Old Binoculars

[toetoe]

My father has given me an old set of binocs, no markings at all on them, they are brass and fairly small and not real powerful but they do work well. Is there any way of finding out the power of them as i would like to know if possible.?

[RAJAH235]

Peter, why not try an Optician? May be able to help. L.

[janoskiss]

If you just need a rough estimate then look at something with the naked eye and through the binos simultaneously and compare their size.

[Starkler]

Try pointing the binos toward the sky or something bright and then looking into the eyepieces a bit away from your eye you will see a disc of light. This is what we call the 'exit pupil'.

The aperture of the objective lens divided by the exit pupil size will give you the magnification. I hope that made sense.

[bytor666]

i know a great way to find out the magnification....just measure the exit pupil in the eyepieces and then divide that number into the objective lens.....or you could also put them on a tripod , and let the top star in orion's belt drift from edge to edge, (make sure that orion is at the closest point to exact south as possible). You then take this number, ( if it is minutes break it down into seconds), and then you divide it by 4 ,( i think im right about the 4)....cheers mate !!!!
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Mark
12" gso scope

[toetoe]

Thanks to all comments, there are some options there to try, so i will get into it and see how i go , thanks.

[toetoe]

My mothers words"we were told the binocs will magnify 5x, your father dosn`t now anything you should have asked me in the first place"
mothers always right that say. My reply "gee thanks mum"