[tech] The 40-43mm "natural field of view" (it's NOT correct - proof included)

[@CameraMystique]

00:15 Actual human field of view (nearly 180 degrees) 00:34 The real difference - but it's not real in the image center! *01:36** THE PROOF* 03:17 They are using wrong terminology 04:24 The "real estate photography visual trick" 05:31 The center of an ultra wide angle lens and of a fisheye lens 07:16 Items closer to the lens... 07:44 In conclusion - The 43mm does NOT provide human field of view, so what it is about? 08:37 What to expect from a 43mm lens, and my advice 09:58 The only photographer in the world who...

[@pelicula9779]

Thank you for explaining. Leica marketing team would not be happy to have you tell the truth. But for those who are seeking knowledge your videos are GOLD.

[@CameraMystique]

Thank you for your kind words. Leica doesn't have a problem with that, they had admitted it from the beginning, before the development of the M9. Specifically, that they had a hard time making the edges sharp (their lenses being not telecentric, and not compatible with ordinary sensors, which all require telecentric lenses, meaning lenses with straight vertical chief ray angle throughout the frame). According to Peter Karbe of Leica, *the edges of the Leica digital sensor have angled photosites* to accommodate. But this also makes their sensors incompatible with non-Leica lenses. So, Leica Digital is the most "closed" system out there.

[@stevenjohnson4283]

Have you ever had an eye test guy!!??? I got a box of bandaid/flasters with a clear label on it. Looking straight ahead, pick it up with your hand directly in front of your face 20 to 30 cm (30cm is a foot). While looking straight ahead, now move the box towards your right and there comes a point where you cannot read the box anymore, but there is still a lot more to go to move it to just past your ear. So that portion of your vision in front when you're looking forwards is what you can actually make out in details is 43 degrees, past 43 degrees you cannot read the label even around to the side where your ears are in your extreme peripheral vision. You can read the label beyond 43 degrees, but it hurts and strains the eye. So when you take an eye exam and you should do that every two years, the Optometrist is never getting you to read off of the chart using your peripheral vision, no you are usually reading directly in front and using maybe 30% of your vision area. The only time they go beyond that is when they shine the light into your eyes at greater angles to inspect inside your eyes. The glaucoma test is where you look into a device which has a very large circle and you're supposed to see a little red dot and click the hand trigger when you see a red dot. Now the field of view looking inside is probably wider then your natural field of view of 43 degrees, and last time I took it I started to search around because the area looks wider. Plus your optic nerve has a blind spot where you can't see the red light dots. The glaucoma (Coma) test is a difficult test IMO and I don't like it. Yes we have 180 degrees with peripheral vision, but a simple test here is to as you read my comment, just turn your head to the right while looking at the page, your nose shows up inside your right eye, and the more you turn your head, the harder it is or more uncomfortable it is to read the words, and thats 43%. Turn your head 90 degrees to the right now and try to read my comment using your peripheral vision, and you can't. But why? Your video explains how we have peripheral vision at 180 degrees, and you know how to use a Google. 43mm or 40mm for people with big old hook noses (Roman noses), isn't to do with photography, its to do with what the human eye can perceive - you know PERCIEVE. Can you lay on your back on your couch and watch a movie through your peripheral vision? No way! You have to face the tv straight on, because when your head is on an angle it becomes harder and more strained to watch the movie. So when you go to a photo gallery, do you stand there and view the pictures standing at 90 degrees and viewing them through your peripheral vision? You can't, because the human field of perception is only 43 degrees. Now having 180 degrees of vision is absolutely true and seeing something coming at you in your peripheral vision helps you to protect yourself. If you are being chased in the woods by a bear you can turn your head 90 degrees while you're running, and make out the bears distance behind you, you cannot make out any fine details of what it looks like, just the physical form and how close it is - thats handy in a crisis situation. So when you look at an image from a 43mm or 40mm lens you can perceive the whole image at once. In a wide angle image, your eyes perceive by scanning into areas of the image. Longer than 43mm you can perceive the whole image at once. The 35mm x 24mm full frame has a diagonal of 43mm too. I challenge you to put something to read outside of the 43 degrees field of human view and try to read it for 3 seconds and it starts to hurt your eyes and strains them. Sorry dude, your video is proving you can crop a photos. The human field of vision is 43 degrees, which is the region of unstrained, comfortable and perceptible vision, within the 180 degrees of over all vision - or peripheral vision of 68.5 degrees on the left, and 68.5 on the right. Our eyes are perfected to be used looking directly in front, and not like a chameleon's eyes.

[@CameraMystique]

I have an actual video demonstration at kzbin.info/www/bejne/fIG4cmqcq7SHjc0 time point 3.56 and on, accompanied by a Wikipedia chart of human eye field of view. What you are referring to is *field of immediate attention* (or if you want to call it "field of very clear vision") which varies between individuals. By the way, the so-called 43mm is just the diagonal of the 24mm x 36mm film size (which results to the "normal" projection of a 43mm lens). Full frame is not a scientifically based format or size - it just happened to be the movie film frame size during the time of Mr. Barnack of Leica. If he were to make a medium format camera instead, it wouldn't have been 43mm. Don't tell me that human field of view is determined differently depending on arbitrary camera sensor size... *PS.* If someone would mean "the field within which I can read something comfortably* then that's a lot narrower even than 43mm, it has to be very well in front of me. But when they say "human field of view", without specifying clarity, then they are wrong about the 43mm.

