full circle? (1 Viewer)

Regarding the IPD measurement, is it correct the a properly fitted binocular will
provide a full circular view of field? I think my eyes may be close set together
because on my Fujinon BFL 8x42, I was ONLY able to get the full circle when
the barrels were completely closed in. The fujinon's minimum IPD is 58mm, so
im assuming a binocular with any listed measurement of greater than 58mm
minimum will NOT work??
Are the manufacturer's measurements really accurate? If thats the case,
than im kind of limited in my choices for 10x42 good quality roofs.
Id really like to purchased the Vortex Viper 10x42, but the listed IPD minimum
is 59mm. I really dont want to have be buying on line than going through
a serires of exchanges and returns and refunds. Unfortunately, there are
no stores in my area that carry the Vipers, and the stores that are Vortex
dealers will NOT order the VIPER unless I commit to buy!

Thoughts?

Hi raptorbfl,

What you could do is to go to an optician to have your interpupillary distance measured. I'm assuming you don't wear spectacles as you're not sure what your IPD is. I'm a specs wearer so I know my IPD is 68 mm. Once you know what your IPD is, you can take further steps, but it really is important that you try the bins you want before you buy. You may want to find a shop who has them in store. Even good quality bins may be excellent for one person and not good for the next. Buying a pair of binoculars really is a very personal matter.
Hope my advice gives you a good start.

Greetings, Ronald

The 8x42 BFL actually measures 57-73 IPD.

The Nikon Monarch 10x42 Roof goes down to 55.

edz

raptorbfl said:

Regarding the IPD measurement, is it correct the a properly fitted binocular will provide a full circular view of field? I think my eyes may be close set together
because on my Fujinon BFL 8x42, I was ONLY able to get the full circle when the barrels were completely closed in.

Click to expand...

Yes, the view through a bino should appear as a circular field if your IPD is adjusted properly. HOWEVER, at close distances, it becomes more and more difficult for views from the two halves to overlap completely, and no binocular (except the Pentax Papilio models, which are designed to do so) can achieve perfect overlap at very close distances. The farther apart the oculars of the binos, the farther the distance at which this difficulty in achieving field overlap occurs. Since the Fuji BFL are a porro with very widely set objectives, you may have problems even at relatively far distances (20 feet) unless you can adjust the IPD downward from the setting that you use for looking at distant objects (It's a good idea to get a bino that adjusts to less than your IPD to allow for this compensation at close distances). If the circles don't overlap at distance, than the IPD is too wide for you (If you get double vision, then the binos are misaligned, which is a different problem altogether).

--AP