SvBony 3x Achromatic Barlow

[Nightspore]

 

After failing to split Epsilon Boötis (Izar) with my ST80 and Celestron Zoom recently I decided I needed more power in the form of a 3x Barlow.

 

 

The bog-standard 2x GSO achro' was fine, but it only gives me 100x at 8mm.

 

 

My TV 3x, which I've owned for many years, is great but has a long barrel. Even with an adapter I worry about the Barlow cell making contact with the mirror in a 2" dielectric. So I ordered this inexpensive SvBony Barlow for £22.99. Principally as it would be delivered the next day, well that and it was relatively cheap. I soon discovered it broke down into three separate pieces. It's incredibly light, barely 90 grams. I'm fairly convinced the main housing is made of some form of polymer material and not a light metal. Which might explain the weight (or lack of it). The inside of the housing is not painted matte black however. SvBony claim the Barlow cell itself is edge blacked.

 

 

The Barlow lens is coated but it's not obvious to see. The end dust caps are OK but seem a little cheap. The short barrel appears to be a chromed brass standard type. The Barlow cell resembles a GSO but I doubt it is. Although having said that the faint green coatings visible on the SvBony do resemble GSO's basic coatings. It features a compression ring and a plain brass thumb screw.

 

 

They say the proof of the pudding is in the eating. I didn't actually eat the Barlow but I gave it a whirl on Sunday night. 'Telescopius' stated that the cloud cover was going to be good (30%) but the seeing would be fairly crappius at 40%! So at 21:00 BST I opted for the ST80 over the 60 EDF as the extra 20mm can help for rich field viewing in bad conditions. The overall transparency wasn't particularly good either. I had a bit of a rich field sweep at 13x with a 30mm GSO SuperView, then swapped it for the SvBony 3x and Celestron Zoom. The first doubles I split were a low Almach, then Cor Caroli, Algieba and Achird. The Barlow gave sharp images with good colour separation. I saw no evidence of ghosting or any aberrations. Finally I got Izar in the finder. The zoom was at 8mm (150x) and the split was definite. I found that I could even go down to about 125x and still split the two components of ε Boo. So I'm a happy bunny. Not bad for 23 quid.

 

Edited April 12, 2021 by Nightspore