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Review (1 Viewer)

wdc

Well-known member
Here is the latest review of the EDG 8X42 updated by Tobias, for those interested.

Andy W.

http://www.greatestbinoculars.com/allpages/reviews/nikon/nikonedg8x42/nikonedg8x42review.html

An enjoyable read, but, to me, full of self-contradictions, and generates a confusion of terms for me.

For example, I always thought the term flat field meant the focal plane across the visual field was in focus from edge to edge, whereas a curved field meant that some % of the periphery of the focal plane was not in focus when the center was, but could be brought to focus, by re-adjusting the focus wheel, so the plane of focus was curved, by design.

Tobias references some reviews of lenses for cameras, and points out a photo of his own of a grid of lights, out of focus, that illustrate pincushion distortion, proclaiming that 2 dimensional '3d pop' is best exemplified by some degree of this type of distortion. The apparent illusion is that the center of the image is pushed 'forward' towards the viewer, and the rest curves away, the inverse effect of the illusion of 'rolling ball'... so does 3d pop still manifest when shot composition is not dead center, like when there's 2 people in a shot? ...and is it equally effective in static and moving imagery?

It is not yet clear to me whether curvature of the focal plane and barrel or pincushion distortion of a grid are inextricably linked when it comes to binoculars. In other words, can one have a relatively flat focal plane in a visual field, combined with barrel or pincushion, especially with multiple glass elements?

To me the impression of 'flatness' in an image has more to do with depth of field, and value structure, rather than relying on an engineered spatial distortion across the entire field, introduced by optics. Some of Ansel Adams work has a strange quality to me because he created exaggerated depth of field through the use of a small f stop, and a correspondingly longer exposure. I suspect he may have been thinking of the epic constructions of Bierstadt and Church, landscape painters from the previous century, where one could stand in front of a massive canvas and wander the eye all over it marveling at the details in every nook and cranny.

At any rate, I digress, and we're talking about the view through binoculars, not 2d static imagery on a wall, or a computer monitor. So, what does flat field refer to then when it comes to binoculars? A curved or flat focal plane, or a visual distortion that is seen when looking at a grid? (or both)

I'll briefly mention some of the language Tobias uses when referencing color:

"Colour reproduction
is very neutral with extreme colour saturation. Very lifelike colours. Other glasses who are a bit on the cold side as the Swarovision, brighter as the HT, or even on the green side as the SF just don´t deliver this quality. The famous Nikon ED glass works well here."

"Extreme" colour saturation, in my mind, is neither lifelike, nor is it neutral.
I agree with his perception of the Swaro as 'cool', and the SF as 'green', though I don't even think about at all if I'm using either one. To me, not a problem.

Other terms like 'brutal contrast' come to mind as well. I'll put that down to Tobias' propensity to magnify subtle perceptual distinctions into large scale phenomena, as well as perhaps the shortcomings of his thesaurus.

All said and done, I do appreciate the effort and the passion, and the photos are always good. Any reader is advised to study numerous reviews, and then, most importantly, try binoculars out for yourself, and trust your own experiences and perceptions above others. Thats what counts.

-Bill
 
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Binastro

Well-known member
Hi Bill,

Some of the Canon IS binoculars have flat fields and pincushion distortion as do some Nagler astro eyepieces.

Regards,
B.
 

eitanaltman

Well-known member
I always thought the term flat field meant the focal plane across the visual field was in focus from edge to edge, whereas a curved field meant that some % of the periphery of the focal plane was not in focus when the center was, but could be brought to focus, by re-adjusting the focus wheel, so the plane of focus was curved, by design.

.... It is not yet clear to me whether curvature of the focal plane and barrel or pincushion distortion of a grid are inextricably linked when it comes to binoculars. In other words, can one have a relatively flat focal plane in a visual field, combined with barrel or pincushion, especially with multiple glass elements?

.... So, what does flat field refer to then when it comes to binoculars? A curved or flat focal plane, or a visual distortion that is seen when looking at a grid? (or both)

The term "flat field" is thrown around a lot; some use it to mean "sharp to the edge", other times people use it to mean "straight lines (no pincushion)." But my understanding is that a "flat field" most accurately refers to field curvature, as you noted.

