What is the 3D Effect? (1 Viewer)

[Oscar56]

This week I am, hoping to get a chance to test some alpha binos. My Nikon Monarch7 8x42 have severEd me well over the past 6 years, but it is time to test some higher end units.

So what is this 3D effect? it Sounds like field flatteners remove this effect. What should I be looking for?

 

[Gijs van Ginkel]

3D effect:: as if you are part of the space around you and there is the same feeling as observing with the naked eye: towers are rising up, deep beneath is a road with cars, or when walking in the mountains; you see deep below you a river with wild water running through it, birds circle in the sky and you feel the space in which they circle.
An attempt to make a poetric description of 3D. Do not expect that with a binocular certainly not with roof prism binoculars, but in that case imagination and phantasy are very helpful. The best description may be that you you see a certain depth in the image and that effect becames larger when the objecives are further separated from each other. A good example is the optical distance between eyepiece and objective as found in the periscopic binoculars as used in the trenches during WW-1, these deliver probably the strongest feeling of 3d.
I hope that is a bit clear, in Dutch I could say it more poetic..
Gijs van Ginkel

 

[Oscar56]

That is quite clear, thanks.

It almost sounds like some of the commentary when using 100 degree EPs for astronomical use. That feeling of falling into the view. But of course that is all your brain's perception because in most cases astronomical viewing is with a single EP.

 

[NDhunter]

As mentioned, 3-D is hard to explain and hard to evaluate. That means don't place much if any thought about the effect.

It is not measurable, but you do hear some users talk about it............

Jerry

 

[tenex]

It's a good question. Various properties have been described as "3D" in binoculars, principally (1) the stereoptic effect of wider separation of the objective lenses (which is rather minimal with most roof prism designs), or (2) the visual impression of classic binoculars, which some think have a more natural sense of depth than "flat-field" models.* But sometimes it's hard to tell exactly what someone means by 3D. Just try some different models, esp. flat-field (ELSV, NL, SF) vs not (SLC, UV, HT), and see what you think and how much it matters. None are awful.

(* - A sharp outer field means minimizing field curvature; such models also tend to have less pincushion distortion, though that's a different parameter, affecting behavior when panning. Read up on the difference between the two so you know what you're looking for/at. SLC models tend to be intermediate.)

 

[casscade]

Leica’s 7x42 is the one of the best examples for this imo, just an incredible natural view.

 

[jaymann]

Some people see 3D effect with shallow depth of field binocular, like bokeh effect.
Where as some see it with lowered power binoculars where everything is in focus, objects close to you and the far ones as well.
I see it when I focus my eyes on one object in the view and the move my hear to see objects in the background at different angles, like when riflescopes show parallax error.

 

[Troubador]

Where as some see it with lowered power binoculars where everything is in focus, objects close to you and the far ones as well.

The view through binos becomes compressed with increasing magnification so objects near to the observer appear to get closer and closer to objects further away. You could correctly call this a reduction in 3D. This effect is significantly reduced in 7x binoculars so that the image has more depth. Objects near the observer appear further apart from objects further away. I first noticed this when observing a coastal scene with which I was very familar (using 8x and 10x binos) and was shocked when using 7x to notice how far apart the small islands and headlands now appeared. This is in addition to the great depth of field (depth of sharpness one might call it) and it is this combination that makes 7x binos such a treat.

Lee