Antares X2 Barlow

[Naz]

Some of you may remember the unfortunate sequence of events when I purchased this last year from

SnS Putting that aside, I have used this item on many occasions since, or should I say, tried to use it.

Last night I set the 200mm Revelation up and switched the fan on, after an hour I started to have a look at :jupiter: starting with a SW 10mm plossl, fairly good views, with some turbulence, but getting fairly good glimpses of the belts and and some hint of finer detail from time to time.

Switched to the Vixen 6mm plossl, and the turbulence was more of a nuisance, but still good glimpses again of the belts and detail.

I then inserted the barlow and could not get any focus, the image looked as though it was close to focus, but no detail. Went back to the 10 mm with the barlow and got the same result.

I have tried this barlow on the 120ST and the Evostar with the same results, just cannot get focus, it's as if I was trying to exceed the scopes capability.

Just in case any of you query it, on the 200mm Revelation, 1200mm fl X 2=2400mm divided by 6mm = X400, the usual accepted maximum for this size scope.

On the 120 ST, 600 X 2 = 1200 divided by 6mm = 200,X just below the max!

On the Evostar using lower power eps brings similar results, although I would exceed it's capabilities with the 6mm and push my luck with the 10mm.

Overall, my impressions are not favourable, but will persevere and hope that it will work when the seeing is better.

Impressions are not favourable at present, maybe will have to save up and get a better quality barlow, this has been an expensive way to buy an adaptor

naz

[lunator]

Naz

Is this the 3 element Apo barlow?

I have this one and its ok with my scopes.

If you were looking at Jupiter low down then pushing the magnification to the scopes max will lead to image breakdown as the seeing just won't support it.

Just out of interest point the scope at the double double when it is near zenith. If you can't split them using the barlow there is an issue

Cheers

ian

[Naz]

No Ian, it's the standard one with the T thread on the end, realise that I might be pushing my luck, mind you from my location here in France, 46 degrees north, :jupiter: is a lot higher than my last location at 59 degrees north last year.

Still willing to see if i can make it work, could be that I am not "settled" yet and am expecting too much from it, but and its a big but, if the 6mm plossl gives me 200X, then the 10mm with the barlow gives me 240X. On an 8 inch scope, I wouldn't have expected such a difference, with the 6mm giving good contrst and hints of finer detail when the atmosphere allows, the 10mm and barlow I would expect to be slighly poorer, because of the slight increase in mag and the extra glass from the barlow, but the difference is greater than what I would have expected.

Will follow your suggestion and try it on doubles and open clusters near to my zenith and report back.

naz

[Andrew*]

Hi Naz. I think you could possibly be expecting too much from your skies... Certainly a 6mm barlowed will amplify the nasty effects of seeing and you will not be able to see a clear image, regardless of the scope's aperture. For where I live the seeing won't allow a magnification of more than 250x on an average night, even though the scope's theoretical limit is as you say 400x.

Also consider the extra glass you're putting in the light path...

HTH explain a bit

Andrew

[centroid]

I think its fair to say that Antares gear is at the budget end of the scale, as such probably no better or worse, than Celestron or Meade's standard Barlow offerings.

If you want to try a really bad Barlow, then it has to be the Skywatcher offering, as supplied with several of their scopes, along with equally as bad eyepieces. I experienced these 'first hand', when I bought an ST80 to use as 'guide scope' (now replaced with an ED80).

I used a standard Celestron x2 Barlow for some time, but upgraded the Ultima, which is in 'different league' altogether. Also have a TeleVue x5 PowerMate, which replaced my AE x4 Image Mate, again major upgrade.

The 'bottom line' is you get what you pay for, and in this respect Antares are probably reasonable value for money. However, one good quality eyepiece is better than a whole set of cheap ones.

If I were to recommend a quality Barlow, that's reasonably priced, it would have to be the Celestron Ultima.

