Recommended Barlow Lens for CELESTRON ASTROMASTER 130EQ?

Thargor

Hello everybody. Thread title says it all really, can anyone recommend a cheap Barlow lens or any other type of lens that will improve my viewing experience with this scope, preferably one from http://www.ebay.co.uk/ with the way the exchange rate is at the minute. Heres the scopes website:

http://www.celestron.com/c3/product.php?ProdID=429

Its supplied with a 20 mm and a 10mm eyepiece already. Thanks all.

slade_x

From the sticky on top you can calculate your desired magnifications for that telescope; http://boards.ie/vbulletin/showthread.php?t=2055203633

The 130EQ has a focal length of 650mm so resulting magnifications are:
(mags in blue are usable/ mags in red are unusable)

20mm = 32.5x so w/ 2x barlow = 65x w/ 3x barlow = 97.5x
10mm = 65x so w/ 2x barlow = 130x w/ 3x barlow = 195x

the included eyepieces arent the best selection, as you can see the 10mm is practically useless since they provided a 20mm, favored sizes for a first scope are 25mm/20mm ,15mm and 10mm as paired with a barlow they give you a very nice range with practically all scopes. it really all boils down to the aperature of the scope which tells you the max mag you can use and its focal length telling you what the exact amount of magnification will be, the same eyepieces paired with a different scope will give you different results

With that telescope as you can see from above a 20mm eyepiece with a 2x and a 3x barlow would give you the best range of magnifications for that telescope.

Thargor

Thanks for the quick reply, so do you think this will do the job?

http://cgi.ebay.co.uk/NEW-1-25-CELESTRON-2x-BARLOW-Lens-Telescope-Eyepiece_W0QQitemZ120351830636QQcmdZViewItemQQptZUK_Telescopes?hash=item120351830636&_trksid=p3286.c0.m14&_trkparms=72%3A1300|66%3A2|65%3A12|39%3A1|240%3A1318

Or is there anything better in this list that you can see:

http://shop.ebay.co.uk/items/__barlow-lens_W0QQQ5ftrkparmsZ72Q253A1300Q257C66Q253A2Q257C65Q253A12Q257C39Q253A1QQ_dmptZUKQ5fTelescopesQQ_trksidZp3286Q2ec0Q2em14?_fpos=&_fcid=99&gbr=1

Appreciate the help.

Also, sorry to be a pain in the ass but could you reccomend the cheapest way for me to Collimate that scope?

slade_x

Thargor wrote: »

Thanks for the quick reply, so do you think this will do the job?

No, as i posted above:

20mm will give you 32.5x so with a 2x barlow you'll get 65x and with a 3x barlow you'll get 97.5x
10mm will give you 65x so with a 2x barlow you'll get 130x and with a 3x barlow you'll get 195x


All you need is a 3x barlow or a 1.5x barlow. for example since you have a 20mm it gives you 32.5x using a 2x barlow on it will give you 65x so you dont need to use a 2x barlow on it since you have an eyepiece with half the diameter, the 10mm will give you the same result at 65x without a 2x barlow.

Basically you can get a 3x barlow for use with your 20mm to get 97.5x out of it. or you can get a 1.5x barlow to use with your 10mm piece to get the exact same result

and laser collimators are the easiest way of collimating a newtonian, doing with the naked eye is the cheapest

Thargor

Oh right, there doesnt seem to be any decent 3X Barlow lenses on Ebay though and I dont want to go spending a fortune, do you know anywhere else I can get them?

EDIT: What about this one?:

http://cgi.ebay.com/Multi-Coated-Telescopes-Barlow-Lens-1-25-3x-Eyepiece_W0QQitemZ250345791070QQcmdZViewItemQQptZEye_Pieces_Accessories?hash=item250345791070&_trksid=p3286.c0.m14&_trkparms=72%3A1240|66%3A2|65%3A12|39%3A1|240%3A1318|301%3A0|293%3A1|294%3A50

Thargor

Will that one I linked to work with mine?^^^

slade_x

Thargor wrote: »

Will that one I linked to work with mine?^^^

yes the sleeve is a 1.25mm fitting, thats a standard fitting for the majority of mid sized scopes and most celestrons

Thargor

Excellent, thanks Slade, dont suppose you know anywhere in Ireland that sells them before I order that do you? Or a site in England that will send them over? Theres nothing on Ebay really apart from that one and its in hong Kong so I dont want to wait 6 weeks for it.