which bins and why

[rowan46]

I am not so interested in magnification but am interested in more apparture and good optics. Presently I am using pentax xcf 10x50 not the best optics in the world but good enough to do the job and make me want more. The maximum step up I can afford is in the £230ish region these get half decent reports for different reasons which would you choose and why or are their better?

First Light Optics - Barr & Stroud Savannah ED 56mm

First Light Optics - Pentax 20x60 PCF WP II

thankyou

[E621Keith]

I will go for the Pentax. It's a porro, has larger aperture and has field flattener lens in the eyepiece. It's a proven astro binocular and Pentax is a better brand, which means it will hold its resale value better.

Good alternative would be a Kumming BA8, such as this William Optics 10x50

First Light Optics - William Optics 10x50 & 7x50 ED Binocular

[BinocularSky]

I concur with what Keith has said. All else being equal, you will always get better optics for your lucre with a Porro than with a roof -- a roof-prism has to be made approx 300 times more precisely than a Porro prism, which is why they cost more.

I also like the Kunming BA8 -- I have the 15x70 version of it and rate it very highly indeed. In fact, if you are patient, used BA8 15x70s come up occasionally on ABS

within your price limit -- look out for brands like "Helios Apollo", Garrett Signature", "AstroPhysics", "TS Marine", "General Hi-T", "Oberwerk Ultra" -- all the same thing. Mine is now my most-used binocular. Needs to be mounted (but then, so would the Pentax you mentioned).