Re: Problems with dew

On 5 Oct 2005 05:26:14 -0700, "Andy Grove" <andygrove73@xxxxxxxxx>
wrote:

>I was attempting to image Mars for the first time a few days ago using
>an 8" LX90 with the Meade LPI camera. I had the telescope set up for 4
>or 5 hours before Mars was in view (I had to wait for it to rise above
>my neighbours house). When I started to take images all I could see on
>my laptop screen was a very bright disc with fuzzy edges. I tried using
>an orange filter and that reduced the brightness and gave me a nice
>orange disc with no detail at all on the surface. Frustrated, I packed
>up the scope and it was only when I got it indoors that I realised that
>the lens was covered in dew. Presumably this is why I could see no
>detail.
>
>For my next attempt I will put the scope out just an hour before I can
>view Mars and I will keep the dist cover on and keep the scope pointing
>down until I'm ready (tips I've read over the last couple of days) but
>my question for the group is .. should I really be buying a dew
>prevention system? I'm reticent to spend more money at the moment as
>I'm already way over budget on my new hobby but am I wasting my time
>trying to image planets in this weather without such a system?

Don't cut down on your cool down time Andy. If the corrector plate
covers with dew, one method of clearing it is to use a hair dryer. A
12V dryer (which can be bought from many astro-stockists) coupled to a
car battery or equivalent will be safe and clear the moisture for you.

Keep using the dew shield too.

Allowing your scope to cool will improve the image quality no end. In
fact if you get a dryer and remove the moisture from the corrector
plate, the heat from the dryer will interfere with the image for a
number of minutes after you finish!

--
Pete
http://www.digitalsky.org.uk
.

Relevant Pages

  • Re: Problems with dew
    ... >I was attempting to image Mars for the first time a few days ago using ... > or 5 hours before Mars was in view (I had to wait for it to rise above ... > the lens was covered in dew. ... > For my next attempt I will put the scope out just an hour before I can ...
    (uk.sci.astronomy)
  • Re: Problems with dew
    ... > or 5 hours before Mars was in view (I had to wait for it to rise above ... > the lens was covered in dew. ... > For my next attempt I will put the scope out just an hour before I can ... dew heater from the US (for about half the price of a similar system from ...
    (uk.sci.astronomy)
  • Re: Tips on viewing Mars?
    ... Make sure your scope is collimated. ... to see the subtle features of Mars. ... small and the field of view of this eyepiece is likely ... To cut down on the substantial glare I use a variable polarizer filter ...
    (sci.astro.amateur)
  • What a morning!
    ... time between university and other activities to do any observing or posting ... which I thought was Saturn. ... So I knew my scope was focused really good, ... Mars was a surprise too. ...
    (sci.astro.amateur)
  • Re: contrast in SCT & MC : Meade, Celestron, Intes ?
    ... experience with Mars, which I'm looking forward to changing now that it's ... Don't second guess your scope. ... > better my old Intes Mak Cassegrain 6". ... > You might consider a larger aperture telescope. ...
    (sci.astro.amateur)