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View Full Version : What eye pieces do you suggest for 4.5 inch Celestron 114eq? Any advice appreciated.



AstroJoe
2010-Jul-18, 07:30 PM
I have just dove into astronomy and want to know what kind of eye pieces would compliment my telescope. It came with a 20mm which the image is reversed and it came with another 20mm that corrects the image. So what do you all think? What about filters do they enhance images? What are they for? I'm sorry about all the questions but once I seen Jupiter and Saturn, in my telescope I was hooked, my mind is a sponge please advise. Thank you.

Swift
2010-Jul-18, 10:52 PM
AstroJoe,

First, welcome to BAUT.

Second, no foul on you, but I think your post will get more response here; more of the observing types hang out in this forum. Good luck.

redshifter
2010-Jul-18, 11:29 PM
Assuming yours is 900mm focal length, the 20mm will yield 45X, good for moderate field DSO (Deep Sky Object) observing and scanning. A reflector type scope reverses the image as a property of its design. When observing astronomical objects, this is not a big deal, more so for terrestrial observing. For your scope, I might recommend 2 or so more eyepieces plus a barlow lens which will double the focal length of an eyepiece. I wouldn't get an eyepiece that exceeds 175-200 power or so, as that will likely exceed the resolving capability of your scope most every night. I have a 10" scope and I can rarely get beyond 150 power or so because the atmosphere around here just isn't stable or clear enough to allow it most nights.

If it were my scope, I'd get a very low power eyepiece for wide field scanning. For me, that would be a 35mm or so. A 35mm eyepiece in your scope yields about 25 power and right about 4.5mm exit pupil. I'd get as wide a field as I could afford as well. I'd probably keep the 20mm unless it's junk. I'd also get a higher power planetary eyepiece, say about 12mm. That way you have 25 power, 45 power, and 75 power, plus double those when you use your barlow. You might consider slightly different focal lengths than I propose to get as wide a spread of magnifications as possible. Strictly from a magnification point of view, I'd look for about 25X, 40X, 75X, 125X and 200X for a good spread of magnifications.

Here's a pretty good primer: http://www.telescope.com/control/learning-how-to-choose-telescope-eyepieces

I like this line of eyepieces for good performance for the price: http://www.telescope.com/control/accessories/telescope-eyepieces/orion-epic-ed-2-telescope-eyepieces These perform as well as most plossls, but have a nice long eye relief and wide lens for comfortable observing at any magnification.

Sorry if I confused you, we just had 3 foster kids placed in our home and one is an infant. I'm dealing with severe sleep deprivation...