• Welcome to BirdForum, the internet's largest birding community with thousands of members from all over the world. The forums are dedicated to wild birds, birding, binoculars and equipment and all that goes with it.

    Please register for an account to take part in the discussions in the forum, post your pictures in the gallery and more.
ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

Owners: How Are Your Leica Noctivids Serving You?! (1 Viewer)

...if the choice is between an optical aberration or no aberration how many of us would decide that the aberration is more natural?...

As an aside, this question and the discussion of glare handling and cine lenses etc brings up the topic of purposeful simulated optical flaws to improve the illusion of cinematic reality/naturalness. I've noticed that in most Pixar movies especially, artificial lens defects are used to enhance realism. I guess this is a topic of much interest in the CGI production community, as there is much discussion of it on the internet.

Here is a link to some simple examples and related
http://www.pixarpost.com/2013/01/imagine-you-at-mu-monsters-university.html

And here is a technical article specifically on the topic of simulating lens flare. Very interesting.
http://matthias.hullin.net/publications/HullinEtAl-LensflareRendering-SIGGRAPH2011.pdf

--AP
 
You want artificial lens flare, check out JJ Abrams work, especially the rebooted Star Trek films - lens flare galore, in fact so much that the special effects people had to go back to some scenes and remove some as it was unwatchable as is.
 
...regarding an image as witnessed through binoculars - there is no applicable hard scientific data to neatly plot, measure and explain away a 'flat field' or 'field curvature'. When anybody speaks of these phenomena in relation to an image viewed through binoculars, they themselves (yourself included) have entered the shifting sands of the descriptive and subjective world. I see nothing wrong with that, but let it be known for what it is.

Rathaus

Even for someone like me using amateur methods it's really not that difficult to "plot and measure" field curvature and off-axis astigmatism in diopters, using star points, grid patterns and the binocular's diopter adjustment. Distortion patterns are also easily photographed.

Once it's established that binocular A has more field curvature in diopters than binocular B, binocular A will never have less field curvature than binocular B no matter who uses it. The distortion designed into the the instrument is also constant no matter who looks through it. I'd rather first determine how much field curvature or astigmatism is actually there and what sort of distortion the instrument has before entering "the shifting sands of the descriptive and subjective world".

Henry
 
Even for someone like me using amateur methods it's really not that difficult to "plot and measure" field curvature and off-axis astigmatism in diopters, using star points, grid patterns and the binocular's diopter adjustment. Distortion patterns are also easily photographed.

Once it's established that binocular A has more field curvature in diopters than binocular B, binocular A will never have less field curvature than binocular B no matter who uses it. The distortion designed into the the instrument is also constant no matter who looks through it. I'd rather first determine how much field curvature or astigmatism is actually there and what sort of distortion the instrument has before entering "the shifting sands of the descriptive and subjective world".

Henry

Henry,

This post contains some of my own personal views and observations.

You state clearly that you would "rather first determine" various data such as 'field curvature' or 'astigmatism' before entering into the 'subjective field'. By the repeated thrust of your blunt and pseudo-technical posts you appear to hold your own observations as being superior to those of us with a self confessed personal and subjective view on these matters. In my opinion, Cherry picking some scientific jingo and then somehow jumping and leapfrogging to a self "determined" observation does not make your observations more valid than anybody else's. It doesn't wash with me in the slightest. Personally, I find such posts of yours on this topic to be grounded in nothing more than the 'pseudo science' of the armchair layperson. If your posts are otherwise (and I hope they are), then I feel you are doing yourself a disservice by not articulating yourself or your methodology nearly thoroughly enough. I will give some examples:

Henry, you claim you can determine 'that binocular A has more field curvature than binocular B' and that this is "not difficult to plot and measure"...and yet you hurriedly and oddly gloss over your all important methodology, depriving other readers from thoroughly scrutinising your process in the same way you scrutinise others. Ultimately, to the informed reader or otherwise, you have articulated nothing of note which differentiates your observations from any other person on this forum.

I strongly suspect that you possess absolutely no valid scientific means of measuring, plotting and recording this process whatsoever. You may 'feel' that you have made some kind of measurement, in the same way that many of us do, but in the process, you yourself will be standing on the ground of mere personal opinion and subjectivity along with the rest of us. Nothing wrong with that, but please do say it as it is.

