Method for setting IPD (1 Viewer)

I've read many posts where folks actually measure their IPD and set their bins and forget it. I believe the IPD changes a few mm based on distance.

I've been doing this method for a while without thinking about it. Seems to work for me and requires no measurements. And can be adjusted for every distance.

Find a target at the distance you'll be viewing. Defocus your binoculars so everything is blurry. Notice you can now see the FOV (circle of view) edges clearly. Open bins wider and close down until the circles overlap. But, don't try to watch the edge of the FOV while doing this. Just look in the center of the defocused FOV.

You'll actually "feel" when the circles overlap perfectly.

Seems like a fast way to nail the IPD at any distance... try it and see if it works for you.

I think if you do this with everything in focus you can't see the FOV circles overlap the way they should.

Cheers

oleaf said:

I've read many posts where folks actually measure their IPD and set their bins and forget it. I believe the IPD changes a few mm based on distance.

I've been doing this method for a while without thinking about it. Seems to work for me and requires no measurements. And can be adjusted for every distance.

Find a target at the distance you'll be viewing. Defocus your binoculars so everything is blurry. Notice you can now see the FOV (circle of view) edges clearly. Open bins wider and close down until the circles overlap. But, don't try to watch the edge of the FOV while doing this. Just look in the center of the defocused FOV.

You'll actually "feel" when the circles overlap perfectly.

Seems like a fast way to nail the IPD at any distance... try it and see if it works for you.

I think if you do this with everything in focus you can't see the FOV circles overlap the way they should.

Cheers

Click to expand...

I tried your method for setting IPD and it didn't really work for me! I guess I don't get it.

Oleaf,
Don't miss the IPD discussion raging under the 8x32 FL sweetness thread. That has undoubtedly contributed to the wholesale ignorance of your idea!

I tried your method and think it's useful. The point is, I believe, that defocusing relaxes one's attention from anything interesting in the view to be looked at, and makes the sharp field stops stand out better, and thus easier to bring into alignment. A pitfall exists however--defocusing brings the image to some apparent point other than infinity, and thus the eyes potentially slightly crossed rather than parallel, so one must be sure to keep the eyes relaxed and gaze at infinity, and not "try" to examine the out of focus image.
Ron

Ronh,

You described the process much more cleanly than I had originally done.

It was just something I noticed I did from time to time and wanted to understand why I did it this way. I'm not anal about IPD but believe many go way overboard and try to find a hard number. I just did what seemed comfortable. I've never measured my IPD and possibly never will.

Just seemed easier for a given distance to find the right and left field overlap.

But... you should focus your eyes on the out of focus subject. You don't want your eyes focused at infinity if you're going to look a an object at close range. You're eyes must converge at close range... just like they need to be more parallel at infinity.

Find a target... defocus... adjust IPD... refocus. Maybe only do it when the view doesn't "feel" right. Like going from 10 yards to 300 yards.


Dennis,

Maybe so. It was just an idea that worked for me.

Cheers