Focus Binoculars Beginnes question

[Run45]

Hi.. This ist my first post.

Just got myself 7x50 binoculars an am quit happy with them.

One thing puzzles me a bit. I assumed that the stars are from the earths point of view(and from the binoculars point of view) at infinity and assumed therefore that the focus dial would need to be set to the maximum position (in one direction). But it turns out that I have to dial the focus dial just a little but noticeable bit back to get the best image.

Is this common? Why is it like this? Is this a mechanical issue of the binoculars?

Do people refocus a lot/bit when looking at the stars?

Thanx for any reply

[ronin]

That is normal, they engineer in a bit more adjustment then you actually need so they in effect "go past infinity".

If they were done such that the end of movement was infinity then any error could mean they would never focus.

The other reason is that your eyes can be 20/20, short or long sighted.

I am short sighted and a bit more movement past infinity would be useful as then they would just be usable without the glasses being on.

One set of binoculars I will give away as they do not have the travel past infinity and do not have the eye relief for wearing glasses. So no use to me now, shame as they are nice lightweight one with decent optics.

[Run45]

thanx ronin for the info. i can understand that its actually an advantage to have a little wiggle room on the binoculars.