[@CameraMystique]

"Can you lay on your back on your couch and watch a movie through your peripheral vision? No way!" You're right. The focal that would match the narrow field of movie watching would be something like 60mm or so (in full frame). Did you ever hear anyone *specifying* what field they mean by "human field of view"? Do they mean "for movie watching"? Do they mean for "book reading"? (which is very narrow). Do they mean for "walking around in a city"? Do they mean for "enjoying a landscape"? And for what degree of clarity? Nobody specifies in photography what kind of field they mean.

[@sebastiang7183]

This is a very useful clarification.

[@CameraMystique]

In the more recent video "tech Lens Talk" I also have a potential explanation of the Fuji sensor incompatibility, at time 8.01 (kzbin.info/www/bejne/jHmlaJejZ6l4rLM) Because it's not the thickness of the glass cover itself, but the combined thickness of "glass+air", two elements with different refraction indexes.

[@sebastiang7183]

@ I saw that video as well and it’s a very interesting observation. I don’t know enough about it to say anything further but it makes sense at least at first pass with my limited knowledge.

[@TillmanTech]

Thank heaven that you are the only photographer with access to Google! 😉 Thank you for this excellent explanation. And, yes, we have nearly 180º field of vision, but all those degrees are not equal. The fovea only captures about 2º, but that's primarily our "conscious" vision, while the rest of the retina (the peripheral vision) detects motion, shapes, and low-light conditions, contributing to spatial awareness. Thanks again!

[@CameraMystique]

True - copying from an answer I gave below to another viewer: "While the Human Field of View is huge, we rarely pay attention to the sides of our view, unless something is chasing us or surprises us. In reality, as I said in a video about 5 years ago, we pay attention to the center, in an area I called Field of Attention. We had long conversations in this channel about this, and the Field of Attention is about 40-90 or so, depending on the scene..."

[@Mvil9]

I get that ur this video is about the "natural field of view" but i think its replacing one misconception with another.That number comes from somewhere else. 43mm is objectively a "Normal focal length" on a 36x24mm full frame sensor. A normal focal length is defined specifically by the diagonal of the sensor. When the image enlarged and viewed from the distance of its new diagonal, takes up the same amount of space in your vision as the scene did in person. If you hold a 43mm optical viewfinder up to your eye there is little perceivably difference in vision. It doesn't try to compress your entire FOV or bring objects closer. Im sure the words get conflated often which leads to this big misunderstanding. But its something that should be addressed. I think most people are just looking for a good place to start, type in one and the Internet gives another.

[@CameraMystique]

A ha ha... were you spying on my computer? *Because what's you're saying here is part of a large video that's been uploading on KZbin as we speak, and you are absolutely right. You'll get shocked at the similarity of what you say with what I say in the new video.* And what you say "words get conflated" is exactly what I pointed out to this video you watched: they are using the terminology wrongly. It's a common phenomenon. And there's something else too, that some photographic terms are linguistically wrong to begin with. Example: the term "depth of field" was always a bullshit term. More correct should be "depth of focus". But the term "field of view" has been abused to no end. *Maybe we should change to "width of frame" so that all people understand what it is.*

[@HamiltonSRink]

Glad to learn! Thanks!

[@CameraMystique]

If you have time, there's a second part on this topic, the first 10 minutes in the new video: kzbin.info/www/bejne/fIG4cmqcq7SHjc0

[@lionheart4424]

100% agree! I have heard all that hype about 40mm having the "human eye FOV" and being "the new 50mm" nonsense. But then started playing with 35mm and was like "Ehh, I think we are still cropping a bit at this focal length".

[@christof4105]

I never understood this term "natural field of view" thing, for exactly the reasons you said in this video. A lot of people talk about why 50mm is regarded as "normal" but use different reasons why that might be, like magnification, distortion, easy/cheap to produce (50mm 1.8 lenses), rangefinder on vintage cameras was like that etc. I like the 24mm look on canon crop for near subjects, sight seeing etc. but also do landscapes up to 500mm.

[@CameraMystique]

They mean that the proportional distances between objects in the image, is realistic. But what they haven't seen, is that the "disproportional" distances in wide angle lenses are only in the corners. In the center of the image (the center portion representing the image a 50ish would take), they are the same.

[@jessejayphotography]

They are all approximations anyway. Human vision includes two eyes, two lenses, and a brain that does some weird things to process it.