I've read enough of Henry's posts to know that correction of field curvature / astigmatism (which impact sharpness as you move to the edge) is NOT related to rectilinear distortion (barrel vs pincushion).

I have a feeling these concepts have become linked on binocular forums in no small part because of the "Swarovision" prominence and dominance. When Swaro introduced the EL SV series, all the talk was "flat field! flat field!" and these binoculars happen to have excellent correction of astigmatism + field curvature (ergo very sharp to the edge) and ALSO they chose to aggressively correct pincushion distortion so they have high AMD (rolling ball effect).

So I don't think it's "inextricably linked", other than the colloquial linkage that has arisen as a consequence of the Swarovision defining the "flat field" paradigm for the modern roof. So in many people's minds, thanks to the EL SV, the term "flat field" makes them think "sharp edge to edge, straight lines, but also rolling ball".


To me the impression of 'flatness' in an image has more to do with depth of field, and value structure, rather than relying on an engineered spatial distortion across the entire field, introduced by optics.

As above, I think it's important to distinguish between "technical" terms (low field curvature / pincushion vs barrel distortion / etc) that are precisely defined, vs. colloquial subjective descriptors. If someone compares two binoculars and comments "wow the image on Binocular X feels so much deeper, whereas Y just feels flat in comparison" ... well, there's a lot of things they could mean by that!

I currently have in my possession a 10x32 EDG, an 8x42 Monarch HG, a 10x42 Trinovid BR, and an 8x32 Ultravid HD, listed in order from "flattest" to "most curvalicious". I absolutely notice what Tobias described as "images render space in a flat, compressed way" with both Nikons comparing to the two Leicas. Something about the view in the Nikons (which both have "field flatteners") makes the depth of the view feel a bit "compressed"; I am very confident it's not my imagination... as you noted, with photography you can create a sense of artificial deepening or compression by manipulating the visual plane / focus depth, so it's a real phenomenon in theory.

If I had to describe it, my best analogy is a "diorama effect", where layers of depth feel flattened as though real objects appear to almost be flat cut-outs vs 3D. For example, looking over the tops of trees, where there's a lot of depth from the closest to the farthest tree, the full depth of the trees feels compressed/flattened towards the viewer, and the trees themselves don't present as "deep". The EDG (which most aggressively corrects pincushion + field curvature, although neither as much as a Swaro SV) shows it the most, the MHG to a lesser extent. The UVHD 32, which has plenty of pincushion AND field curvature with zero AMD, feels incredibly "deep" and "3D" in comparison when I swap. Now, I realize the 8x mag of the UV gives it a "depth" advantage vs the 10x of the EDG, but since I have two other models (one 8x and one 10x) with which to compare, I do think there's something to it.

As an interesting side anecdote here -- the 8x32 UVHD are my wife's binoculars. She's a one binocular gal, and she LOVES those Leicas, and only uses them. When I get a new binocular in house to play with, I like to hand it to her to try out just to get her off-the-cuff impressions (she doesn't know anything about technical optical stuff, just raw subjective reaction).

I was really hoping she would like the EDG, since she had used Nikons for decades prior to getting the Leica this year, and more importantly the EDG have a very narrow minimum IPD, and my wife is on the extreme narrow end (52-53mm range). When she tried the EDG, however, she immediately said, "oh, these seem weird! they are very clear but it feels like I'm looking at a microscope slide!" (she is a lab scientist so this wasn't a random analogy). She switched back to her Leicas and said "yes, this feels so much more natural!" When I pointed out the 10x vs 8x focal plane difference, she grabbed the 10x42 Trinovids and compared and she definitely felt it was something unique to the EDG, not 10x magnification (and the Trinovid has a smaller FOV than the EDG, so it's also not the 8x UV's advantage in FOV).

After probing a bit to understand what she meant (I tried my best not to "lead" her by revealing anything about flat fields vs curvature etc) it was clear she was experiencing the phenomenon noted above, and her reaction of "like looking at a microscope slide" was her trying to convey that it felt like the image was "compressed" and felt "too close" to her, like a picture being shoved in front of her face, whereas with the Leica it felt more "natural" as though she saw the extra detail, but the subject still felt "properly placed" in space.

