover where things could be better.  Dew shield is on the way!  (along with the vibration pads - I forgot how much just the dog trotting by can affect things!)

 

You're welcome. I've never needed vibration pads. A dew shield OTOH is often a necessity, particularly in the autumn months. I have telescopes with integral shields (some retractable) but I still add a shield anyway.

 

 

I've dabbled with heater strips and have heated flexible shields. 

 

 

More often than not I just extend the shield on my refractors by adding a flexible one.

 

 

Most cat's need a dew shield as the meniscus/corrector plate is usually exposed.

 

 

Edited October 30, 2022 by Nightspore
bad spells

[Adam Y]

Dew shield worked like a charm on last night's session! 

 

The vibration pads... jury's still out on that one, hard to say if they made a difference.  Guess they provide a nice stable spot for the tripod legs in the grass. They certainly didn't change the wild shaking that occurs when I even think about touching the focusing knob... 

[TerryMcK]

I don’t think you need anti vibration pads when setting up on the grass Adam. Better to let the spikes of the tripod sink down to the soil. If you are on decking then the vibration pads might work better at suppressing light footsteps. Other than that they are not much use elsewhere like on tarmac or concrete unless of course you are by a railway track or busy road.

[Adam Y]

Thanks Terry - I'll keep that in mind.  I do most often use the scope on the decking, and the dogs seem to enjoy trotting back and forth around it so I figured they'd help.  But you're right, didn't seem to make much difference on the grass.  Appreciate the advice gents!