Interesting Optics Trade discussion on where Leica binoculars are made. (1 Viewer)

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I'm perplexed by this video. How can making a video through one lens of a binocular - roof or porro - demonstrate a 3D image or lack of one? It's missing the bi in binocular...

R-L

You're correct. The video couldn't really demonstrate a 3D image or lack of one. The fellow was well meaning and at first I thought I could see a difference in the porro and roof videos, but really there isn't because the video itself is not in 3D. I deleted the video. Here are some true 3D videos created using software, but you have to use 3D glasses to get the 3D effect. Of course there are many 3D movies you can also watch in 3D. This is what a porro looks like! Cool huh!

"I created a 3D ANAGLYPH video based on the game "Crytek Back to Dinosaur Island" by using the latest 3D software technology. You need to use 3D ANAGLYPH GLASSES to get a 3D effect."

Plastic 3D Glasses - The Original Pro-X Anaglyph 3D Glasses. Includes a Bonus Virtual Tours National Park 3D Booklet : Electronics

Plastic 3D Glasses - The Original Pro-X Anaglyph 3D Glasses. Includes a Bonus Virtual Tours National Park 3D Booklet : Electronics

www.amazon.com

Amazon.com : 3d movies

 

[CharleyBird]

So Denco, do I need the 3D glasses to see the effect you see through your porros?

 

[wdc]

No. Not needed! You need them for the 3D clips and movies, though. The 3D effect with the Anaglyph glasses in these clips and movies will be more exaggerated than you will get through a porro prism binocular, but the effect is similar. The 3D effect of the porro is from the wider spacing of the objective lenses allowed because of the offset prisms used in a porro.

I would expect that if the glasses are spaced wider than the normal spacing of the eyes, the primary effect will be that the world will look 'smaller' not that a 3d sensation is 'exxaggerated'.

 

[henry link]

Experimenting recently with periscopes to increase the stereo baseline of my unaided eyes to various widths I found, not surprisingly, that the world has exaggerated "3D" at the baseline width used in Porro binoculars compared to "normal" human stereopsis. Objects also appear smaller than normal. Both effects increase as distance decreases. Another anomaly is that the smaller appearing objects also appear sharper than normal, but without any corresponding increase in true resolution. This might explain the reports of superior sharpness in Porros, which appears to me to be an illusion that goes hand in hand with the smallness illusion. I believe details appear to be finer simply because they appear to be smaller.

 

[tenex]

This video shows the difference through a roof prism and a porro. Big difference!

The video shows the difference in depth of field between 10x and 25x. It's curious how people hear there's a big difference here, and find one...

Objects also appear smaller than normal.

Is the geometry telling you that (nearby) objects are even closer than they are, so the brain concludes they must be smaller?

 

[henry link]

Is the geometry telling you that (nearby) objects are even closer than they are, so the brain concludes they must be smaller?

That's been my assumption since I first noticed this effect when I bought my first roof prism binocular. The phenomenon has come up repeatedly in discussions of roof vs Porro since the early days of Birdforum, usually when somebody mistakes it for a genuine difference in magnification.

For a while I couldn't decide whether the roof or Porro presentation of the apparent size of objects was more "correct", given the already unnatural addition of magnification to the image in binoculars. My recent experiences, using periscopes without magnification rather than binoculars, has finally convinced me that a binocular objective baseline that conforms to the eyes' baseline comes closer to duplicating the natural eye/brain impression of "3D" and apparent object sizes than the extended Porro baseline. An extended baseline (with or without magnification) creates a kind of hyper-stereopsis: impressive and fun to look at, but not natural.

 

[wdc]

I don't think there's anything inherently natural about optical devices. They introduce all sorts of differences into one's perceived field of view. What Henry is pointing out is that the normal eye displacement that Roofs can provide, make for a less distorted perception of the view, in his opinion, than Porros, with an extended baseline.

Dennis, what you're saying is that you prefer the distorted view, which is fine, but it certainly isn't natural. Perhaps you'll be selling some porros soon, so it is important for you to broadcast their virtues, as you see them, to the forum...

-Bill

 

[SUPPRESSOR]

I don't think there's anything inherently natural about optical devices. They introduce all sorts of differences into one's perceived field of view. What Henry is pointing out is that the normal eye displacement that Roofs can provide, make for a less distorted perception of the view, in his opinion, than Porros, with an extended baseline.

Dennis, what you're saying is that you prefer the distorted view, which is fine, but it certainly isn't natural. Perhaps you'll be selling some porros soon, so it is important for you to broadcast their virtues, as you see them, to the forum...

-Bill

Having used Roof prism bins for birding since 1971 and occasionally going back and trying porro's, regardless of image quality, with porro's slung around your neck one feels a proper joskin🤓

 

[Paultricounty]

Having used Roof prism bins for birding since 1971 and occasionally going back and trying porro's, regardless of image quality, with porro's slung around your neck one feels a proper joskin🤓

Really, now I’m feeling like a geek with those SEs and Habicht’s around my neck 🙃👨🏻‍🔬.
And I always thought the guy with the Tascos was the bumpkin.

 

[SUPPRESSOR]

Really, now I’m feeling like a geek with those SEs and Habicht’s around my neck 🙃👨🏻‍🔬.
And I always thought the guy with the Tascos was the bumpkin.

Well, I have owned both of those models in the past and as fine as they both are....it comes down to that joskin thing!!!

Or to put it another way.......What's the difference between a Skoda and a sheep? You feel less embarrassed getting out of a sheep!

 

[William Lewis]

That's been my assumption since I first noticed this effect when I bought my first roof prism binocular. The phenomenon has come up repeatedly in discussions of roof vs Porro since the early days of Birdforum, usually when somebody mistakes it for a genuine difference in magnification.

For a while I couldn't decide whether the roof or Porro presentation of the apparent size of objects was more "correct", given the already unnatural addition of magnification to the image in binoculars. My recent experiences, using periscopes without magnification rather than binoculars, has finally convinced me that a binocular objective baseline that conforms to the eyes' baseline comes closer to duplicating the natural eye/brain impression of "3D" and apparent object sizes than the extended Porro baseline. An extended baseline (with or without magnification) creates a kind of hyper-stereopsis: impressive and fun to look at, but not natural.

Skipped through to page 9 (I think?). I can't say I missed the 3d effect when I used exclusively roofs so it probably is a greatly over stated benefit. I use porro's mainly as they seem to be the most cost effective way of getting an otherwise expensive view. As its a hobby for me I like that. Yellow wagtails today in Cambridgeshire were a new view for me today through the trusty habichts-maybe I saw more detail as I could see round the sides a little more but I doubt it at 75 yards!

 

[wdc]

I'd use porros more often if they had the eye relief I need. I do have a few pair, one 6x30, and one 15x50, but they don't get that much use these days.

 

[Paultricounty]

I'd use porros more often if they had the eye relief I need. I do have a few pair, one 6x30, and one 15x50, but they don't get that much use these days.

Hmmm, maybe we need to start a conversation about what people are depending on what binoculars they carry around there neck. You know like porros carriers are geeks and swarovski roof carriers are cool and Leica roof carriers are chick. What about those guys that carry the binos in there hands all the time or in a holster at there sides like gun slingers. Are they like alphas?

I’m sure that won’t be subjection at all, and we should be able to clearly categorize them definitively.😝

 

[Renze de Vries]

Experimenting recently with periscopes to increase the stereo baseline of my unaided eyes to various widths I found, not surprisingly, that the world has exaggerated "3D" at the baseline width used in Porro binoculars compared to "normal" human stereopsis. Objects also appear smaller than normal. Both effects increase as distance decreases. Another anomaly is that the smaller appearing objects also appear sharper than normal, but without any corresponding increase in true resolution. This might explain the reports of superior sharpness in Porros, which appears to me to be an illusion that goes hand in hand with the smallness illusion. I believe details appear to be finer simply because they appear to be smaller.

Hi Henry,
Good stuff, thank you. I tend to agree with your findings, certainly when it comes to the aspect of sharpness. However, as I've always understood, sharpness is only one aspect of resolution. And to me, resolution is what really counts. If we're comparing porro's and roof binoculars on resolution we have tot take other factors of the design into account as well. Notably the complexity vs simplicity of the light path. As the optical construction of the porro binocular is (usually?) more simple, it should result in a more uncluttered, cleaner view. I think porro binoculars in general are capable of better resolution. And this is what I see, time and time again, when it comes to resolution my Schmidt Pechan roof binoculars are bested by my Abbe Koenig roofs which are bested by my porro binoculars.
Renze

 

[Paultricounty]

Hi Henry,
Good stuff, thank you. I tend to agree with your findings, certainly when it comes to the aspect of sharpness. However, as I've always understood, sharpness is only one aspect of resolution. And to me, resolution is what really counts. If we're comparing porro's and roof binoculars on resolution we have tot take other factors of the design into account as well. Notably the complexity vs simplicity of the light path. As the optical construction of the porro binocular is (usually?) more simple, it should result in a more uncluttered, cleaner view. I think porro binoculars in general are capable of better resolution. And this is what I see, time and time again, when it comes to resolution my Schmidt Pechan roof binoculars are bested by my Abbe Koenig roofs which are bested by my porro binoculars.
Renze

I go along with that with one caveat , other than swarovski Habicht’s there are no porros that have kept pace optically Technologically with the highend, (high grade, alpha) roof choices we have. There are no (imo) porros that have the resolution of the EL’s, SF’s, Noctivids and others in that group. Also depends on which AK your comparing to which SP.

Paul

 

[henry link]

Hi Renze,
In my experience the resolution of binoculars is not related to the prism type at all (except for non-phase corrected roof prisms). I've only measured a few binoculars that came close to diffraction limited at their full apertures and those used all three of the prism types you mentioned. Objective lens designs with well corrected axial aberrations (and no major assembly defects) are what I've found is required for high resolution and that's where most binoculars are not good enough.

Hi Paul,
I don't think you're talking about true resolution, which is usually not that impressive in binoculars, new or old, even in the vaunted "alpha" brands. To measure a binocular's true resolving power on a resolution chart like the USAF 1951 requires boosting the magnification to a value equal to or a bit above the aperture in mm. If you do that be prepared for some surprises and disappointments.

Henry

 

[Paultricounty]

Hi Renze,
In my experience the resolution of binoculars is not related to the prism type at all (except for non-phase corrected roof prisms). I've only measured a few binoculars that came close to diffraction limited at their full apertures and those used all three of the prism types you mentioned. Objective lens designs with well corrected axial aberrations (and no major assembly defects) are what I've found is required for high resolution and that's where most binoculars are not good enough.

Hi Paul,
I don't think you're talking about true resolution, which is usually not that impressive in binoculars, new or old, even in the vaunted "alpha" brands. To measure a binocular's true resolving power on a resolution chart like the USAF 1951 requires boosting the magnification to a value equal to or a bit above the aperture in mm. If you do that be prepared for some surprises and disappointments.

Henry

I stand corrected. I was using the term or my understanding incorrectly. I was pertaining to an objects detail and how much can be resolved from binocular to binocular. Thx Henry.

Paul

 

[Mac308]

To measure a binocular's true resolving power on a resolution chart like the USAF 1951 requires boosting the magnification to a value equal to or a bit above the aperture in mm. If you do that be prepared for some surprises and disappointments.

Henry

This is true, and I've found the 1951 chart to be the best.

A good explanation with other helpful links can be found here: 1951 USAF resolution test chart - Wikipedia

A downloadable and printable pdf of the chart here: http://www.takinami.com/yoshihiko/photo/lens_test/USAF.pdf

My advice is to send the pdf to a good printer and have it printed at the highest resolution on waterproof paper.

Resolution is paramount to me, and the chart takes away confirmation biases and all manner of other subconscious (or not so subconscious) prejudices.

I had an early model Leica 8x32 BR. Some years after, I aquired a NIB Zeiss 8x32 FL. There was a lot to like about the FL, and I had read so many positive reviews I had to have one for myself, fully intending to sell my Leica's if I found the Zeiss to my satisfaction. The Zeiss arrived, and I lived with them for a week, comparing the two under varying light conditions. They "seemed" close, but the real eye opener, and deciding factor, was the USAF 1951 Resolution chart. In any light condition at any time of day, the Leica was the surprising winner. No contest. It had obviously finer resolution. I sent the Zeiss back, and continued on with the 8x32 BR's (which in 2014 I replaced with the HD model).

 

[Canip]

Two personal caveats, if I may:

• checking the resolution using a USAF 1951 means you are using YOUR eyes, and the result remains therefore somewhat subjective (even more so as the condition of people‘s eyes tends to vary from day to day or even more frequently)
• the USAF provides only info as to resolution for items printed black on white background. Nature, however, is rarely just black and white, and individual color perception is a highly subjective matter which has a huge influence on perceived optical performance of a bino.

I am frequently using the USAF myself (with boosters, as suggested by Henry), but I am aware that the results are not the ultimate criterion to judge binocular performance.

Canip