Barlow or Powermate ? Which is better

[Alan_B]

What is the difference between a Powermate and a Barlow ?

I'm guessing that the Powermate is more suited to photographic use but what advantages are to be had by using a Powermate as opposed to say a Celestron Ultima barlow

[Stephen]

Typically adding glass to the train deteriorates (either a little or a lot!) the end image.

A Powermate has zero deterioration (to my eye.) That's why they cost so much

[newman]

In addition to being of superb quality typically found in TV stuff, it's a telecentric design. Regular barlows have an impact on eye relief, making it a bit longer (only really problematic on longer focal length eyepieces, can lead to kidney beaning / blackouts, etc), and typically switching from eyepiece to eyepiece + barlow requires a refocus. A powermate, on the other hand, doesn't mess with eye relief and it remains parfocal with an eyepiece, so you shouldn't require a refocus - and even if you do, it should be a very slight adjustment.

Powermates of course cost more than most barlows, but considering that this paricular piece of kit is going to be used with several eyepieces, and probably quite a lot, I don't think the price is outrageous.

[swamp thing]

A Powermate or Barlow will be in your eyepiece case for life.

You may change eyepieces but you are unlikely to change a Barlow.

So IMO buy a life tool, buy the very best

My 2"x2 Powermate, I will never sell its the best thing in my eyepiece case. It will work with any scope, any imaging rig simply a great tool.

Regards Steve

[kev]

When you have used barlows, and have used powermates....

you will wonder why you ever bought a barlow.

Quality is so much better, CA is better, and because of the design the effect of it on your eyepeices after it is minimal.

[Damo636]

Another vote for the PM. To my eyes completely invisible in the optical train.

[Mr Moff]

Oh no,not another item to add to the wish list.I knew I shouldn't have clicked on this thread.

Danny.

[petek314]

I have a 3x and 2x Barlow and a 5x TV powermate. I think the image quality with the Powermate beats the barlows. I bought my scope to observe deep sky objects but the Powermate allows me some decent planetary observing.

[Alma]

I still wouldn't completely trash really good barlows in comparison with a Powermate though. I used to have a Celstron Ultima and actually preferred it to the 2.5x Powermate. It was more a question of size and usability rather than optical quality as I tended to find the Powermate a little tall and cumbersome compared with the very compact Ultima (which by the way is excellent optically). I now use an Astrophysics 1.7x Barcon, which is a superb barlow.

[Sp@ce_d]

All I will add here is that I have a powermate and barlows.. the barlows I only use for extensions minus the glass..

[John]

The only barlow I've used which could match a Powermate was the Antares 2" 1.6x which was superb optically. It still exhibited the barlow traits of extending the eye relief and moving the focus point slightly though, which the Powermate's don't do.

[Mr Bond]

My 2.5xPowermate is tall and much heavier than the simple 2x Barlow I used before.

It doesn't bother me a bit but might be a factor in balancing your scope.

I love mine, and sold my Barlow. The Powermate has that silky TV quality in every way, including optical.

It is handy at 2.5x too, as it makes sense in my EP box ( 32/20/10/6/3.5mm foc length). Some might have planned their EP focal lengths around a 2x. Just a thought.

[Mr Moff]

Will a powermate attach to a T piece on a DSLR?

[Cornelius Varley]

Will a powermate attach to a T piece on a DSLR?

I think they all do now. My 2" 2x has an adaptor which screws into the nosepiece.

Peter

[Mr Moff]

I think they all do now. My 2" 2x has an adaptor which screws into the nosepiece.

Peter

Thank you kind sir.

[25585]

I am considering a 2x 2 inch Powermate for use with my TV Genesis which is 500mm F5. 

As the main EPs I use with the scope are 55mm Plossl, 35mm Panoptic & 13mm Nagler type 1, would there be any vignetting when using the Pm2 in a 2 inch diagonal?

[John]

I've owned and used the 2" 2x Powermates with a range of eyepieces including the 31mm Nagler and 21mm Ethos and I could not see any vignetting with those. The field stop of the 55mm TV plossl is 46mm in diameter compared with the 31mm Nagler's 42mm so it's possible with that one but somehow I doubt it as long as the diagonal has a large enough aperture (the 2" ones usually do).