So while she could recognize the quality of the EDG optics, she just found them subjectively distasteful and they were her least favorite of the 4 options noted above.

EDIT: I also wanted to note that, while I do NOTICE the effect, it doesn't really bother me too much. The EDG view is otherwise just phenomenal, and thankfully they implemented a very "tasteful" approach to flattening, retaining just enough pincushion and field curvature to not make it feel excessively flat in real world use (e.g. panning doesn't feel unnatural, in fact the 8x42 MHG to my eyes exhibits more "rolling ball" than the 10x32 EDG).
 
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mfunnell

Registered Confuser
Thanks Eitan - a most excellent post. You said some of the things I had rolling (!) around in my head far better than I would have.

...Mike
 

tenex

reality-based
Antarctica
Yes Eitan, this is exactly my impression of "flat field" and how (largely thanks to Swarovision) it got confused with "less rectilinear distortion". The only thing I would add regarding field curvature itself is that adding field flatteners also introduces complex distortion transitions near the field edge which some can find distracting ("mustache distortion", "Absam ring"). I don't find it as disturbing as the obvious astigmatism of the pre-SF Zeisses for example, but I dislike it and will gladly accept a modest loss of sharpness at the edge instead.
 

SeldomPerched

Well-known member
The term "flat field" is thrown around a lot; some use it to mean "sharp to the edge", other times people use it to mean "straight lines (no pincushion)." But my understanding is that a "flat field" most accurately refers to field curvature, as you noted.

I've read enough of Henry's posts to know that correction of field curvature / astigmatism (which impact sharpness as you move to the edge) is NOT related to rectilinear distortion (barrel vs pincushion).

I have a feeling these concepts have become linked on binocular forums in no small part because of the "Swarovision" prominence and dominance. When Swaro introduced the EL SV series, all the talk was "flat field! flat field!" and these binoculars happen to have excellent correction of astigmatism + field curvature (ergo very sharp to the edge) and ALSO they chose to aggressively correct pincushion distortion so they have high AMD (rolling ball effect).

So I don't think it's "inextricably linked", other than the colloquial linkage that has arisen as a consequence of the Swarovision defining the "flat field" paradigm for the modern roof. So in many people's minds, thanks to the EL SV, the term "flat field" makes them think "sharp edge to edge, straight lines, but also rolling ball".




As above, I think it's important to distinguish between "technical" terms (low field curvature / pincushion vs barrel distortion / etc) that are precisely defined, vs. colloquial subjective descriptors. If someone compares two binoculars and comments "wow the image on Binocular X feels so much deeper, whereas Y just feels flat in comparison" ... well, there's a lot of things they could mean by that!

I currently have in my possession a 10x32 EDG, an 8x42 Monarch HG, a 10x42 Trinovid BR, and an 8x32 Ultravid HD, listed in order from "flattest" to "most curvalicious". I absolutely notice what Tobias described as "images render space in a flat, compressed way" with both Nikons comparing to the two Leicas. Something about the view in the Nikons (which both have "field flatteners") makes the depth of the view feel a bit "compressed"; I am very confident it's not my imagination... as you noted, with photography you can create a sense of artificial deepening or compression by manipulating the visual plane / focus depth, so it's a real phenomenon in theory.

If I had to describe it, my best analogy is a "diorama effect", where layers of depth feel flattened as though real objects appear to almost be flat cut-outs vs 3D. For example, looking over the tops of trees, where there's a lot of depth from the closest to the farthest tree, the full depth of the trees feels compressed/flattened towards the viewer, and the trees themselves don't present as "deep". The EDG (which most aggressively corrects pincushion + field curvature, although neither as much as a Swaro SV) shows it the most, the MHG to a lesser extent. The UVHD 32, which has plenty of pincushion AND field curvature with zero AMD, feels incredibly "deep" and "3D" in comparison when I swap. Now, I realize the 8x mag of the UV gives it a "depth" advantage vs the 10x of the EDG, but since I have two other models (one 8x and one 10x) with which to compare, I do think there's something to it.

As an interesting side anecdote here -- the 8x32 UVHD are my wife's binoculars. She's a one binocular gal, and she LOVES those Leicas, and only uses them. When I get a new binocular in house to play with, I like to hand it to her to try out just to get her off-the-cuff impressions (she doesn't know anything about technical optical stuff, just raw subjective reaction).

