Advice on which Barlow to upgrade to.

[Danny83uk]

Hi all, Im currently using Celestron 2x Universal for my imaging but would like to tighten up the quality now ive got to grips with exposure times,ISO  and stacking. My usual stockists have 2 different variants and just gathering opinions.

They are BST Starguider 1.25 Short 2x and Celestron X-Cel Barlow Is there a better one over the other? I'll probably be getting the 3x of the same model at a later date or at christmas if ive been a good boy. Also would 5x Meade Series 5000 TeleXtender be difficult to use  for planetry photography?

Thanks

Danny

[John]

If you can get a used Tele Vue Powermate 2.5x then you won't need to upgrade again.

They can be had for around £120 on UK Astro Buy & Sell.

A less expensive but similarly excellent alternative is the Explore Scientific 2x Focal Extender.

Either would be a noticable step up over your current barlow wheras I suspect the others you mention might not be such a noticable improvement ?

 

[SkyBound]

There is a brand new Televue 2x Barlow on ABS at the moment, good price too, I have one and they are superb quality...

[Dave In Vermont]

I've said it before, but it bears repeating: The best Barlow is one that is invisible in the optical-pathway. This means that it lends no internal reflections, no distortions. It simply adds magnification to the view. There's nothing worse than a Barlow which imparts, and magnifies, it's own short-comings in the glass itself.

I'll 2nd. John's suggestion of a TeleVue® 2.5X PowerMate, or any other TV Barlow. There are other top-end Barlow's made, but the TeleVue® are the one's I have and use. And though TV is known to be the most expensive products out there, they really aren't that much more £££'s - considering that it will be the last one you'll ever buy. You can't go up from the top.

Dave

[Putaendo Patrick]

Another contender might be a second-hand Celestron Ultima x2 Barlow, now out of production. Not as good as Televue - but quite close for less money and possibly the best Barlow made/marketed by Celestron. I've heard it is the same as the Orion Shorty Plus, so perhaps another second-hand alternative.

[Ruud]

Maybe you'll find this discussion useful: http://www.cloudynights.com/topic/487812-praise-for-the-3x-tv-barlow/ 

The OP ranks the best brands and types he knows. The top 10 is claimed by Vernonscope, Siebert , Televue and Explore Scientific.

[Danny83uk]

20 hours ago, John said:

If you can get a used Tele Vue Powermate 2.5x then you won't need to upgrade again.

They can be had for around £120 on UK Astro Buy & Sell.

A less expensive but similarly excellent alternative is the Explore Scientific 2x Focal Extender.

Either would be a noticable step up over your current barlow wheras I suspect the others you mention might not be such a noticable improvement ?

 

Please excuse my ignorance but why the 2.5x over a 2x and 3x seperately to give you more focusing options (expense being one obviously) Is This the one you mean?

18 hours ago, Dave In Vermont said:

I've said it before, but it bears repeating: The best Barlow is one that is invisible in the optical-pathway. This means that it lends no internal reflections, no distortions. It simply adds magnification to the view. There's nothing worse than a Barlow which imparts, and magnifies, it's own short-comings in the glass itself.

I'll 2nd. John's suggestion of a TeleVue® 2.5X PowerMate, or any other TV Barlow. There are other top-end Barlow's made, but the TeleVue® are the one's I have and use. And though TV is known to be the most expensive products out there, they really aren't that much more £££'s - considering that it will be the last one you'll ever buy. You can't go up from the top.

Dave

Same question really on the 2.5 over 2,3x. I like the idea of its the last one ill buy.

 

Any opinions on the 5x?

[Dave In Vermont]

The TV PowerMates are not a 'true' Barlow, but a different design - technically speaking. They provide an excellent view, as do the TV Barlows of 2X and 3X. I realize the first impulse of new astronomy fans is to throw extreme magnification in hopes of getting views like the Hubble Space Telescope. But for most applications, using 5X will not be practical due to mitigating factors - like 'seeing' conditions. Remember - you'd be magnifying everything by a factor of 5X. Including atmospheric disturbances. You'd be better off trying a shorter focal-length eyepiece.

If you buy a top-drawer Barlow, I think you'd get much more mileage for your money with a 2X or 3X Barlow, or a 2.5X PowerMate.

Best wishes,

Dave

[ghostdance]

Another vote for the Power mate (and indeed the 2x TV Barlow). As Dave said, they just disappear in use. I also have the well-regarded Orion Shorty Plus 2x ( useful in not adding too much weight/length to my small scopes) but it has never seemed *quite* as invisible as the Tele Vues - tho this is utterly subjective as I've never directly compared them at the eyepiece on the same night, so seeing etc could be a factor!

