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Which Barlow lens should I buy?


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I’m looking at buying a Barlow lens for my beginner setup which consists of the AstroMaster 130 plus 5mm,12mm and 25mm X-cell eye piece, I have been recommended to buy an Antares x1.5 twist lock. I don’t won’t to spends loads on my beginner setup has I’m saving up for the HEQ5-Pro but any advice on the Barlow lens and also how to use it. 

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5 minutes ago, Ibbo said:

Forget the barlow at the moment .

I would suggest a decent 7 or 9mm eyepiece.

The same make that I have now or a different brand?

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Your scope is a 130 / 650 F5 reflector by the looks of it ??

So your 3 x-cel eyepieces should give you 26x , 54x and 130x

 

You could maybe add the 9mm or 7mm in between your 12 and 5mm lenses, but to be honest, i'd leave it for now

and have a good few sessions with what you have and evaluate things properly.

 

And before you start thinking of busting Jupiter, Saturn and Mars apart with 300x power, remember all 3 planets are

currently pretty low down in the southern sky. So there is a-lot of atmosphere to look through which will distort the image.

Last year i had several sessions with Saturn where i couldn't go much beyond 100x due to atmospherics and poor seeing.

 

More important is decent collimation and giving your scope plenty of time to cool down outside before you use it.

Ideally about an hour, especially if its been stored indoors.

 

So, see how you get on, and let us know how things perform.

Enjoy the views 😀

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Thanks Rob,

 

you are right in saying I should get some sessions in and use the equipment I have already,  this will give me the time too gain more experience on using the equipment. Setting up at home and setting up at different locations is something I’m getting used to at the moment plus this setting up the collimation is something I do need to practice. 
 

I'm over on the east coast for a few days and I’ve brought the scope with me so hopefully the sky’s will clear and I’ll get some practice in. If I do decide to buy a 9mm lens should I stick with the same brand or should I go for better?

 

 

 

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If youreally must have the extra eyepiece I would stick with the same type for the time being.

When I was visual I would use the lower powers for most of my viewing except planets but as Rob says they are very low at the present.

 

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And viewing the 3 of them last evening was pretty typical UK viewing.

Jupiter was so-so : the red spot was there, but the seeing in general was mediocre at best.

Saturn the same, and no real sign of Cassini. I viewed them at 90x which was ok, but when i tried 135x it was a bit too much gas.

Mars has moved quite a way, and was visible low in the east. (When i first spotted it i thought it was a helicopter...😳)

But hopefully in a couple of months it will yield some nice views.

 

 

 

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The family and myself had a few hours looking through the telescope last night and I would say that it proved to be a productive night for logging objects in the night sky. First was the moon with lots of craters visible to see and very clear viewing and I used all the lenses and I’m very pleased with the moon views. The Shimmer from the heatwaves was visible also the wind played its part as well. Jupiter and 4 of its moons was great too see and the two lines visible on Jupiter also visible, Saturn and its rings was great too see also Andromeda was visible.

 

I’m sure the telescopes collimation needs setting up and today I’m going to have a try at collimation myself, with the help from my son. I also need a finder scope to help in locating the objects in the night sky. The rotating of the tube to make Jupiter and Saturn easier to view was the worst of last night’s stargazing experience, maybe I’ve not set the polar alignment and the balance set up correctly.

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12 hours ago, Ibbo said:

If youreally must have the extra eyepiece I would stick with the same type for the time being.

When I was visual I would use the lower powers for most of my viewing except planets but as Rob says they are very low at the present.

 

I don’t think I’ll buy any more lenses for this AstroMaster 130 I’ll save up for the HEQ5 instead.

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  • 5 months later...

Hi all,

 

Back to the Barlow lens folks, I've recently bought a ZWO ASI120mc camera and when we get our next clear night sky i will be setting up and hopefully taking some images of Mars and a few star clusters. I'm looking at now buying either a 2x or a 3x Barlow lens, i've already got a cheap 2x Barlow so i thought i should buy the 3x for now. I have been looking at the Celsestron X-cel and the Explore Scientific Barlow lenses, these are in my price bracket but i would like to hear your thoughts on these two lenses.

 

Thanks...

Paul

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If you are looking for a half decent Barlow then you cannot beat the Antares series.

I have owned a 5x Antares Barlow for years now and the only thing I have found to beat it is the Power mate but that costs 3 times more.

Edited by Graham
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19 minutes ago, Graham said:

If you are looking for a half decent Barlow then you cannot beat the Antares series.

I have owned a 5x Antares Barlow for years now and the only thing I have found to beat it is the Power mate but that costs 3 times more.

Thanks Graham I'll look this one up and see you the price is. thanks 

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The 3x LX is pretty good, although the TV 3x is the best 3x ever made IMO. The LX is probably an apo' and has 20mm clear aperture.

 

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The Baader Q-Turret 2.25x is very good but has a tendency to vignette with anything greater than 10mm. The 2.5x GSO is also very good although in reality it's about 2.2x. Also no provision for a filter thread.

 

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Luminos 2.5x is surprisingly good.

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The Barsta (BST) above is probably the best shorty I've ever used. I've never seen any false colour with it. Mine says 'Omegon' on it so I paid stupid money. FLO have a few in stock.