I was really hoping she would like the EDG, since she had used Nikons for decades prior to getting the Leica this year, and more importantly the EDG have a very narrow minimum IPD, and my wife is on the extreme narrow end (52-53mm range). When she tried the EDG, however, she immediately said, "oh, these seem weird! they are very clear but it feels like I'm looking at a microscope slide!" (she is a lab scientist so this wasn't a random analogy). She switched back to her Leicas and said "yes, this feels so much more natural!" When I pointed out the 10x vs 8x focal plane difference, she grabbed the 10x42 Trinovids and compared and she definitely felt it was something unique to the EDG, not 10x magnification (and the Trinovid has a smaller FOV than the EDG, so it's also not the 8x UV's advantage in FOV).

After probing a bit to understand what she meant (I tried my best not to "lead" her by revealing anything about flat fields vs curvature etc) it was clear she was experiencing the phenomenon noted above, and her reaction of "like looking at a microscope slide" was her trying to convey that it felt like the image was "compressed" and felt "too close" to her, like a picture being shoved in front of her face, whereas with the Leica it felt more "natural" as though she saw the extra detail, but the subject still felt "properly placed" in space.

So while she could recognize the quality of the EDG optics, she just found them subjectively distasteful and they were her least favorite of the 4 options noted above.

EDIT: I also wanted to note that, while I do NOTICE the effect, it doesn't really bother me too much. The EDG view is otherwise just phenomenal, and thankfully they implemented a very "tasteful" approach to flattening, retaining just enough pincushion and field curvature to not make it feel excessively flat in real world use (e.g. panning doesn't feel unnatural, in fact the 8x42 MHG to my eyes exhibits more "rolling ball" than the 10x32 EDG).

Eitan, thank you for this as it helps clear up things that I know I have sometimes carelessly and, to be honest, without realizing, lumped together in my mind.

I was very interested in your wife's reactions to the Nikon EDG vs. the Leica. I have a 7x42 EDG as well as a Leica UVHD Plus 8x32 and UVHD Plus 7x42. So I am familiar with the 32 your wife likes to use, and have also been able to compare a like mag. x objective size (7x42) EDG with UVHD plus.

I'd be interested if you and/or your wife feel the same as me, which is not just to do with the microscope slide feeling (I get that too) but with the two dimensionality and lack of depth making me feel a bit uncomfortable, a bit queasy as I focus in on the subject. It's not rolling ball as I am not panning in these circumstances. It's is as though the 'unreality' of the view affects me physically. That's not to say I dislike it once I get there; in fact I like the EDG very much indeed for its colour and other qualities but it is as said a bit uncomfortable to start with when altering the view and adjusting the binoculars to it.

I do share Tobias's views on camera lenses as well; that for instance the older Leitz/Leica lenses (Dr Mandler era - Midland plant designs) appeal to me more than the Blankpresse ASPH lenses more recently out of Solms and Wetzlar, for the same reasons he cites. Some of those older lenses are enjoying a resurgence as other users appreciate their 'Gestalt'.

Tom
 
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eitanaltman

Well-known member
Eitan, thank you for this as it helps clear up things that I know I have sometimes carelessly and, to be honest, without realizing, lumped together in my mind.

I confess to having done the same many times, but during these slow pandemic times as I'm spending my vacation money on binoculars instead of vacations, I've been spending a lot of time reading old forum posts from the technical types trying to understand what I'm seeing. In researching the EDG and MHG, it's hard to not stumble across old threads where Henry is explaining the difference between (rectilinear) distortion correction vs edge sharpness and how they are unrelated... so it's all fresh in my mind o:D


I was very interested in your wife's reactions to the Nikon EDG vs. the Leica. I have a 7x42 EDG as well as a Leica UVHD Plus 8x32 and UVHD Plus 7x42. So I am familiar with the 32 your wife likes to use, and have also been able to compare a like mag. x objective size (7x42) EDG with UVHD plus.

