10x41

[Starlight 1]

Was looking for a pair of bins and I see a pair of S/H 10x41 in the canera shop,

He said price new was £150 and I can have this pair for £85.

So are 10x41 any good or do I look round for something better like 10x50 for looking at the night sky only.

Is individual eyepiece focusing good when looking for bins.

[BinocularSky]

Depends on the quality of the binocular. Very many lower priced 10x50 binoculars (e.g the Bressers that Lidl do) are internally stopped down to around 10x40 anyway.

IF is good for astronomy, where you don't need to refocus, but not so good for other uses (e.g. birds or the gee-gees) where you may need to refocus continually.

[Mr Q]

More important is the question "Do they have "fully coated optics"? This means every surface of every optical part is coated to reduce light scattering (increasing contrast) and optimizing light transfere through the glass (increasinf light gathering power).

The bins you choose for astronomy use should have fully coated optics and the best prisms - hold the bins a few inches from your eyes and point the bins at a bright object (the daytime sky). If the bright spot of light appearing in the middle of the EPs has squared sides, the bins have high quality prisms - what you want.

As far as size/mag. power, 10x50s for hand held use and 15-20 (range) x 70 for mounted use will work nice.

If you can't confirm the bins have fully coated optics and good quality prisms, don't bother with them for astronomy use.

[BinocularSky]

More important is the question "Do they have "fully coated optics"?

Not really, no. "Fully coated optics" are desirable, but they cannot compensate for shoddy optical or mechanical quality.

hold the bins a few inches from your eyes and point the bins at a bright object (the daytime sky). If the bright spot of light appearing in the middle of the EPs has squared sides, the bins have high quality prisms - what you want.

Sorry to contradict, but no again. If the exit pupil has squared sides, the prisms are undersized.

I discuss both of these things at further length, with images, here.