I currently only have a 10mm and 25mm eyepiece. I just bought a barlow 2X today. Can anyone explain the formula on what magnification I have now and also, what are some other eyepieces I should own?

flag8r77:

I currently only have a 10mm and 25mm eyepiece. I just bought a barlow 2X today. Can anyone explain the formula on what magnification I have now and also, what are some other eyepieces I should own?

Divide the focal length of your telescope by the focal length of the eyepiece.

For example: I have a 10" Newtonian with a focal length of 1200mm

1200mm / 25mm = 48x magnification

The Barlow simply multiplies that by its value.  2x 3x etc..

Without going into more detail here, as for the eyepiece you should have, I will refer you to a couple other threads in the Accessories forum

Have A Nice ___________

 So you have 48X, 96X, 120X, and 240X. I bought that hundred dollar Celestron kit, and although I've enjoyed it, I think it would be nice to have one or two higher quality, wider FOV EPs. To fill in the gaps, maybe something around 6mm (200 if 120X doesn't quite get it and 400X if you want to really push it), and something wider FOV for big open clusters and stuff like that.

goon:

 So you have 48X, 96X, 120X, and 240X. I bought that hundred dollar Celestron kit, and although I've enjoyed it, I think it would be nice to have one or two higher quality, wider FOV EPs. To fill in the gaps, maybe something around 6mm (200 if 120X doesn't quite get it and 400X if you want to really push it), and something wider FOV for big open clusters and stuff like that.

I was only using my telescopes focal length as an example. I have no idea what his telescopes focal length is.  Those magnification might be different.

flag8r77:

"So you have 48X, 96X, 120X, and 240X" I have all of those? I only have a 10 and a 22x and a barlow.

If your telescope is a 1200mm focal length, then yes you will have all those. 
With the 25mm  you would have 48x 
With the 10mm you would have 120x 

With the 2xBarlow it would be 96x with the 25mm eyepiece, and 240x with the 10mm eyepiece.

But that is only if your telescopes focal length is 1200mm.  You need to divide the focal length of your telescope by the focal length of your eyepieces to calculate the magnifications.

Have A Nice __________ 

 Yeah. 1200/25=48   and with 2X barlow  48x2=96

           1200/10=120     with barlow        120x2=240

You're good to go, but you'll never be satisfied. I want a binoviewer.
 

binoviewer?

binoviewer.

I'm gonna ask about it in accessories.