Dew Sheild v Dew Heater

[Andy_Mc]

Hi,

Looking for some advice when choosing a dew sheild or heater? I'm using a Celestron Nexstar 6slt and as winter is coming, I'm reckoning it's going to be an essential bit of kit. I've seen vids of homemade shields, they look great but I've got a budget of ~£50 so reckoning on buying one.

Found this for example 

https://www.rothervalleyoptics.co.uk/celestron-c6c8-flexible-dew-shield.html

Not been able to find a heater suitable yet. 5V USB heaters seem mainly for DSLR cameras 

Did think of heated sheild but its above my pay grade 😃

TIA

Andy

 

 

[CloudMagnet]

I had a similar train of thought when adding dew protection with my Newtonian. I decided to try the dew shield first as a cheap and simple solution and if that didn't work, then try the complex/expensive route of a heater with battery.

I have had no dew problems at all even in 95% relative humidity just using an unheated shield. I would give that a try first as it might be enough and then saves the hassle/expense of a heater setup.

[Zermelo]

Here's an old thread on the same topic:

https://stargazerslounge.com/topic/181765-dew-heater-vs-dew-shield/

and another from across the pond:

https://www.cloudynights.com/topic/645865-dew-shield-or-dew-heater/

I have a 127 Mak and so far I've managed with just a shield, but I've not taken it through a winter yet. If you prefer, you can save a few pennies with a generic shield rather than the Celestron version.

I think most of the larger heaters are 12V and use the phono plug connectors, rather than 5V USB format.  This band for a 6" scope for example, produces 12W, and if that were done at 5V it would draw more current than the standard USB 2.1A socket can deliver. Were you looking for that connector because your power tank has only a USB output?

[John]

When I've owned SCT's and mak-cassegrains in the past I've just used a dew shield rather than a heated dew band. My usual observing site is not that affected by dew usually though so the requirement might be "location dependant"

When I used to take scopes to the SGL star parties which are on a riverside site, dew was much more of an issue and I seemed to need all the dew busting apparatus that I could get !

 

[M40]

I bought and just use a Kendrick dew shield for the skymax but then other than during the star align process, I don't look straight up with that telescope. The dew shield adds about 200mm to the end of my telescope and looking just at the planets or the moon the dew shield works fine, as at the end of playtime, the telescope and mount can be soaked but the corrector plate is dry. So my question to you is what do you look at, if you look at objects at a high angle, then I would say budget for both with a dew shield as an essential item and something to be purchased at the earliest opportunity. Hope it helps.

[Starslayer]

https://www.firstlightoptics.com/dew-prevention/astrozap-flexible-dew-shield.html
 

works well for me with my Celestron 6” sct

[Cosmic Geoff]

A dew shield should be considered an essential piece of kit on a SCT or Mak, just as it is on almost all refractors.  Manufactureres don't like to fit them, no doubt because it makes their product look big and ugly.

I have found a dew shield, either manufacturered or home-made, to be adequate on almust all occasions over several years, but in other locations results may vary.

[Andy_Mc]

43 minutes ago, Starslayer said:

https://www.firstlightoptics.com/dew-prevention/astrozap-flexible-dew-shield.html
 

works well for me with my Celestron 6” sct

That looks really good! Cheers for recommendation.

[Andy_Mc]

2 hours ago, M40 said:

I bought and just use a Kendrick dew shield for the skymax but then other than during the star align process, I don't look straight up with that telescope. The dew shield adds about 200mm to the end of my telescope and looking just at the planets or the moon the dew shield works fine, as at the end of playtime, the telescope and mount can be soaked but the corrector plate is dry. So my question to you is what do you look at, if you look at objects at a high angle, then I would say budget for both with a dew shield as an essential item and something to be purchased at the earliest opportunity. Hope it helps.

It does many thanks²