Eyepiece and barlow help

[deepind]

Which eyepiece and filter and barlow lens is needed foe celestron astromaster 130eq telescope . ..don't know what to buy...help me ..

 

[ronin]

There is no magic to this. My "rule" is based around the f number of the scope, in your case 5. Others will follow different ideas and what you do is your decision.

The scope is f/5 and 650mm. A 5mm eyepiece is likely going to be as small as the scope will handle comfortably - 5mm = f number of the scope. Technically that will give a magnification of 130x (scope diameter) and an exit pupil of 1mm (reasonable).

Personally magnification has little appeal to me hence my comment elsewhere of a 6mm eyepiece = 108x magnification. Getting a 6mm may not be easy, seems very few around.

So for the high power end 5mm and/or 6mm. 108x is OK for Saturn but that does not appear until middle of next year, so no urgency to get one.

Medium/high then an 8mm or 10mm. The 8mm for 81x is good, 10mm for 65x is good also and both magnifications will be fine for Jupiter

Medium try a 18mm or 20mm, and for wide low power a 30mm is often given.

Barlows ?? Never used one, prefer single eyepieces, filters never used one, don't own one.

Really the scope the mount and eventually 4 eyepieces. That should keep you going for a couple of years. I have been using 4 eyepieces on a smalle scoper as a grab and go package for the last 4 years, actually only use 3 of the eyepieces (8, 12, 25) and I could drop to 2 (those 2 would be 25mm and 8mm). I use the 12mm for solar viewing. The 5mm is there because I have it and one day I might use it, just never have yet.

You do not need 40 to 50 eyepieces, what you do need are a few well chosen decent ones. Specifically if I had your scope I would pick the 8mm, 12mm and 25mm Paradigm = BST Starguider = Agena Dual ED = TS NED (all the same eyepiece).

Problem of saying get A, B,C is that the focal lengths may not be available. Paradigms are good, but so are Vixen NPL plossls (and they cost a bit less) but they do not come in 8mm and 12mm. So it has to be suggestions and approximations.

 

[deepind]

Today I saw a star through 10mm eyepiece ..it was not magnified nicely same as seen in naked eye..so to get higher magnification what eyepiece I need ..eyepiece Or barlow? which is better...I have  celestron astromaster 130eq telescope . .f\5,130-650mm

[Cornelius Varley]

6 minutes ago, deepind said:

Today I saw a star through 10mm eyepiece ..it was not magnified nicely same as seen in naked eye..so to get higher magnification what eyepiece I need ..eyepiece Or barlow? which is better...I have  celestron astromaster 130eq telescope . .f\5,130-650mm

Stars are so far away that you will not see them any bigger with an eyepiece.