wot barlow to buy?????

[bully007 (Bruce)]

not sure wot type to buy for my sw- 600 ????????
I have 6-10-15-25mm 1.25 also have a 2in adaptor no 2in eye pecies though !! any adv welcome.

[mark3d]

hi... i bought a Guan Sheng (GSO) 2" ED barlow and it seems good to me. i doubt id notice much improvement with a more expensive one, and for that matter i probably dont even need the ED version but i took a punt each way it seems liked the right price/quality point for my level.

[Stephen65]

A 2x barlow would be most useful, hard to go past the Televue for $119.

[doug mc]

A 2x or 3x barlow will work best with most short to medium focal length scopes. When you push the focal ratio too far, the depth of focus is lengthend, resulting in in focus dust particles in the field of view. Avoid going beyond F24.

[AlexN]

Also you have to think about the limiting magnification of your scope, and the eyepieces you already have... with my 8" skywatcher, my 3x barlow + 10mm eyepiece combination can only really be used on nights of exquisite seeing... more often than not the 10mm + 2x barlow is the maximum I can go...

If you have the money to throw about the TeleView 2.5x Powermate is a beautiful piece of equipment... the difference between a Powermate and a barlow is pretty substantial..

I've not noticed much of a difference between standard barlows and ED barlows, however.

2x barlow or 2.5x powermate is about big as you'll want to go in my opinion.... after that you really hit the point of diminishing returns.

[overlord (Charles)]

I too have an 8" skywatcher f5 with a 3x barlow i got off ebay for total $28, which is pretty average quality.

It's a let down, Jupiter at *300 is high contrast but poor resolution. But at least it looks sharper than at *150. At 300x its hard to focus and annoying to track manually.

I just content myself with a 100x, 10mm plossel for planatery now.

Reconsider your need for a barlow. Instead perhaps go for a smaller eyepiece to give u perhaps 150-200x? Higher mags are rather overkill in most amateur scopes. U won't use it much.

[Dennis G]

The F number. The primary mirror is F5 and you use a x2 Barlow with a Toucam which I'm told is x6, what is the final F number?

[Ian Robinson]

Lumicon 1.8x Barlow - does coma correction and field flattening too , (but I think it's discontinued).

[Ian Robinson]

Wouldn't bother with more than 2x on a barlow - unless I've a monster piece of glass and lots of spare light.

[PCH (Paul)]

Originally Posted by Stephen65

A 2x barlow would be most useful, hard to go past the Televue for $119.

Agree with this. I have the TV 2x and confirm that it is the expected TV quality.

Cheers