Omid's Invention - Binoculars with Convergent or Divergent Field of View (1 Viewer)

[looksharp65]

Very nice report, Lars, and by someone qualified to do it too. :t:

Ed

Thank you Ed! Feeling a bit like a bad guy when Omid invested so much headwork.

Now for another tidbit from the goody bag of optics. The insight struck me that one a lot better way to achieve a laterally extended FOV would be to decenter the eyepiece's field stops laterally.

Just like the prism method, the total FOV would increase at the expense of the compound FOV. However without all the other disadvantages like eye strain/headache/diplopia and seemingly reduced magnification, not to mention the compromised image quality due to chromatic aberration and the need to fine-adjust the prism base direction for IPD.

Like previously mentioned, even a wide-angle binocular's FOV is about 40 degrees narrower than the human FOV, which means that an ordinary binocular's FOV represents a fraction of the human FOV. When moving the eyes within the view, the human FOV follows within the available FOV of the binocular.

This is why divergent FsOV or decentered fieldstops will consume parts of the compound FOV, and that is why wide-angle binoculars, roofs and porros alike, always will be a better way to expand the FOV.

//L

 

[Binastro]

I got better results with the faulty 6x18 yellow waterproof roofs, where it seems the tubes were not mechanically parallel and the operator just aligned the optics to compensate, giving a considerably wider FOV. I don't think I got much headaches, but didn't like them.
I'll see if I can find a faulty one to try again.

I presume that moving field stops laterally would need wide field eyepieces, so what is the point?

 

[looksharp65]

I got better results with the faulty 6x18 yellow waterproof roofs, where it seems the tubes were not mechanically parallel and the operator just aligned the optics to compensate, giving a considerably wider FOV. I don't think I got much headaches, but didn't like them.
I'll see if I can find a faulty one to try again.

I presume that moving field stops laterally would need wide field eyepieces, so what is the point?

Yup. No point, but then again a better way to expand the FOV than using prisms. Best way is still using wide field eyepieces.

//L

 

[Omid]

Hello Lars,

Thank you very much for taking time and testing various configurations according to my ideas. Your observations actually confirm my own observations and experiments. They show what this technique can achieve and what the challenges are. If I summarize your observations:

a) Diverging the axes of view: You confirmed that when viewing long-distance objects, the horizontal field of view of the binoculars is increased while the "overlap" between the left and right fields of view is no longer 100%. There will be overlap only at the medial portion of the fields of view so stereopsis (3D vision or depth Perception) only happens at this portion. Well, this is perfectly fine and exactly what happens in normal (un-aided) human vision. You focus your gaze at an object directly in front of you and the side of your fields of view don't overlap, they just give situational awareness and detecting motion.

This option is obviously not suited for viewing near objects. The opposite trick (converging the axes of view) is to be used here. Your observations confirm this.

B) Converging the axes of view: Here too you confirmed the validity of the concept: "At very close distance: A relaxed view with a perceived increase of magnification, similar to the view of a reverse-porro". That's exactly what I had claimed: Positioning the prisms in front of the objectives in the converging configuration will allow binocular viewing of very close objects.

Your other observations regarding color fringing, etc are all valid too. But as you noted they can be mitigated. Note also that we can put prisms both in front of the objectives and after the eyepieces. The second prisms can simply cancel out the color fringing and other undesirable effects of the frontal prisms (magnification of the binocular must be considered in choosing prism adopters).

Finally, I have achieved another great goal: I inspired you and a few others here to think outside the box and discover new possibilities in designing binocular instruments. As you discovered for yourself, a similar effect can be produced by laterally shifting the field stop of the binoculars. I had discovered this too and I have pending patents on this variation and several other variations (e.g. binoculars with tilted image planes).

The topic of optimal configuration for binocular vision is still open to exploration. All has not been discovered yet. You are now in the arena! Let's explore further together and if we discover some other interesting configurations, I'll be happy to file for a joint patent application on the the topic.

Thank you very much for your efforts again,
-Omid

 

[looksharp65]

Thank you Omid :t:

Again, I'd like to stress that the power of a prism placed outside of the objectives will be multiplied with the magnification. Hence, a 0,5 prism diopter lens will require 5 diopters of eyeball convergence when used at infinity.
At the same time, the image shift/increase of FOV will be a mere five meters per 1000 m FOV.

On the ocular side, prism powers must be significantly higher to even be detected - to regain eyeball parallelity they must match the magnified anterior prism power.

I disagree with you regarding the usefulness of a decreased medial compound FOV.
If we're dealing with a reasonably wide-angle 65 degree AFOV, every part of the FOV will consist of true binocular vision.
More than that, the "wide AFOV" will still cut away large parts of the human binocular field of view.
Diverging FsOV will further restrict the (already) restricted compound FOV.

And it does not stop there, unfortunately.
When using the naked eyes, the human binocular field of view will follow with the version movements (up, down, left and right and combined vectors allowing oblique gaze directions), albeit with some restrictions caused by the nose and the eyebrows.

At best, binoculars allow the eyes to roam the FOV, maintaining true binocular vision all the way to the field stops. There are undeniably lots of binoculars that will cause blackouts or kidney-beaning even with moderate version movements, but that's another problem.

With a further restricted compound FOV, it requires a more active physical directing of the binoculars since the available eye roaming area within the FOV will be clearly more restricted.

Regards,

Lars

 

[WJC]

Thank you Omid :t:

Again, I'd like to stress that the power of a prism placed outside of the objectives will be multiplied with the magnification. Hence, a 0,5 prism diopter lens will require 5 diopters of eyeball convergence when used at infinity.
At the same time, the image shift/increase of FOV will be a mere five meters per 1000 m FOV.

On the ocular side, prism powers must be significantly higher to even be detected - to regain eyeball parallelity they must match the magnified anterior prism power.

I disagree with you regarding the usefulness of a decreased medial compound FOV.
If we're dealing with a reasonably wide-angle 65 degree AFOV, every part of the FOV will consist of true binocular vision.
More than that, the "wide AFOV" will still cut away large parts of the human binocular field of view.
Diverging FsOV will further restrict the (already) restricted compound FOV.

And it does not stop there, unfortunately.
When using the naked eyes, the human binocular field of view will follow with the version movements (up, down, left and right and combined vectors allowing oblique gaze directions), albeit with some restrictions caused by the nose and the eyebrows.

At best, binoculars allow the eyes to roam the FOV, maintaining true binocular vision all the way to the field stops. There are undeniably lots of binoculars that will cause blackouts or kidney-beaning even with moderate version movements, but that's another problem.

With a further restricted compound FOV, it requires a more active physical directing of the binoculars since the available eye roaming area within the FOV will be clearly more restricted.

Regards,

Lars

Hi, Lars:

I’m just looking for your opinion. You may respond to: [email protected]

Is what Omid is trying to ascertain of any practical value, considering production costs in machining, testing, failure rates, collimation issues, and the seemingly limited market? Or, is he just rearranging deck chairs on Titanic? That great American sage, Jeff Goldblum—in Jurassic Park—said that just because you CAN do something, it doesn’t follow that you SHOULD.

He knows I wish him well. But, there needs to be a production “pay-off” that I have not been able to see—all realities considered.

I’m not poo-pooing—just fact finding. :cat:

Bill