I'd be interested if you and/or your wife feel the same as me, which is not just to do with the microscope slide feeling (I get that too) but with the two dimensionality and lack of depth making me feel a bit uncomfortable, a bit queasy as I focus in on the subject. It's not rolling ball as I am not panning in these circumstances. It's is as though the 'unreality' of the view affects me physically. That's not to say I dislike it once I get there; in fact I like the EDG very much indeed for its colour and other qualities but it is as said a bit uncomfortable to start with when altering the view and adjusting the binoculars to it.

I don't get any physical discomfort or queasiness, but my wife clearly found the EDG view to be uncomfortable. I don't know if this is related, but my wife is VERY prone to motion sickness / seasickness (whereas I am mostly immune) and she also has poor vision and wears glasses (I do not). I think tenex's point above about the complex distortion patterns potentially feeling more unnatural has some merit, that is what turned me off the most about the Kowa Genesis 10x33 (which I otherwise loved), that binocular had some wacky stuff happening once you get past 50-60% of the way off axis, gave a real "funhouse mirror" effect when panning back and forth.

Since you have both the EDG and UVHD in 7x42, do you agree with Tobias' assessment of how the Leica feels "wider" and "deeper" even though they have the same FOV? I have been musing over a high end 7x42 for a long time, but after reading Tobias' assessment and also experiencing the EDG view for myself, it made me decide to avoid the EDG version (there was one on eBay recently for around $1100 which I would likely have bought otherwise to try).

And, speaking of reading old posts of Henry's, I also found a comment of his which explained a subjective perception I had, which is that high AMD reduces the AFOV so it doesn't "feel" as wide as it should given the spec. I noticed this immediately with the Kowa 6.5x32 BDII, I was expecting to be blown away by a wide, walk-in view, but it didn't feel as wide as I expected. Same thing with the MHG 8x42, the 8.3* FOV is great, but it feels less wide than it is due to the compression of space at the edges.

On the flip side, more pincushion seems to make the view feel wider than it is (the AFOV gets close to the simple mag x fov calculation vs high AMD binoculars which are closer to the "tangent" condition, yes I read Holger's article and tried to refresh my ossified trigonometry skills!).

My feeling is that the reason to get a 7x42 is to have maximum "depth" and "walk in" FOV, so why would I get a design that seems to "fight against" the benefits of a 7x binocular? I like the EDG view in a 10x where I'm just trying to key in on detail at longer range, so I don't care about the "diorama effect", but if I'm going to splurge on a 7x42 I want it to feel natural and 3D.

So I decided to hone in on the Leica, since the Zeiss FL 7x42 is like a rare unicorn on the used market, the UV will have a distortion pattern that will maximize the "3D depth" and AFOV of the image, and I already know I love the color and contrast and build quality of Leicas. And, it just so happens, I just won an auction on eBay for a 7x42 UVHD for a great price, so let's see how this goes! I'm very excited for this one, and if I love it as much as I hope I will, it will likely replace the MHG 8x42 as my "I don't need 10x mag and/or need a larger exit pupil" birding optic.
 

eitanaltman

Well-known member
Yes Eitan, this is exactly my impression of "flat field" and how (largely thanks to Swarovision) it got confused with "less rectilinear distortion". The only thing I would add regarding field curvature itself is that adding field flatteners also introduces complex distortion transitions near the field edge which some can find distracting ("mustache distortion", "Absam ring"). I don't find it as disturbing as the obvious astigmatism of the pre-SF Zeisses for example, but I dislike it and will gladly accept a modest loss of sharpness at the edge instead.

I'm in full agreement -- I don't really care about perfectly sharp edges, it's more of a "nice to have" for me. For real world birding in the field, a large sweet spot (70-80%+ of the FOV) with gradual degradation towards the edges is plenty.

And, honestly, I find that most binoculars are somewhat uncomfortable to try and look at the edges. Since we are on a bit of a Swarovski downer, I will give them credit as having the most "easy" view to actually let your eyes wander around. I had a Swaro 8x30 CL B for a bit, and although I found them to be the most ergonomically horrific high end binocular I've ever tried, the view was just delightful and I've never owned a binocular where it was so effortless to let my eye wander around the FOV, even looking nearly to the edge (and the new SLC 8x30 is sharp practically to the edge).