If I am incorrect, please feel free to set me straight:

What scientific methodology are you using in this process?
What are your points of reference?
What are your formal qualifications pertaining directly to this topic?
Where is your laboratory?
Where do you source your funding?
What organisation supervises your data gathering?
What scientific instruments do you use and to which standards are they calibrated?
How many articles have you published on this topic?
How many 'peer reviewed' articles can you link us to?

You know as well as I, that I have barely scratched the surface in scrutinising your approach to observing, measuring and documenting any relevant data whatsoever.
In the true spirit of science, I'm sure you would only encourage and welcome such scrutiny.


Rathaus
 
Last edited:
Rathaus,


I'm not keen to respond to an ad hominem attack, but I think you can find most of what you want to know by searching old posts of mine. I would start with this list of threads.

http://www.birdforum.net/search.php?searchid=19025518

Henry

Henry,

You made the claim that it is "really not that difficult to plot and measure field curvature", and I am simply asking you to articulate and to explain to us how you might do this, including your methodology.
In order to reasonably justify your statement, I do consider this to be the simplest of requests.

Rathaus
 
Last edited:
Maybe I should have said "possible" instead of "not that difficult". You can find my first efforts in 2005 here:

http://www.birdforum.net/showthread.php?t=48373

You can see that the basic concepts turned into a collaborative effort. Some refinements, including using a camera instead of my eye, came later. Unfortunately, I think those are buried in threads with other subjects. The old 2005 thread should be enough to explain the idea and get you started if you want to try this yourself.

Henry
 
Rathaus.
Your post 66 is completely over the top re. Henry's findings.

Personally I have no formal optics qualifications.
Just a Royal Scholarship.
I have no laboratory.
I have no source of funding, except my piggy bank.
No organisation supervises my data gathering.
I am me, not tied to anyone.
What scientific instruments etc.
The stars, simple mathematics. Published star positions. simple dioptre measurements. Rulers. Mental arithmetic, no new fangled calculators. Vernier calipers.
Many papers and articles published.
I have had quite a few peer reviewed papers, used world wide.

World class optics makers requested permission to use some of these papers. Gladly given.

At least two students pinched my findings and got their degrees. It is called plagiarism.
Another PHD scientist also seems concerned at having copied my findings.

Henry knows a lot more about binocular optics than I do.

Look up the obituary of Horace Dall. A meek person. A genius in the true sense of the word. I think he had no optical qualifications but right at the top of 20th century optics.
He was a world authority also in his professional field.
 
Wow! Possibly the best thread I've seen as justicication to make up ones mind about the values or otherwise of a binocular by looking through it and if you like what you see putting your card in the machine.

LGM
 
Rathaus.
Your post 66 is completely over the top re. Henry's findings.

Personally I have no formal optics qualifications.
Just a Royal Scholarship.
I have no laboratory.
I have no source of funding, except my piggy bank.
No organisation supervises my data gathering.
I am me, not tied to anyone.
What scientific instruments etc.
The stars, simple mathematics. Published star positions. simple dioptre measurements. Rulers. Mental arithmetic, no new fangled calculators. Vernier calipers.
Many papers and articles published.
I have had quite a few peer reviewed papers, used world wide.

World class optics makers requested permission to use some of these papers. Gladly given.

At least two students pinched my findings and got their degrees. It is called plagiarism.
Another PHD scientist also seems concerned at having copied my findings.

Henry knows a lot more about binocular optics than I do.

Look up the obituary of Horace Dall. A meek person. A genius in the true sense of the word. I think he had no optical qualifications but right at the top of 20th century optics.
He was a world authority also in his professional field.

Correct - none of us here have those qualifications, and I see BF as a largely level playing field. I have garnered some of the best information from non technical but earnest and passionate binocular enthusiasts. I see no other evidence whatsoever to view Henry's 'subjective' opinions above most other experienced and earnest folk on these forums. I have no doubt that Henry is a fine chap as are most other folks on BF. That is my view.
 
Last edited:
Wow! Possibly the best thread I've seen as justicication to make up ones mind about the values or otherwise of a binocular by looking through it and if you like what you see putting your card in the machine.

LGM

I agree. If you like what you see, that's a good thing. That's precisely how I purchased the Noctivid. I looked through it for five to ten minutes max...paid and left. One of my best bino buys ever.
 
