Which Barlow?

[Danoz]

Hi guys,

I'm preparing for a bit of a revamp of my eyepiece collection, the GSO plossels I have are becoming a little frustrating (esp. after joining a club and seeing the difference a $400 eyepiece can make!). I'm after a few good wide field eyepieces for my 8" GSO dob and am conisdering the 17mm and 13mm from the Hyperions/Stratus range as well as a GSO SV 30mm and then perhaps a 5-8mm ED eyepiece for planetary viewing.

So my question is, what do I get to replace my gso 1.25" barlow? With all these big eyepieces esp. the Hyperions with there removable 1.25" section I feel like a 2" barlow is required. I've really only got about $100 to spend so the question is do I go the gso 2" 2x barlow, the gso 2" 2x ED Barlow, or go for quality and get a 1.25" Orion shorty plus (which I can get a friend travelling to the states to pick up for about $100 AUD).

Is the GSO 2" ED Barlow any comparison to the shorty plus for widefields? or is it's only benefit with ED eyepieces?

Thanks for your advice
Dan

[iceman]

Hi Dan.

The Orion Shorty Plus is the best of the ones you've suggested, and probably worth the extra money if you can stretch your budget.

You may as well get the best you can afford now - otherwise if you buy a cheap one, you may be left wondering in 3 months time whether you should've bought the better one.

The TV 2.5x powermate is the best of all, but is not cheap ($300).

[janoskiss]

Orion Deluxe 2" is the best barlow I've used, out of Televue, Orion Shorty Plus, Antares 1.6x 2", Meade #140, all the GSOs and other cheaper ones (and a 5x powermate that is of course of limited use visually). The 1.25" Deluxe is going for $99 from Sirius Optics - I've got one on order.

The internal baffling in the Deluxe makes it the winner with the highest contrast. TeleVue is very good also. Antares 1.6x 2" is a great versatile one also. Add a 1.5" barrel extension to turn it into 2x. I can only recommend the Shorty Plus only if you specifically need a short barlow.

[Danoz]

OK, so silly question perhaps, but do I need a short barlow with an 8" GSO Dob? How would I tell?
thanks,
Dan

[janoskiss]

No the 8" GSO Dob does not need a shorty barlow. They are needed by some scopes that use diagonals, ie, refractors and some maksutovs with limited focuser travel.