I need help?

1 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    April, 2012
  • From: North Carolina east coast USA
I need help?
Posted by stepping beyond on Wednesday, September 18, 2013 3:46 PM

I have an 80eq and I looked in the OTA one day and noticed dew or something spotted my lens inside the 3" dew shield that is built on. My question is how long and how would someone wait to clean the lens and the built in dew shield doesn't come off. Any takers for such a trivial ? that I probably already know the answer.

  • Member since
    November, 2009
Posted by Poppa Chris on Wednesday, September 18, 2013 10:38 PM

Try judging the need for cleaning by your view through the eyepiece.  Can you see a blemish in your view?  Chances are you can not since the image is focused on infinity.  If it shows up in photos taken with the scope, taking flat frames and adding them to the image stack along with the Lights and Darks would remove most of the spotting artifact from th eimage.

Typically, one should avoid cleaning coated optics until really necessary.  But if you really have to do it, a solution of 1 quart distilled water, 3 drops dishwashing detergent and 1/2 cup of rubbing alcohol works good.  Or better yet, there are commercially available solutions and cleaning kits from several of the better telescope vendors such as Orion or Agena Astro. 

---Poppa Chris---

Denham Springs, Louisiana USA

"Second star to the right - Then straight on until morning!" - Peter Pan

Celestron CPC1100GPS (XLT) - 279mm aperature, 2800mm Focal length. (f10) Celestron Ultima LX (70deg AFOV) Eyepieces 32mm thru 5mm, Canon EOS Rebel T2i DSLR, Backyard EOS imaging software, Orion Star Shoot Planetary Imager IV, Celestron Skymaster 15x70 binoculars


Join our Community!

Our community is FREE to join. To participate you must either login or register for an account.



Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter.

Find us on Facebook