Best 3 x Barlow?

Muppet Man

Hi Folks, I already have a 2 x Barlow with 25 and 6.5 mm plossl eyepieces. Thinking about getting a 3 x Barlow to give me more viewing options. Looking on ebay, they seem to range in price quite a lot.

http://www.ebay.ie/sch/Telescopes-Binoculars-/28179/i.html?_from=R40&_nkw=3+x+barlow

What makes a good Barlow?

The ones on ebay above wouldn't break the bank, but I want to make sure I get a reasonably decent one. Is the old adage of "you pay for what you get" true here?

Scope is http://www.teleskop-express.de/shop/product_info.php/language/en/info/p5546_Starscope-150-750mm-Newton-Teleskop-mit-Montierung---Stativ.html

I think maximum possible magnification is 300 x (or just less). I suspect usable is much less.

TIA
Muppet Man

Tzetze

Check out the customer reviews on these Tal Barlows. "Best budget barlow". Finding one might be difficult though.

Nerro

Hi,
what apeture is your scope?are you planing doing some imaging with it?
3x barlow is usually a bit overkill...unless the conditions are perfect and you have a decent size scope to use it.on a night out i rarely going over 150x magnification.usually its around 100x or less...

Muppet Man

150mm (6")

Yeah, I had hoped to stick a web cam on it at some point.

Nerro

what are you planing to observe?is it doubles or planetary?there is a good Barlow for sale on IFAS.for 65e you can't go wrong
http://www.irishastronomy.org/index.php?option=com_kunena&func=view&catid=17&id=96599&Itemid=40#96599
I have never done planetary imaging so can't really tell how it performs for that as it is achromatic.

Popoutman

Best barlow is a TeleVue Powermate or equivalent device. Pricey but definitely worth it for most people. This device just gets out of the way.

Personally I would steer clear of budget Barlows, they are an absolute waste of cash (Tal components excepted). I have a "Soligor" barlow and the only use I have for it is on the PST, the fringing is terrible on it. I have a 2x TV barlow, and that is a whole lot better behaved. I wish for a Powermate though at times.

That price for the TV 3x barlow is a good one - you'd not regret the performance you'd get with it. You'd only get to use it with the 25mm eyepiece though. With a 3x barlow the equivalent focal length of the 6.5mm eyepiece is 6.5/3=2.17mm and that's far too short to use effectively with scopes of f/4.5 or longer.

Muppet Man

Thanks for the Tip! I'm checking it out now...

Muppet Man.