 

https://www.firstlightoptics.com/bst-starguider-eyepieces/bst-starguider-2x-short-barlow-lens.html

 

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TBH the bog-standard GSO and Synta (probably Barsta) are as good as anything. Not apo's though.

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Thank you very much for passing on your views and photo's regarding my post about barlow lenses. I will be buying the 3x TV barlow lens and i thought i would be paying alot more than £125 this lens is only a few more quid than the two barlow lenses i was first looking at.

 

Thank you all again.

Paul Tomo

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8 hours ago, Paul Tomo said:

Thank you very much for passing on your views and photo's regarding my post about barlow lenses. I will be buying the 3x TV barlow lens and i thought i would be paying alot more than £125 this lens is only a few more quid than the two barlow lenses i was first looking at.

 

Thank you all again.

Paul Tomo

 

You won't regret buying the TV, the optics and build quality are superb. It's also probably best to get a 'long' Barlow anyway if you aren't using it in a diagonal.

 

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Unfortunately I can't convince my TV 2x and 3x Barlows to achieve focus in my 150mm, f/6 GSO Newtonian. TV Powermates will and so does the Vixen 2x Deluxe (below). I believe the Vixen was specifically designed for faster scopes.

 

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FWIW I have the Antares 1.5x TL twistlock. 

 

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It's pretty good, but quite heavy. The filter threads are way oversized (a bit of a glitch on quite a few Antares products). I'm guessing the element has two components. 

 

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3 hours ago, Nightspore said:

 

You won't regret buying the TV, the optics and build quality are superb. It's also probably best to get a 'long' Barlow anyway if you aren't using it in a diagonal.

 

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Unfortunately I can't convince my TV 2x and 3x Barlows to achieve focus in my 150mm, f/6 GSO Newtonian. TV Powermates will and so does the Vixen 2x Deluxe (below). I believe the Vixen was specifically designed for faster scopes.

 

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FWIW I have the Antares 1.5x TL twistlock. 

 

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It's pretty good, but quite heavy. The filter threads are way oversized (a bit of a glitch on quite a few Antares products). I'm guessing the element has two components. 

 

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3 hours ago, Nightspore said:

 

You won't regret buying the TV, the optics and build quality are superb. It's also probably best to get a 'long' Barlow anyway if you aren't using it in a diagonal.

 

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Unfortunately I can't convince my TV 2x and 3x Barlows to achieve focus in my 150mm, f/6 GSO Newtonian. TV Powermates will and so does the Vixen 2x Deluxe (below). I believe the Vixen was specifically designed for faster scopes.

 

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FWIW I have the Antares 1.5x TL twistlock. 

 

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It's pretty good, but quite heavy. The filter threads are way oversized (a bit of a glitch on quite a few Antares products). I'm guessing the element has two components. 

 

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I will be fitting to my Skywatcher 200P and I’m buying the 250PDS later this year so I hope I can get the TV to focus on my scopes.

thanks 

 

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9 minutes ago, Paul Tomo said:

 

I will be fitting to my Skywatcher 200P and I’m buying the 250PDS later this year so I hope I can get the TV to focus on my scopes.

thanks 

 

 

I honestly don't know, although a shorty would almost certainly focus (shorter focal plane). I'm betting the Vixen Deluxe 2x would as well. I think it's a problem on some faster Newtonians although I'm not sure why. I can't remember if it was an in-focus or back-focus problem with my 150mm. Some longer focal length 2" eyepieces won't focus either (including some GSO EP's lol).

 

 

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11 hours ago, Nightspore said:

 

I honestly don't know, although a shorty would almost certainly focus (shorter focal plane). I'm betting the Vixen Deluxe 2x would as well. I think it's a problem on some faster Newtonians although I'm not sure why. I can't remember if it was an in-focus or back-focus problem with my 150mm. Some longer focal length 2" eyepieces won't focus either (including some GSO EP's lol).

 

 

Before I but the TV Barlow lens I will ask RVO or FLO if I will have a problem with focusing. I wonder if anyone else had this problem?

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3 hours ago, Paul Tomo said:

Before I but the TV Barlow lens I will ask RVO or FLO if I will have a problem with focusing. I wonder if anyone else had this problem?

 

It's probably worth asking. AFAIK it's a known problem on faster Newtonians, although refractors aren't immune. Usually a process of trial and error determines what eyepieces will work with a particular scope. I believe Synta has recently taken a centimetre off the length of the most recent 72ED DS Pro models.

 

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Eyepieces shorter than 4mm needed a 1.25" diagonal on mine, which is one of the older versions. There just wasn't enough in-focus otherwise. The 72ED is f/5.8.

 

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Back-focus problems can be ameliorated with longer focuser drawtubes or extension tubes.

 

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In my experience almost all scopes f/6 and faster can have focusing problems.

 

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The back-focus was solved on the ST80 (above) with an extension.

 

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The ST102 (above) had enough back-focus but not enough in-focus until I swapped the Long Perng focuser for a MoonLite.

 

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There have been no problems with the 80ED DS Pro so far with the Long Perng. The 80ED is f/7.5. 

 

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I've never had any problems with my f/7 Altair Starwave.

 

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Edited by Nightspore
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