Barlows and fast scopes

[tom714uk]

I know that fast scopes are hard on cheap eyepieces - do I also need to be wary of cheap barlows more with a fast scope than with a slow one, or is a barlow's performance independent of scope speed?

Cheers,

Tom

[michael.h.f.wilkinson]

You will need to be wary of cheap barlows, period. A wider light cone is harder on optics of any kind, and fast scopes tend to need better correction, also in barlows, as you correctly suspect.

[tom714uk]

Thanks Michael!

[Revs]

Agreed, a good barlow is a must, it makes a world of difference. The Ultima 2x (or Orion Shorty Plus 2x) is a good choice. Also, the Tal barlows are good, especially for the money.

[tom714uk]

Also, the Tal barlows are good, especially for the money.

I would like a Tal but apparently they have been ordered to concentrate their efforts towards the requirements of the Russian military for the time being and so new barlows for the UK market will be delayed! What exactly the Russian military want to look at so badly, I couldn't speculate...

Tom

[Merlin66]

The KLEE barlows (University Optics ) were designed for fast Newt's, they come in x2.2 or x2.8 well worth looking for.

I used them on 13" and 18" f4.5 scopes for a while ( and the associated PRETORIA 28mm eyepiece - majic!!)

The Klee is much better IMHO tham may of the alternatives.

[tom714uk]

That's interesting about the Klees, I'll look out for them. Thanks.

Sent from my HTC Desire S using Tapatalk

[crazyjedi]

I'm interested to know - what is the best barlow for my money?

[Gina]

Now there's a BIG question! It's something everyone wonders and like everything else depends on what sort of price range you can afford and your specifications. Generally speaking, as usual, the more you pay the better you get.

If you could be more specific in what you are prepared to pay and what sort of use you want it for (eg. planetary, lunar, DSO) I think you might get some replies. ATM it's such an open ended question that nobody feels able to answer it.

[newman]

You want to avoid too cheap barlows because they won't produce satisfactory results in any scope. As for the relationship with a fast scope and a barlow, using one (a good one) can actually improve the performance of an eyepiece that is otherwise problematic in your scope due to it being fast, since (for example) a 2x barlow will essentially turn an f5 scope into an f10 - way more tolerant on ep's. Of course, one must be careful not to exceed the limits of his scope coupled with what atmospheric conditions will allow.

[John]

I think the Antares 1.6x 2" barlows are superb bits of kit. They are less "extreme" than other barlows in terms of modifying the light cone and seem to work extremely well in all scope designs. If you can find them, they are also relatively affordable.

[crazyjedi]

Are the celestron ultima barlows any good?? they seem to be mid range in regard to price

[John]

Are the celestron ultima barlows any good?? they seem to be mid range in regard to price

Yes they are very good Rob. I reckon the Ultimas and the Antares 1.6x that I mention above come from the same factory in Japan - they definitely have the same look and feel about them.

The USA company Orion has a barlow called the "Shorty Plus" which is exactly the same as the Celestron Ultima. They sometimes can be had for less than the Celestron versions.

[GazOC]

Be careful though, theres a "Shorty" as well as a "Shorty Plus". The former is best avoided unless you are on a tight budget.

[John]

Be careful though, theres a "Shorty" as well as a "Shorty Plus". The former is best avoided unless you are on a tight budget.

Good point Gaz - definitely go for the SHORTY PLUS

[great_bear]

Funniliy enough, some well-respected folks on CN are fans of the standard shorty!

For myself, I didn't like Barlows at all until I tried the (non-Barlowesque) Tele Vue Powermate.

- would love to play with a Klee one day though...

[jkemal]

I have read that you can get some 2' barlows which you can use with 1.25' eyepieces, how do they work?

[brantuk]

The Televue Powermates are top notch the best imho, and the Antares are extremely good too but a lot cheaper. After that the Orion Shorty Plus and Celestron Ultima together - then the Tals which are great vfm.

The Tal/Orion/Celestron are all 1.25" (at least I've not seen 2" versions of them). The Antares 1.6 that I have is 2" and the Powermate 2" comes with a 1.25" adaptor to take both sizes.

[michael.h.f.wilkinson]

I have two Meade Series 5000 TeleXtenders (2x and 3x) mainly used for planetary photography. The have similar properties to the TV PowerMates, and work very well on my F/6 scope.

[great_bear]

I have two Meade Series 5000 TeleXtenders (2x and 3x) mainly used for planetary photography.

- and (rather curiously) these seem to be only available these days under the Bresser brand and the price - stranger still - depends on the magnification! - I've been meaning to try the 5x for a while - but not at that price...

[michael.h.f.wilkinson]

- and (rather curiously) these seem to be only available these days under the Bresser brand and the price - stranger still - depends on the magnification! - I've been meaning to try the 5x for a while - but not at that price...

I had noticed that as well. I am now looking to get the 2.5x PowerMate, because F/20 is sometimes to small, but F/30 is too much.