Even the EDG, which is pretty darn sharp to the edge, does not allow such ease of trying to really stare way off axis. That said, I greatly prefer the EDG formula of leaving a little pincushion and a little field curvature to "soften" the AMD, the view is just lovely to me. (to be fair, the Swaro CL is like this too, just like the SLC it is way less aggressively corrected than the SV models)

As an amusing footnote on the topic of the current "tend" of flat fields + mustache distortion / AMD in high end binoculars.... check out this graphic I found while looking at an old brochure of the Trinovid BA line!

Link (relevant screenshot attached): http://www.company7.com/library/leica/leicabn.pdf

A mere 25-30 years ago, Leica was touting their ingenious decision to employ significant pincushion: "Creates a natural pictorial impression when a binocular is panned across a scene: pin-cushion correction in the optical system of Leica binoculars." What was proudly brandished then would be sacrilegious to admit to now in the Swarovision era! :smoke: :-O
 

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wdc

Well-known member
Thanks Eitan, and everyone else who chimed in on this thread, for taking the time to articulate their thoughts on perceptions of 'flatness' in binocular views. It prompted me to take out a 10x42 EDG and compare it with a 10x42 Noctivid. After spending a few minutes with each, staring at the view outside my studio door, then swapping back, I'm not perceiving what others are describing. I do see differences between the views, but they are contrast and color related (the Noctivid appears brighter, and less warm overall, and the AFOV is larger). In both, I detect a slight 'swimming' of layered elements, such as one group of mid-ground trees against a more distant tree covered hillside, when I pan slowly, that feels like a kind of false parallax. Though when I concentrate on one plane moving in relation to another, it doesn't appear to actually be there. That's about it.

My own personal caveats on this are that I wear glasses, and do not normally have stereo vision, though I DO with binoculars, IF they have a narrow enough IPD to allow my eyes to fuse. In that regard, its highly possible my perception of depth is quite stunted relative to other folks experiences. However, what seems to be the topic at hand isn't a 2 eyed phenomena, it appears to be a spatial distortion induced by a lens prescription, and is observable in a single camera lens/image. Whatever this effect is, it is not apparent to me as something that either implies depth, or subtracts from my perception of it.

-Bill
 

SeldomPerched

Well-known member
Since you have both the EDG and UVHD in 7x42, do you agree with Tobias' assessment of how the Leica feels "wider" and "deeper" even though they have the same FOV? I have been musing over a high end 7x42 for a long time, but after reading Tobias' assessment and also experiencing the EDG view for myself, it made me decide to avoid the EDG version (there was one on eBay recently for around $1100 which I would likely have bought otherwise to try) ...

... more pincushion seems to make the view feel wider than it is (the AFOV gets close to the simple mag x fov calculation vs high AMD binoculars which are closer to the "tangent" condition, yes I read Holger's article and tried to refresh my ossified trigonometry skills!).

My feeling is that the reason to get a 7x42 is to have maximum "depth" and "walk in" FOV, so why would I get a design that seems to "fight against" the benefits of a 7x binocular? I like the EDG view in a 10x where I'm just trying to key in on detail at longer range, so I don't care about the "diorama effect", but if I'm going to splurge on a 7x42 I want it to feel natural and 3D.

So I decided to hone in on the Leica, since the Zeiss FL 7x42 is like a rare unicorn on the used market, the UV will have a distortion pattern that will maximize the "3D depth" and AFOV of the image, and I already know I love the color and contrast and build quality of Leicas. And, it just so happens, I just won an auction on eBay for a 7x42 UVHD for a great price, so let's see how this goes! I'm very excited for this one, and if I love it as much as I hope I will, it will likely replace the MHG 8x42 as my "I don't need 10x mag and/or need a larger exit pupil" birding optic.

I'd agree that the Leica feels wider and deeper than the Nikon 7x42. I haven't had a chance to check this since reading your post, but I have always had the sensation that the EDG had a narrower view. However... the more I use different bins the more I feel that the biggest mistake for my enjoyment of any of them is to go to and fro to compare them; that way I end up dwelling on negative points as well as not using them for what they are intended!