Dave

[Naz]

Quick update on my exploration of this barlow, although it is a "budget" device, I still would expect to be able to achieve focus, or a point where it was looking as though it would be about there. Allowing for atmospherics and the fact that my scopes are not APO and the ep's are the standard plossl's, I believe that there is a point even at lower mags where focus should appear to be achieved.

Tonight I have clear skies and a steady atmosphere, so I decided to give it another try, this time using the 120ST only, as this was the scope that I bought the barlow to be used with. I set the scope up, and after 1 hour, which should be plenty of cool down time, even though I keep the scopes in an out building, I focused in on :jupiter: with the 25mm, aok, moved on to the 10mm, also sharp with some of the fainter bands showing in moments of clarity. Moved up the 6mm, not good, The darker belts showed just, fainter detail did not show.

Went back to the 10mm plossl everything as before, tantalising details flickering through. decided to try the barlow. Put the barlow in, and yes the belts showed, hints of the finer detail appeared to show promise, but didn't deliver. tried the 6mm with the barlow, pants! Without the barlow, slightly better than the 10mm + barlow.

Previous use had not even allowed the Jovian moons to appear sharply focused, tonight it did.

In conclusion, possibly I was expecting too much, and after trying on many occasions previously, I was beginning whether this would deliver!!

Well it can, but because of the limitations of its design / build /whatever (!) I suppose it requires fairly good conditions to deliver a result that doesn't disappoint, or perfect conditions to please

[lunator]

Naz

I think you have hit the nail on the head.

If the 6mm will not show a good image then conditions are not good for observing and the barlow will not improve this.

If you really want to test the quality you need to look at an object at zenith as this minimises atmospheric interference.

Cheers

Ian

[AstroTiger]

i also bought the same barlow.

To be fair it seems to work fine for me though i have not used it for any deep sky work as yet. Many for PST. But it has helped.

The peeps are right though, Antares is the make do brand i think, its functional, does the job. But its not top end spec, hence the prices!

AT

[russ]

It's sound more like the skies weren't upto it really. Do you have a 20mm you can barlow? Direct comparison between the 10mm unbarlowed and 20mm barlowed. That way you are not pushing the scopes or the skies and can just see if the two compare.

From personal experience, 400x is really pushing it regardless of scope. May get one night a year that is so good it can take those sort of mags. And my ST120 couldn't get close to a decent image at anything above 150x regardless of the night. So perhaps 200x is asking a bit much of the ST120. Just clutching at straws here. But definitely compare a barlowed lower power eyepiece with the 10mm unbarlowed.

Russ

[Naz]

Thanks for all the comments folks, I am aware of the optical problems of introducing extra elements into a light path, just didn't appreciate how much atmospherics played. I had expected to see a more defined focus, but not the finer detail. I know I was pushing the 120ST but was just wanting to see what I could achieve. The 120ST is great for wide field sweeps and performs well with lower powers. (was tempted by your 120 Rus and mounting the two as a bino 8) but funds are tight, or so I am told)

Will wait and pray for steady seeing and give the barlow another go and report back.

Thanks again all.

naz

[AstroTiger]

please note, i have found the barlow lense can be a bit of a b****r to screw into the end of an eyepiece.

Plus i dropped it on concrete the other weekend. seem to work fine after.

Some more useless info for u,

hope this helps

[Naz]

It's been a while since I attempted to use this barlow after the first few attempts disappointed, and as promised, I said I would try it out when conditions improved.

Saturday evening was clear here, with good steady seeing, so I had the ST120 on the EQ5 and cruising the Moon, as one does on a Saturday night

Things were very steady in the 6mm Vixen plossl, so banged in the barlow. This took the magnification up to 200 X. Moved along the terminator, everything was a sharp as I expected. Very little colour, (I have a Baader Fringe killer fitted), no more than was visable with the Vixen on it's own, so it just proves that I should try to be more patient when observing and allow for conditions.

My first try was obviously tarnished by the unfortunate experience I had when purchasing the barlow, (enough said).

As a budget optic, fine for the occasional observation, and most beginners would probably be satisfied with the performance.

naz