Agree with John tho - I'll never sell the Power mate unless something substantial is at stake

[Mak the Night]

Although I consider the TV 3x Barlow probably the best of its kind, if you need a shorter 3x the Celestron X-Cel is excellent quality.

[Danny83uk]

48 minutes ago, Dave In Vermont said:

The TV PowerMates are not a 'true' Barlow, but a different design - technically speaking. They provide an excellent view, as do the TV Barlows of 2X and 3X. I realize the first impulse of new astronomy fans is to throw extreme magnification in hopes of getting views like the Hubble Space Telescope. But for most applications, using 5X will not be practical due to mitigating factors - like 'seeing' conditions. Remember - you'd be magnifying everything by a factor of 5X. Including atmospheric disturbances. You'd be better off trying a shorter focal-length eyepiece.

If you buy a top-drawer Barlow, I think you'd get much more mileage for your money with a 2X or 3X Barlow, or a 2.5X PowerMate.

Best wishes,

Dave

Not to mension the problems keeping the object in focus and view. It would be used for imaging but I was moving away from it for that reason originally but just needed to clarify. Could you elaborate more on its difference? Does this difference make it more suitable for imaging over viewing?

 

[John]

7 minutes ago, Danny83uk said:

Not to mension the problems keeping the object in focus and view. It would be used for imaging but I was moving away from it for that reason originally but just needed to clarify. Could you elaborate more on its difference? Does this difference make it more suitable for imaging over viewing?

 

I've found that Powermates work excellently for visual observing. They literally "get out of the way" leaving just the amplified magnification without the optical effects that a barlow (even an excellent one) adds in terms of changing the focus point, extending the eye relief and sometimes vignetting the field.

I'm not an imager myself but I know that Powermates are very popular with imagers as well.

 

[Danny83uk]

1 hour ago, Mak the Night said:

Although I consider the TV 3x Barlow probably the best of its kind, if you need a shorter 3x the Celestron X-Cel is excellent quality.

How do you think the longer Barlow would cope with a 409g dslr body attached to it? It is a relatively light body, which is why I picked it. But curious. 

[Mak the Night]

1 hour ago, Danny83uk said:

How do you think the longer Barlow would cope with a 409g dslr body attached to it? It is a relatively light body, which is why I picked it. But curious. 

The TV 3x is 13cm tall and weighs about 181 grammes. The taller the Barlow the more potential for it to rotate the diagonal.

[Charic]

I don't image but for my needs I have the  Sky-watcher 2x deluxe, because it had an adapter/extension for dslr use and removable cell,   if/when needed and I keep forgetting  the Meade #140 2x Apochromatic Barlow Lens, so need to refresh my memory and test that again when the weather improves?
I hear so many folk praise the Powermate ( never had the chance to try one) but as john so rightly points out, quite often when one 'upgrades'  there "might not be such a noticable improvement ?"[sic] to what you already have.
By testing yourself, only you can tell if one is better than another. You have the option to return goods if you order online, keep returning until you find what suits you best?

[Dave In Vermont]

One trick I use for weight-loads that can cause things to rotate or slip, where the interface is a soft-alloy and a brass-ring such as is found on compression-bands for telescope parts, adapters, etc. - is to roughen the surface the softer brass will be trying to hold in place. It may seem similar to desecrating a religiious-icon (or TeleVue® Barlow), but by using a very hard file - file away on the alloy-barrel of the Barlow (in this case) to create pits & valleys for the compression-ring to bite into firmly.

I have a poorly designed alt.az-mount that was supposed to hold 10lbs. But wouldn't even hold 2lbs. So the outfit selling these dropped the price by 2/3rds. I used the above method to 'repair' it. Now it holds better than 10lbs.

Call it physics?

Dave

[Danny83uk]

On 15/11/2016 at 04:28, Dave In Vermont said:

One trick I use for weight-loads that can cause things to rotate or slip, where the interface is a soft-alloy and a brass-ring such as is found on compression-bands for telescope parts, adapters, etc. - is to roughen the surface the softer brass will be trying to hold in place. It may seem similar to desecrating a religiious-icon (or TeleVue® Barlow), but by using a very hard file - file away on the alloy-barrel of the Barlow (in this case) to create pits & valleys for the compression-ring to bite into firmly.

I have a poorly designed alt.az-mount that was supposed to hold 10lbs. But wouldn't even hold 2lbs. So the outfit selling these dropped the price by 2/3rds. I used the above method to 'repair' it. Now it holds better than 10lbs.

Call it physics?

Dave

I dont think ill be willing to do that. but i see where your going. Im more inclined to rotate my scope so its either hanging directly down or pointing up to remove any bend in the optics.