Why two objective lenses? (1 Viewer)

Seeing Swarovski launch their latest BTX eyepiece module for their telescopes made me wonder why binoculars are made with two objective lenses? A single objective lens could be larger, yet combined with two eyepieces or ease of viewing. Might this be a way of addressing some of the weaknesses in optical performance, which as has been pointed out before, mostly fail to match the optical performance of some of the best low power telescopes?

Just curious...

Interesting idea but it introduces its own challenges. You need a beam splitter to send the image to two eyeypieces (no doubt with its own array of optical problems) and then there is the issue of providing a sufficiently wide (I mean a wide span from min to max) IPD adjustment. And all while keeping the weight down. Handling would be a bit marmite depending on where the focus was positioned. Close focus would be good though since there would be no cross-eyed effect.

Lee

The two binocular objectives are looking through two slightly different and rapidly-changing columns of air. This allows the brain to use an averaging factor to improve visual acuities.

One might say the problem is alleviated by using only one objective. But, as Lee points out, having only one objective introduces other avenues for problems to arise, not the least of which is alignment for the two lines of sight—especially as the IPD is changed. If one will visit sites dedicated to those beam-splitting arrangements, it will soon become clear that collimation issues is more pronounced than with binoculars in general. Most people see problems in observing as being related to an instrument. In reality, they relate as much to, usually not considered, physiological conditions.

Just a thought.

Bill

Binomania has a recent comparison of the new Swaro. binoviewer with the Kowa Highlander
and the Docter Aspectem.

Read the review. The Swaro. is very good, but not in some ways to the big twin binoculars.

The advantage would be to scope users who pack and carry things to a site. I suppose more
tests are upcoming on how the viewer compares to the single eyepieces.

In my experience 2 eyes are better than one, in many ways.

Recently, I find I like 15-16 X binoculars better than a spotter, in many ways.

Jerry