Dew Heater vs. Dew Shield...

[emadmoussa]

Long story short...

Is it me or dew shields don't withstand dew for more than hour?

Alternatively, dew heaters..never have any experience with them. So wondering, how effective are they? And are what the best yet cost effective products?

Thanks!

[Jammy]

I've got a dew shield. It does work, but if the humidity is bad, it soon stops working. I've bought a dew heater tape, but with all these clouds I've not had chance to use it yet

[JamesF]

I've struggled with dew shields on my scopes and with camera lenses and have come to the conclusion that for extended periods of use heaters just make sense given the option. Extending the dew shield can help, but doesn't resolve the basic problem.

James

[swamp thing]

Less than an hour eh! Sounds like your observing location is very damp. In which case I'd go with both. I used to use both on my old 16" Dob I even carry a 12v hair dryer (Justin Case )

Not much worse than losing an observing session because of dew. Specially if you've driven an hour to get there

[E621Keith]

You need both. Dew shield slows dew formation while the heater clears up the dew that gets through. Sometimes I found the heater isn't powerful enough to clear up all the dew on its own and it eats batteries.

[emadmoussa]

What are the options available for 80ED and ST80?

[E621Keith]

What are the options available for 80ED and ST80?

Dewshield comes as standard for both, so you only need dew heater tape for them.

[Tinker1947]

My ST80 has the supplied Dew Shield it work for a while but then loses the battle, a 5" revelation dew strip attached and powered up leaves the main lens crystal clear, if you don't have a dew heater get one......i keep the voltage around 5-6 volts on a 13.8 variable supply......the picture shows 2 heater supplies.....

[M4lcs67]

Definitely both. With my 127 SLT I managed with just the shield, but with my bigger scope I need them both otherwise it would be a pointless exercise even setting up. SCT's are a dew magnet as well which doesn't help things.

[space3]

I started out with just a dew shield on 925, now I use a heater also,

[Alan_B]

Dew heater bamd is a must on my C8 and I use it in addition to a dew shield. My 127 MAK doesn't suffer to the same extent so I get away with just a dew shield

[bomberbaz]

I have both. Dew shield only for ahort sessions, up to around an hour i have been ok. My ahield is one of the plastic ones. Now i may be wrong but my thougght is the plastic cools very quickly and attracts the moistness very effficiently. So the homemade, campbed versions will work, but i dont think they will be as effective as the foam structure wont get as cool as the plastic. On dew straps/heaters, i bought " dew not" straps. (8" sct in case you wonder). They are really good imho. I have nothing to compare with but battery drain is pretty reasonable on my 17Ah tank. The chap i got it of said it was around 1Ah per hour and with the EP dew strap and GOTO motor. Also dew not straps do nott need acregulator. Using them, I should reasonably expect about 6 hours before Tank gets overdrained. Tbh the longest I have used the whole setup for was 4 hours. But to cut to it, if you have an SCT or similar, i think you need both.

[Astro_Baby]

Depends on the scope type. Never had a dew problems with my TAL100 with its factory standard dewshield, never had a problem with my 200 newt with a dewshield, my Mak 180 needs a dew shield and a heater. I have an astrozap heated dewshield for it.

The worst dew ai have seen was at SSP a few years ago. Dew was awful but the newts dewshiled kept it free of dew. The dewshiled alone couldnt keep the Mak dry though, after that I coughed up for a dew heater and the heated dew shield.