Pros and Cons of 2" Barlows

[MikeP]

At present I have a "no name" 2x barlow and a 3x Tal barlow. I've started thinking about buying a better quality one, since I have just bought a good quality 2" diagonal.

Some of the barlows I have looked at are available with 2" barrels. I only have one 2" eyepiece and I don't normally want to barlow it, but it did get me thinking and I have two questions:

Assume whatever I buy will be used for visual and imaging and ignore price as an issue.

• 
  [li]What are the pros and cons of buying a 2" barlow rather than a 1.25"?[/li]
  [li]At present, I have the Meade 5000 Super Plossl set. If I replace those eyepieces with ones that provide a wider FOV, does that make any difference?[/li]
  

Thanks for your help.

Mike

PS I am leaning towards a TeleVue Powermate. Does that make any difference?

[John]

I can't answer all your questions as I have not tried a 2 inch barlow. I use a Celestron Ultima 2x barlow which I have found to be very good indeed (it's actually more like 2.2x I believe).

With regards to wide angle eyepieces, I barlow my Tele Vue Naglers and that works extremely well - you get the power increase and retain the eye relief and the very wide field of view.

If you can run to a Tele Vue Powermate then you will not be dissapointed (in either the 2 inch or 1.25 inch size). I believe that they are simply the best "amplifying lens" (Tele Vue prefer that term to barlow) around.

Personally, if you do not wish to use it with 2 inch eyepieces, I can't see any reason to buy a 2 inch barlow - someone will probably now provide me with a good reason of course

John

[dogfish]

Hi Mike

I'm thinking about a 2" barlow too after I recently purchased one of these:

http://astronomica.co.uk/Mirrordiagonals.php?product=50&action=moreinfo&offset=0

and one of these:

http://astronomica.co.uk/SuperWideAngle.php?product=384&action=moreinfo&offset=0

I was pretty impressed with the SWA EP; so much so that I thought I might buy a couple more, hence I'm thinking of a 2" barlow to get a wider range of magnifications. I bought the diagonal and EP from Astronomica's stall at the recent Stirling astro soc shindig and whilst I was there I had a play with their own brand barlow. Seemed pretty well made for the price. The specs are here:

http://astronomica.co.uk/BarlowLenses.php?product=251&action=moreinfo&offset=0

HTH, Martin

[Macavity]

Of course one has to watch that not ALL 2" Barlows fit into star diagonals. (Doh!) One that I had, that does, and I now miss, is the 2" Antares 1.6x. A very useful value, will accommodate (and fill "gaps" in) the Hyperion series. Nice quality Japanese optics too.

http://www.scopesnskies.com/prod/50.html

[Beyond_Vision]

The obvious point is that you can use both 1.25" and 2" eyepieces in a 2" barlow but you cant use 2" eyepieces in a 1.25" barlow. So you may as well stretch to a 2" barlow which will future proof you.

Regards

Kevin

[mightymonoped]

Some Barlows also have uses in addition to their amplification. I have used my Televue Barlow without the actual lens, it effectively becomes an extension tube, allowing focus for imaging without the need for a diagonal. This could also apply to 2" Barlows too (assuming they include a 1.25" adaptor).

Tony