high power advice

Hi folks. I own a Celestron C11. I am looking for a recommendation for a high-power Televue eyepiece to use with this telescope. There are two ways I'm considering going.

First, I would like a recommendation for a dedicated high power eyepiece. I was thinking along the lines of either a 5-6mm Nagler or a 6mm Radian. Which would be a better choice for my telescope? I think for an 11" CAT, 5-6mm is probably the most powerful eyepiece I should use for most seeing conditions.

Second, I was also thinking about something to use with my 2X Powermate. I have a 17mm Nagler, which gives me about 8.5mm with the Powermate. I'd like to push that up just a bit, though. If I were to use a 12mm Radian with the Powermate, that would give me 6mm, and it would also give me an in between point between 6mm and the 17mm Nagler.

Any thoughts?

Rex Cox

With your powermate, an 11 TV plossl may be nice.
Mike

Hi Rex,

How are your seeing conditions?

I have heard a familiar rule of thumb that 300x is about the highest power you can use under most circumstances, because atmospheric conditions put a lid on seeing. You can use higher powers, but the image just gets bigger - you can't see any more detail. My experience confirms that, although I am interested in other observer's experience. I just read Floyd Blue's post that he uses over 1000x on the moon (!).

So you can always play and use very high power, but you may not be able to see any more detail than if you use a 9mm eyepiece in your scope. FWIW, I had fun viewing Mars at 400x through my 4" APO in good seeing conditions.

I have a C11. I live in Texas, not far from Oklahoma. My wife wears glasses, so I Barlow longer focal length eyepieces. I do plan on obtaining one or two Televue eyepieces. With what I have, on really good nights, I can obtain nice, clear views with 8.6mm (323X). Most nights, I am limited to 10.7mm (262X). My experience is that the highest power eyepiece that you would use with regularity would fall around 8mm or 9mm. Clear Skies!