Rathaus.
Your post 66 is completely over the top re. Henry's findings.

Personally I have no formal optics qualifications.
Just a Royal Scholarship.
I have no laboratory.
I have no source of funding, except my piggy bank.
No organisation supervises my data gathering.
I am me, not tied to anyone.
What scientific instruments etc.
The stars, simple mathematics. Published star positions. simple dioptre measurements. Rulers. Mental arithmetic, no new fangled calculators. Vernier calipers.
Many papers and articles published.
I have had quite a few peer reviewed papers, used world wide.

World class optics makers requested permission to use some of these papers. Gladly given.

At least two students pinched my findings and got their degrees. It is called plagiarism.
Another PHD scientist also seems concerned at having copied my findings.

Henry knows a lot more about binocular optics than I do.

Look up the obituary of Horace Dall. A meek person. A genius in the true sense of the word. I think he had no optical qualifications but right at the top of 20th century optics.
He was a world authority also in his professional field.

Nice post bins :t:
 
Correct - none of us here have those qualifications, and I see BF as a largely level playing field. I have garnered some of the best information from non technical but earnest and passionate binocular enthusiasts. I see no other evidence whatsoever to view Henry's 'subjective' opinions above most other experienced and earnest folk on these forums. I have no doubt that Henry is a fine chap as are most other folks on BF. That is my view.

I have to somewhat disagree with you here. We don't all deserve a trophy for playing. But, I do agree there are some valuable posts by novice optics enthusiasts here. Also, I totally agree with your point that looking through a binocular and deciding if it's satisfactory or not for you is all that should matter in the end. That's how I do it and how many do it here.

However, some here just know a ton more than others and these people (Henry, Binastro and others) are very valuable to the forum. Without their expertise the forum would not be nearly as informative IMHO - their at-home tests are very useful and helpful - experts matter and are appreciated at least by moi.

It's not hard to tell when a birder is at an expert level. Likewise, most of us long-time members know which forum members have expertise in optics.
 
Rathaus,

Could we just all appreciate each others' different contributions and approaches, and use our own preferred source criticism standards privately without attempting to impose them onto others. To me your post read like you might not have a clear idea about the kind of testing Henry does and procedures he uses. Reading some of the threads he linked will show you how simple means can be used to glean lots of valuable information.

Much of the value of Birdforum optics discussions come from fruitful exchange of ideas, experiences, experiments and testing methods & procedures.

Respectfully,

Kimmo
 
Henry,

You made the claim that it is "really not that difficult to plot and measure field curvature", and I am simply asking you to articulate and to explain to us how you might do this, including your methodology.
In order to reasonably justify your statement, I do consider this to be the simplest of requests.

Rathaus

Henry,

With all respect, I still await your proper response to this simple request.

I doubt you will be able to respond appropriately because I believe that you cannot.
- it is my opinion that any attempt to reveal your methodology will show it to be based in descriptive and subjective terminology and descriptive self determined points of reference.

Let it be clear - My point is not intended to denigrate any interesting work or observations which you have made, but to highlight the fact that you, just like everybody else I have read on this forum including myself, are operating from an ultimately subjective viewpoint.

Cheers,

Rathaus
 
Even for someone like me using amateur methods it's really not that difficult to "plot and measure" field curvature and off-axis astigmatism in diopters, using star points, grid patterns and the binocular's diopter adjustment. Distortion patterns are also easily photographed.

Henry
Hi Rathaus;

Henry has already given all the information you need to measure field curvature in the paragraph quoted. All you need is a flat target that covers the field of view and some way to measure diopter (this can be converted to meters if needed).

For the amateur the following are useful for measuring diopter:

The diopter control of the binocular.

Calibrating the focus knob in degrees per diopter or diopter per degree, need a paper scale to read degree or diopter change.

A set of retinoscopy or a set of regular optical trial lenses.

Not really in the amateur realm but readily available (I have a couple) is a professional dioptometer, but these are expensive.

All you need to do is focus the center of the image as best you can then use whatever dioptometer determining device you have to focus the off axis point of interest and note the difference.

I know Henry has used all the above methods, he has a dioptometer but I do not know if, or how much, he uses it. Those are best used on a bench, not really suitable for field use.

Attached are some images I did many years ago for a review of the then new Zen Ray 7x36 ED2.

