60s/70s Swallow 10x50 zcf Bino's??

[Chris]

I decided to take a punt on some bino's on Ebay and won the bid at 7 pounds and 5 postage, I've googled Swallow bino's and not much comes up, all I know is that ZSF stands for Zeiss Centre Focussing, I don't know much else about them, coatings? quality of the prism? etc Does anyone know anything about these? although I won't be losing much if the're pants they have got my curiosity going:D

Thanks

Chris

[Chris]

I've done a bit more research and I'm fairly sure they're Japanese.

[michael.h.f.wilkinson]

For 12 quid you can hardly go wrong, can you. Let us know how you fare.

[Chris]

I'll post a review taking into account their age, they've been despatced already and the guy only lives about 40 miles away so they might not take too long to arrive

[Chris]

My bin's arrived a couple of days ago and I've had a bit of a play with them, they seem to be in good condition both aesthetically and optically, I looked through the exit pupils at arms length and saw a diamond shape formed by light grey edges which I've read could be BAK7 prisms. The coatings look fairly good, I can tell the coatings are a tiny bit blotchy if I look closely enough but you have to look very close to see anything other than clear optics. The hinge has a good range of angles and all moving parts including the hinge, focuser, and dioptre have a smooth but stiff action which might help with keeping focus once found. They are surprisingly light I did expect them to be heavier for old bins.

There were some clear spells last night about 11:15pm so I got to test them out a bit before I hit the sack. Focussing on Vega showed little in the way of chromatic aberration, once the Moons up I'll have a better idea about the levels of CA, I moved Vega left to right to check the quality of the field of view which was fairly crisp out to about 5mm from the edge of the FOV. I panned down to the coat hanger asterism which was definately worth a gander as it sat nicely in the FOV. I really enjoy the number of stars these bins reveal, great fun. I've got some Visionary Classic 7x50 on their way so it will be interesting to compare the two.

[michael.h.f.wilkinson]

Sounds like you got yourself some nice bins far a very decent price.

[BinocularSky]

I looked through the exit pupils at arms length and saw a diamond shape formed by light grey edges which I've read could be BAK7 prisms.

<unsufferably picky>

I think you mean BK7. (BaK7 is the Chinese designation for glass with similar properties -- but slightly higher refractive index -- to Schott BaK4; it would not show the grey segments that you saw)

</unsufferably picky>

Glad you like the binoculars; there are some real bargains to be had with some of the old stuff; a lot of it was more likely made to a specification than to a price than is the case with modern budget kit (which seems to trade on catch-phrases like "FMC" and "BaK4 Prisms", as opposed to sound optical and mechanical design and construction).

[Chris]

Sounds like you got yourself some nice bins far a very decent price.

I'm very pleased and count myself lucky as I know Samnatt wasn't quite so with her Ebay purchase.

<unsufferably picky>

I think you mean BK7. (BaK7 is the Chinese designation for glass with similar properties -- but slightly higher refractive index -- to Schott BaK4; it would not show the grey segments that you saw)

</unsufferably picky>

Glad you like the binoculars; there are some real bargains to be had with some of the old stuff; a lot of it was more likely made to a specification than to a price than is the case with modern budget kit (which seems to trade on catch-phrases like "FMC" and "BaK4 Prisms", as opposed to sound optical and mechanical design and construction).

thanks for the correction I have a lot to learn about bins, I've always focussed on telescopes (no pun intended), I meant the prisms that arn't as good as BAK4 but are ok to begin with. This could get addictive I'm already thinking I could make a parallelogram with the left over timber from my obsy build, plus I'll have the tripod spare after I pier mount my HEQ5. I bet aperture fever can easily set in with bins?

[michael.h.f.wilkinson]

P-mounts are great, and I found making mine rather rewarding.