Swift Osprey specifications

[Robert Ellis]

I am looking at a pair of these 7.5x42 Ospreys on eBay. Does anyone recollect some of the more major specs for instance eye-relief, close focus, and weight? I am drawn to them as a dual-purpose binocular, pelagic birding and astronomy, with some other birding tossed in just because they look smashing.

[solentbirder]

I owned a pair of these as my primary binoculars for several years. The ergonomics are very good. Eye relief is pretty good but the apparent field of view is quite narrow so it's a bit like looking down a tunnel. Having said that it's a very comfortable binocular to use. Not as bright or contrasty as modern binos because they aren't multi-coated. Instead they have the 'Swift amber coating'. The prisms are Bk7 glass not BaK4. I think the actual field of view was 367ft at 1000yds. A nice instrument but won't stand direct comparison with modern mid-range binoculars.

[henry link]

Swift specs say weight 29.5 oz., eye relief 19mm, close focus 16 ft., field width agrees with solenbirder, but Swift claims the prism material (at least in the mark II version) is "the new BPG-2....which gives this binocular the eyes of a hawk." I expect solenbirder's description is closer to the truth.

[chartwell99]

Swift specs say weight 29.5 oz., eye relief 19mm, close focus 16 ft., field width agrees with solenbirder, but Swift claims the prism material (at least in the mark II version) is "the new BPG-2....which gives this binocular the eyes of a hawk." I expect solenbirder's description is closer to the truth.

Surprising that the prism glass would be BK7. I have a Swift Mark II 7 x 35 Neptune from the mid=60's, a near perfect clone of the Bausch & Lomb Zephyr of the same era, which plainly employs BAK4 glass, and I understand that the Swift Audubons from the very beginning have also used BAK4 prisms. I had assumed that it was only the Swift Aerolites which cheaped out, as their prices so reflected.

[solentbirder]

Surprising that the prism glass would be BK7. I have a Swift Mark II 7 x 35 Neptune from the mid=60's, a near perfect clone of the Bausch & Lomb Zephyr of the same era, which plainly employs BAK4 glass, and I understand that the Swift Audubons from the very beginning have also used BAK4 prisms. I had assumed that it was only the Swift Aerolites which cheaped out, as their prices so reflected.

It's definitely not BAK4 (at least not in the pair I owned) since the exit pupils clearly had the typical square shading at the edges from lower grade glass. I've got an old Swift 7x50 Neptune MkI and that's got Bk7 too.