I make an exception to my view of TeleVue® when it comes to Barlows. A Barlow not only only serves to magnify the 'X-Factor' of an eyepiece, but also magnifies any optical imperfections inherent in the entire optical-train. And this also includes the Barlow itself. As a result, I do suggest paying the difference (not that much, really) towards a top-of-the-line Barlow - such as a TeleVue® 2X or 3X Barlow.

There are other top-drawer Barlows out there, new & used. But I'm really only a position to speak of that which I own - TV's. At least for Barlows, as well as a 2.5X PowerMate (which are fully a different animal altogether - best for a discussion of it's own).

Buying mid-range Barlows usually ends two ways: Hating Barlows forever, or buying & selling more and more mid-range models until you finally buy a TeleVue®. Or equivalent one.*

Caveat Emptor,

Dave

* - I'll let others chime in to give their choices of excellent glasses.

 

When I bought a used ST-80 to balance out the relatively limited field of view of my Mak, the owner included a whole bunch of stuff with it, including about half a dozen eyepieces and an Orion Ultrascopic Barlow. This is a long-format Barlow - as opposed to the shorty Barlows that seem so prominent nowadays - and is made in Japan. I don't have much Barlow experience, except for using one 35 years ago and being sorely disappointed, like Dave said. My guess is that it was a single-element Barlow back then. My other guess is that, not having any idea about maximum magnification, I was probably trying to Barlow my eyepieces to get well above 300 or 400x.

This Ultrascopic really rocks the house. Because I had this Barlow, I specifically bought a 12.5mm Ortho that gives me 123x through my Mak. I did this to preserve the relatively longer eye relief that a longer focal length Ortho has. The 12.5mm Ortho has 10mm of eye relief, which is plenty. I also got it because I knew I could Barlow it to get 246x without losing any of that eye relief. The Ultrascopic really does the trick nicely in this regard.

 

That's very much something I tend to touch on regards previous Barlow experience. Back in the Stone-Age I had a cheapie Barlow from Edmund Scientific that came with my new (In 1972) 3" Edscorp Equatorial refractor. And this "Barlow" was the worst piece of glass I'd ever seen!

It wasn't mounted in it's tube in any sort of workable way. It was supposed to be slid up & down to change it's power - or so said the "instructions" - which needed someone with a Rosetta Stone to decipher! Even if you had such, there was no-way it would present a correct focus. I did two things: 1. - Swear I'd never go near a Barlow ever again! 2.- Give it to my Cat to play with. It gave me a thrill every time ol' Casey batted the rotten thing around the house! At least someone was having fun with that hideous thing!

Perhaps such explains why I suggest people to start at the top-of-the line Barlows, such as the TeleVue® 2X and 3X. Or the several other high-end offerings people have suggested in the past.

I must admit my ignorance of these Ultrascopics Barlows. But if they can maintain the sharp and clear image from an orthoscopic EP - it must be one of the worthy contenders! Would you be able to take a picture of it? Preferably from several angles - side, nose-end, and bottom-end? I'd love to toss same into my Barlow Files I maintain to hand off to folks who are interested.

Anywho, thanks for the useful posting(s)! I'm sure it will serve as a reprieve to another out there who has sworn off Barlows for life and, just perhaps, try again with better stuff.

Keep clawing that piece-of junk-in Cat-Heaven, Casey!

Dave

 

I'm not so hot with all this "taking pictures and transferring them to the web" stuff. But here's a pic from these intertubes thingies

http://www.telescopehouse.com/media...3525d08d6e5fb8d27136e95/U/L/ULTRASCOPIC_2.jpg

http://www.cloudynights.com/uploads/monthly_02_2016/classifieds-40244-0-32313200-1455299828.jpeg