That said, if I decide to thin down a bit, this point you raised would be a good basis for deselection, though in line with what I just said in the previous paragraph it might come down simply to a feeling of how much I like or don't like the overall effect - colour, contrast, lack of glare; and the Nikon is good at lack of glare.

I was interested in your final comment about 8x mag, because since using 7x so much, 8 feels like a high mag without the detraction!

Tom
 

SeldomPerched

Well-known member

AltaVista

Well-known member
Good discussion by Bill and Eitan regarding the terminology used by reviewers!

The term “flat field” has been bastardized in binocular forums to the point that it is effectively meaningless without additional clarifications.
To optics engineers the term “flat field” would naturally refer to field curvature of an optical system (variation of optimal focus across the field of view) and have nothing to do with rectilinear distortion. Period.

It is certainly meaningful and important to discuss the sometimes curious imaging properties of binoculars with respect to geometric distortion, perspective effects, depth of focus, and influence on perceived stereo vision.

What is clear and often overlooked is the variation in the optical system connected to the eyepiece end of the binocular – the human visual system.
The current discussion is a good example of how that can be very different between individuals.

Stephanie
 

dries1

Member
Edg

Andy,

I can't remember if you just recently got yourself an EDG 8x42 - or if you have had one all along. How do you like it yourself? I like my 7x but Tobias originally much preferred the 8x so hopefully it's everything you wanted from it.

Tom

Tom,

Yes I have had the 8X42 EDG for a while. I find in it a very relaxed view, contrast and colors are very appealing. It all seems to mesh with my eyes. I also find the Noctivid provides is a very similar view, different in subtle ways, but close.

Andy W.
 

eitanaltman

Well-known member
Thanks Stephanie, and since you mention the human side of things... one other thing that needs to be mentioned is accommodation / adaptation. What you are used to will greatly influence your perception of something different!

This occurred to me because I received the Leica 7x42 UVHD a couple of days ago. The two binoculars I've been primarily using the past few weeks are the Nikon Monarch HG 8x42 and EDG 10x32, both of which have "flat" views to some degree with a bit of pincushion, transitioning to moderate AMD at the periphery, and minimal field curvature.

But the UVHD 7x42... the view is drop dead gorgeous, but wooo boy it is ALL pincushion, all the way. Like, maximum pincushion, so much so that (irony notice) I was somewhat disoriented by an intense sensation of rolling BOWL. Reverse AMD, as objects "expand" slightly at the edges vs compressing. I've used my wife's UVHD 8x32 plenty and they have a decent amount of pincushion but the 7x42 has significantly more.

What I also found interesting in context of the comments above -- the UVHD 7x42 does NOT appear to have a lot of field curvature. Or, at least, not much more than the Nikons (in fact, I would rate it about equal with the MHG 8x42, with the EDG having barely any). While I'm sure the 7x mag has some impact, the view feels practically sharp to the edge, and I need only a nudge of the focus wheel to bring the edges to nice focus. So it's all about the rectilinear distortion.

I would love to see where some of these models would sit on Holger's distortion graph with k values. One of the most interesting things to me about this graph is the wide variance among models WITHIN a specific lineup; seems one cannot confidently predict how they will react to a particular binocular based on their experience a completely different model in the lineup.

So it's clearly all a balance, both the optics and your eyes/brain.

But a pattern I'm noticing: how bothersome the distortion is seems most closely correlated with how close to the center the wacky stuff starts. I mentioned this above with the Kowa 10x33 (which I found to have uncomfortable panning behavior) the compression/AMD was visible not that far off axis, which meant it intruded into the central visual zone vs being confined more to the periphery. The EDG on the other hand keeps the compression more isolated to the periphery, there's no obvious "warping" of objects until near the edges, so panning feels pretty natural despite the "flatness". The MHG is in the middle, but closer to the EDG; I notice slight "rolling ball" but nothing to bothersome.

Now I'm seeing the inverse phenomenon, and this also correlates with my impressions of the 8x32 UVHD vs the 7x42 UVHD. Both have a good amount of pincushion, but the 7x42 shows more obvious "warping" because it starts closer to the center axis. So perhaps more important than the specific character of the edge distortion is how well maintained the center zone is (in the sense of avoiding visually obvious rectilinear warping until you get out to the periphery).

.........................

