11mm DeLite

[PSALM19.1]

Hi...just bought a DeLite 11my ep...thought I'd test it out on the Moon tonight in my 8" Dob. I just can't focus down on the Moon...not sure if it's faulty or I just don't know what I'm doing...?
:sadeyes:

[m11]

Hi Shaun,

Just to confirm, if you use a different eyepiece does it comes into focus? If not , could be the collimation is way out.

Sometimes i have to adjust the eyepiece to be further out and rack it out as well.

Also found the moon sometimes hard to test eyepieces on.

[Startrek]

I own a swag of Televue eye pieces
You probably can’t focus due to possibly the following-
1/ Televue eye pieces ( including Delites ) have an adjustable barrel to allow you to slide the eye piece top section and guard in or out to find your optimum pupil distance. Try some different settings ( there should be instructions in the box )
2/ The moon is at full moon phase now and extremely bright which can cause havoc with your vision ( not the eye piece) Make sure your using a good quality moon filter on your eye piece ( best time to observe the moon is around 40% to 70% waxing or waning )
3/ Try focusing on a bright Star first , like Sirius or Rigel Kentaurus, you should be able to see diffraction spikes leading away from the core of the star once you have tight focus
4/ Check collimation of your dob, very important !!
5/ Do you suffer from Astigmatism in one eye or both ?? You can’t correct focus with Astigmatism. You can only correct focus with your telescopes focuser if you suffer from myopia ( long or short sightedness
Televue have an accessory called Dioptrx which can help with Astigmatism

Hope the above is a start and others can pitch in and suggest more ideas and help
Cheers

[Tropo-Bob]

Try using the telescope during the day to see something in the distance, like a mountain or far away tree or building.

Re aprox allignment of mirrors, take you EP out of the focuser and look down and see if U can see you eye reflected in the secondary mirror. If U can't, U need to make the appropriate adjustments to the mirrors:- In essence, U would then need to collimate your scope.

[PSALM19.1]

Thanks guys! Yes, have used another EP and was fine...collimation is fine too. I'll give it a crack during the day, see if I can get somewhere :thumbsup: