Don't have a problem with dew....

[badgerchap]

OK I'm waiting for people to throw things at me but....

I have no problems with dew. Sometimes if I stay out veeeeeeeerry late it can just show the first signs, but otherwise I rarely see the stuff. Am I doing something wrong??!

I live by the sea, like, right by it. My altitude is 39m, on the West Coast of Wales (Cardigan Bay). There is a large hill with pine trees right behind my house, and I am very close to the house (<5m) when I use the scope. I use a small frac and a fast newt with a large ish finder on it. Does any of that make a difference?

Anyway I'm not complaining obviously, but I'd be interested to know why this is, especially if there's some intrinsic reason that means I don't have to cough up for a dew heater and tapes

[Daniel-K]

you must very lucky my fast newt its like a dew magnet even with all my dew shields on i still have to blast it every hour with the hair dryer

[ArmyAirForce]

Would the salt air by the coast affect the dew point?

[billhinge]

No, I'm on the east coast about 70 feet above sea level, less than a mile from the sea and we can have very high humidity 95% +, a good night is about 80%

[badgerchap]

No, I'm on the east coast about 70 feet above sea level, less than a mile from the sea and we can have very high humidity 95% +, a good night is about 80%

Do you find your temperatures a couple of degrees above the rest of the country? We are normally about 2 up on the next town inland, maybe this has something to do with it?

[billhinge]

Yes, we are warmer in winter, cooler in summer due to sea breeze - funny when we get snow there is a noticeable difference only a couple of miles inland from us

[John]

I have a couple of refractors and a newtonian and don't usually have dew issues with those either. Our house is on a hill around 300 ft high on the edge of the Severn Estuary.

When I've had schmidt or maksutov cassegrains I did get dewing though so a dew shield / dew tapes were needed then.

[billhinge]

I guess altitude is the key thing, my parents house is at the bottom of a hill, they used to get a lot of fog, the town at the top used to get less

Badgerchap is at nearly twice my altitude which may explain the difference despite both being close to sea

Having said that with dew shields and tapes I have no problem other than having to look through a murky atmosphere

[nightfisher]

I have the 180 mak and they are renowned for the corrector dewing up, but it has the overly long shield that works so well, and on the rare occasion i get to use it, like at star parties, when i take a break from the ep, i put the covers back on

[Moonshane]

I rarely get dew problems either (other than on the finders). I use large fast newts and live about 100m asl. I do use dew shields though. the one time my primary dewed was at PSP 2012 when I left the scope pointing up in foggy conditions after I stopped observing Jupiter - it was no longer visible. you could literally see the fog dropping out of the air - maybe it was low cloud. serves me right.

[Mike73]

My local dark site probably has an elevation of about 100m and is pretty close to a cliff overlooking the sea, dew has only stopped me observing once and it was a really bad night, it looked as if I'd been caught out in a shower!

[nightfisher]

I rarely get dew problems either (other than on the finders). I use large fast newts and live about 100m asl. I do use dew shields though. the one time my primary dewed was at PSP 2012 when I left the scope pointing up in foggy conditions after I stopped observing Jupiter - it was no longer visible. you could literally see the fog dropping out of the air - maybe it was low cloud. serves me right.

Shane, have you seen my diy finder scope dew shield, works a treat

[StarSteve]

OK I'm waiting for people to throw things at me but....

I have no problems with dew. Sometimes if I stay out veeeeeeeerry late it can just show the first signs, but otherwise I rarely see the stuff. Am I doing something wrong??!

Could it simply have to do with some pattern you aren't aware of? If I understand it correctly dew happens when the temperature goes down since colder air can't hold on to as much moisture as warmer air, so the surplus moisture condense. So perhaps it has to do with your observing habits? If you aren't out observing when the temperature drops (for example if you tend to observe later in the night) then it would make sense that you have less of a dew problem. Just an idea.

Steve

[badgerchap]

Could it simply have to do with some pattern you aren't aware of? If I understand it correctly dew happens when the temperature goes down since colder air can't hold on to as much moisture as warmer air, so the surplus moisture condense. So perhaps it has to do with your observing habits? If you aren't out observing when the temperature drops (for example if you tend to observe later in the night) then it would make sense that you have less of a dew problem. Just an idea.

Steve

could be Steve. I tend to set up quite slowly whilst cooking the dinner, and so the scopes are usually not out til quite late I suppose. It'll be interesting to see what happens over this summer, as my kit was knackered so I didn't get much observing done.