Bringing it back to the original thread topic... I've got a bubbling curiosity about the EDG 8x42 now. I am in total agreement with Tobias that the EDG feels like a "Japanese Ultravid", going back and forth between the Leicas and the EDG 10x32 they all have an *extremely* similar "character" to the view, with absolutely top notch contrast and saturation and a touch of warmth (not "yellowing", but real warmth from deep, extended reds) that gives the view a rich, lustrous feel.

Leaving aside physical/ergonomic properties, the only meaningful difference in the views between the EDG and the UVHD to me is the distortion profile. I could nitpick some stuff, but the general gestalt of the views (aside from distortion) is 95%+ the same to me. But I think I've grown to like the more balanced distortion profile of the EDG... BUT also I really love the wide field, incredibly "relaxed" view, and big exit pupil of the 7x42 UVHD. And I think I prefer the more open bridge ergonomics of the EDG / MHG vs the chunky full bridge feel of the Leica.

This makes me wonder if the EDG 8x42 may be the best of both worlds for my tastes. Unlike the Leica UV, the FOV gap between 8x42 EDG and the 7x42 is not that large (7.7 vs 8.0). So only a slight loss in TFOV, offset by a nice gain in AFOV... less pincushion without excessive AMD... a smoother focus knob, a bit more magnification, a bit better CA control, and a more open bridge hold. hmmmmmmm
 

mwhogue

Registered User
Supporter
I'd agree that the Leica feels wider and deeper than the Nikon 7x42. I haven't had a chance to check this since reading your post, but I have always had the sensation that the EDG had a narrower view. However... the more I use different bins the more I feel that the biggest mistake for my enjoyment of any of them is to go to and fro to compare them; that way I end up dwelling on negative points as well as not using them for what they are intended!

That said, if I decide to thin down a bit, this point you raised would be a good basis for deselection, though in line with what I just said in the previous paragraph it might come down simply to a feeling of how much I like or don't like the overall effect - colour, contrast, lack of glare; and the Nikon is good at lack of glare....

Tom"

As far as "wider", both the 7x42 UVHD+ and EDG II have a 420' FoV if I recall correctly but according to the listed specs I found the Nikon has an AFoV of 52.2 vs 56.0 for the UVHD+. I agree this difference is readily apparent - although not bothersome to me - when comparing them.

As far as "deeper", I don't notice any difference between the two and am not sure what "deeper" means here since the DoF of both 7x's is the same, unless it is referring to a different impression of depth of the image some may experience resulting from the "flat field" design of the Nikon vs the pin cushion approach of the Leica (?). If "deeper" is referring to a 3D like effect, the Zeiss FL 7x42 does seem to have a bit more 3D effect than the other two.

Mike
 

eitanaltman

Well-known member
As far as "deeper", I am not sure what "deeper" means here since the DoF of both 7x's is the same, unless it is referring to a different impression of depth of the image some may experience resulting from the "flat field" design of the Nikon vs the pin cushion approach of the Leica (?).

So I assume you didn’t read the preceding posts where it was explicitly discussed what was meant by this line of discussion?
 

eitanaltman

Well-known member
OK, I'm not sure what you're unclear about since the discussion was pretty explicitly about how rectilinear distortion and/or field curvature impact the impression of "apparent" field width and depth.

The comparison of 7x42 EDG vs UV was precisely *because* they are identical on paper on terms of magnification and field of view, yet their differing distortion profiles purportedly gives the Leica a greater sense of both "width" (i.e. greater apparent FOV) and "depth" (i.e. space doesn't feel as compressed towards you).

Tobias referenced this in his 7x42 comparison article (as discussed above) which is where the idea popped into my head first, and then I've observed the phenomenon myself (as discussed above) with my "flatter field" binoculars, so asked Tom if he noticed this since he owned both binoculars in question. It was so obvious to my wife (as discussed above) that she found the EDG view uncomfortable because it gave her the sensation of an image being shoved in front of her face vs feeling like natural space. Others commented on this phenomenon as well and even noted how this is something that's observed with camera lenses, where some lenses give a greater perception of depth whereas others appear to "compress" more distant objects so they appear flatter and closer to the viewer (i.e. what I described above as a "diorama effect").
 

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