Intriging notion 3D?

[JOC]

I like to see what folks have an often check out the Buy and Sell threads just to have a nosey.  I saw this ad. and wondered about the notion that this instrument could provide an almost 3D view of planets.  I just wondered how that was achieved.  Is it due to the merging to two slightly differently focussed images please?

[Dave Smith]

You only get true 3D if the image perceived by each eye are different, ie from a different view point. You only see 3d with your own eyes for relatively close objects. e.g. if you look at some thing quite close and the look at it with one eye at a time the object will have a slightly different perspective and the background will have moved. The brain interprets these images as a 3D view. With binoculars looking at astro objects  the image in each eye will be identical so it is nor really 3D.

However, when viewed by both eyes you do get a simulated 3D view, at least the brain thinks so. I used to use binoviewers and in that case the light is split into the two eyepieces and so will be dimmer than normal but the brain seems to give a much superior image. My best ever view of Jupiter was with binoviewers in a C9.25.

Those binoculars will give wonderful views but not 3D.

Dave

[Davey-T]

There was somebody manufacturing 3D binoculars recently, not true 3D of the stars as I recall just randomly presented at different distances to appear 3D.

Dave

[BinocularSky]

In addition to Dave's comments, you also get false stereopsis in clusters, when they have different coloured stars. Knowing that it's not real does not detract from its pleasing aesthetic effect (and there's nothing wrong with enjoying a pleasing aesthetic effect, even if it is false )

[JOC]

How interesting.  If I ever get to a starparty maybe I'll be able to try a telescope fitted with a binocular viewing system just to see the effect.  Thinking about it I guess you could have a number of variations, two tubes producing a single image at the eye, one tube with a bino view-piece, true binocular type systems, single EP on a single tube - like most of us have,  Each must have their own merits.