One good objective/repeatable measurement is worth a great many subjective guesses. Henry does far more of this type of work than I do.

Hope this satisfies your questions.
 

Attachments

  • ST Curves.jpg
    ST Curves.jpg
    107.7 KB · Views: 115
  • ST Average 7x36ED2.jpg
    ST Average 7x36ED2.jpg
    69.6 KB · Views: 130
  • K&E Dioptometer Picture.jpg
    K&E Dioptometer Picture.jpg
    56.8 KB · Views: 121
  • 7680631 1.jpg
    7680631 1.jpg
    29.5 KB · Views: 120
Last edited:
Okay, so let's say one measures the image quality of two binoculars keeping magnification, FOV and other things equal. Binocular A is found to have zero field curvature and B shows positive curvature. Can we conclude that A will be perceived as "flatter" when in use, or that it's a better view? Possibly not.

Being "visual instruments," the two binoculars are clearly intended to be used with human eyes, which have near-spherical biological receptor surfaces (i.e., retinas). The "tests," however, are invariably done using a flat receptor surface (e.g. camera film or sensor). Assuming that the instrument designers' intended optimization was to make the image coincident with the retina, however, then its measured curvature should match the eye's Petzval curvature.* This would be consistent with how forward-looking biological eyes evolved, and would seem to produce more "natural" perceptions.

Looked at it from this perspective, the ideal field curvature for a visual instrument may not be obtained by eliminating it, but rather shaping it to match the human eye. Along these lines I would submit that the Leica NV, like my Swaro 4x42 SLC, probably do an outstanding job matching the image to the eye's Petzval surface without the need for a flattener lens. But, of course, I have no way of verifying this without knowing exactly what curvature the designers had in mind.

Ed

* The instrument's curvature necessarily involves coupling it with an eye model, of which there are several to pick from.
 
Last edited:
Okay, so let's say one measures the image quality of two binoculars keeping magnification, FOV and other things equal. Binocular A is found to have zero field curvature and B shows positive curvature. Can we conclude that A will be perceived as "flatter" when in use, or that it's a better view? Possibly not.

Being "visual instruments," the two binoculars are clearly intended to be used with human eyes, which have near-spherical biological receptor surfaces (i.e., retinas). The "tests," however, are invariably done using a flat receptor surface (e.g. camera film or sensor). Assuming that the instrument designers' intended optimization was to make the image coincident with the retina, however, then its measured curvature should match the eye's Petzval curvature.* This would be consistent with how forward-looking biological eyes evolved, and would seem to produce more "natural" perceptions.

Looked at it from this perspective, the ideal field curvature for a visual instrument may not be obtained by eliminating it, but rather shaping it to match the human eye. Along these lines I would submit that the Leica NV, like my Swaro 4x42 SLC, probably do an outstanding job matching the image to the eye's Petzval surface without the need for a flattener lens. But, of course, I have no way of verifying this without knowing exactly what curvature the designers had in mind.

Ed

* The instrument's curvature necessarily involves coupling it with an eye model, of which there are several to pick from.

Thats a fascinating idea Ed. Thanks for sharing.

On the general question of technical analysis of how a binocular performs optically versus subjective descriptions, I believe we need both and on Bird Forum we get both.

However, I wonder how many of the 151,000 + members that Bird Forum has can make good use of highly technical analyses of binos' optics. For example a description of Swarovski's moustache distortion pattern might make it sound as though the bins would be awful to look through and of course they are the most popular premium bins out there. Nor, when folks ask what bins should I buy for X $/£, or when they want advice about whether bino A is 'better' than bino B do they say, 'make sure your answer is in arc-seconds and includes photos of star tests'. Nor should we forget that many people get tons of nature observation pleasure from the most under-performing of binos.

And yet those technical investigations are vital if we want to know what is going on if a bino has some problem or undesirable characteristic.

I will quote Kimmo here when he says: Much of the value of Birdforum optics discussions come from fruitful exchange of ideas, experiences, experiments and testing methods & procedures.

I totally agree with him that there is room on here and value to be had from all approaches.

Lee
 
Warning! This thread is more than 6 years ago old.
It's likely that no further discussion is required, in which case we recommend starting a new thread. If however you feel your response is required you can still do so.

Users who are viewing this thread

Back
Top