[@GregoryLopez1]

100% with you that the "natural field of view" is bad terminology. I'm a newbie, and hearing this stuff totally confused me, since it's quite obvious that my actual field of view's wider that 50mm (or the supposedly "more accurate" 40-ish mm). Two things allowed me to finally wrap my head around this stuff. The first is that focal length just essentially allows you to crop without a resolution loss. That's all it's doing. The second is that what causes the perspective changes (compression/distortion) is distance from camera to the subject, NOT the focal length. That's why your crop of a wide lens at ~1:30 maintains relative distance between objects compared to a "normal" lens. But isn't there still something to be said for "normal" relationship between objects? If I recall my basic geometry correctly (and maybe I'm not!) 40-ish mm will maintain the relative distance between objects you see with your eye when you take the shot ASSUMING you're viewing the image from a distance that is proportional to how much the final image is enlarged from the sensor. So for example, my Fuji X-trans sensor is roughly 24 x 16 mm. Let's say I enlarged an image I took with Fuji's "normal" focal length of 27mm 10 times to make a final image of 24 x 16 cm. Then, if I held the final image 10 x 27mm = 27cm away from my eyes, the relationship between all objects in the frame would appear as they did to my eyes when I took the shot. So I think there may be something to the "normal" perspective. Like you said, it relates to proportionality between items in the image, not field of view. But it also depends on image size and viewing distance from the final image. Am I off base, or is what i said roughly correct in your view?

[@CameraMystique]

They are using "field of view" wrong to begin with. Human vision is very wide, 43mm is narrow. As far as the rest, "proportionality between items in the image" (and proportional distances between them) is correct. Image size has nothing to do with it.

The only way we could find a "natural" FOV, is by giving people a bunch of images, and see what distance they hold them from their eyes. From that distance, with the size of the picture, we could calculate the "natural" FOV, just like if that print was a window into an other reality. With enough samples, we could get a rough estimation on what FOV we like to look at pictures, and copy that with lens. But again, it depends on so many things, each person is different, each photo is different.

[@CameraMystique]

True, that's a different topic though, which I covered in fragmented sections in older videos. Maybe I need to make a concise, complete new video on the topic.

[@moritzberger4898]

DXO PhotoLab 8 and ViewPoint 5 offer 2 flavors of focal-lengh induced ('geometric') distortion (beyond the 'optical' characteristic of individual lenses). Worth checking out - they have trials and Black Friday is tomorrow ...

[@CameraMystique]

Yes, I have seen this. Thanks for reminding me.

[@brugj03]

I`m a real wide angle photographer my 16 -35 is my favorite lens. I think wide is the natural field of view of the human eye sight. I consider everything above 24 already to narrow.

[@CameraMystique]

Here's the real wide photography (if you don't want to "panorama" etc): kzbin.info/www/bejne/b32YgGOZadiNl9U

[@brugj03]

@@CameraMystique That`s exactly how i do it myself. Cinemascopic photograpy with wide angel lens. Voigtlander 10mm for example.

[@lightbit553]

For APS-C you can use 28mm to get same natural perspective as 43mm on full-frame.

[@gamebuster800]

The focal length or field of view of a captured image means nothing until the image is observed. While human vision might be 180 degrees, the observed photo is not (unless you strap a VR box on your head). If one cares about "the correct field of view", one should consider the field of view of the image as it will be observed. The wider the lens, the wider the FOV should be when observed. If you're going to hang up a smaller frame on a wall, it is likely better to put a photo on there with a longer focal length (85mm headshot). If you're going to make a large print viewed up close, a wider focal length is definitely better. Imagine going to the movies and the movie shows a 200mm-like image close-up of a person. It would look really unual - uncomfortable even. Do the same thing when targeting an old home setup with old small 4:3 TVs, and close ups of people are "normal" because the target FOV is tiny. I also think this is why wider lenses are becoming more popular. Displays are getting bigger, so it is more normal to use wider focal lengths. People are also used to seeing themselves on 24mm-ish cameras by taking selfies or using their phone, so one should really consider 24mm to be "the new normal". Not because it matches some magic FOV, but because it matches the focal length people are used to.

[@CameraMystique]

True - but my point in this video was to debunk the videos and articles which say that "43mm resembles the human field of view", which is blatantly incorrect. You are correct about most of the rest, but as far as wide angle shots are concerned, unfortunately the opposite is happening, and many Hollywood directors complain that the "good old establishing wide shot has been lost". *The reason is that more and more people are watching movies and pictures on Phones and Tablets.* Take even this channel for example... my videos and photographs are optimized for screens 24" - 32", yet 55% of my viewers view the videos on Phones (a terrible experience for this kind of content). KZbinrs seeking more viewers, are optimizing their content for phones. As far as a 200mm lens, you can use it for landscapes too, if you move far enough back. Many of the images in my channel that look like "35-50mm shots" were actually taken with 135mm or 180mm focals. And others that look like "50", were taken with a 28, with the sides cropped out.

[@gamebuster800]

@@CameraMystique I didn't disagree with anything in your video, I just felt the need to add my thoughts on the topic.

[@CameraMystique]

@@gamebuster800 Yes, as long as my main point got through. Because the error of these publications is blatant! It's as if these people have no peripheral vision.

[@gamebuster800]

@@CameraMystique Yeah I always considered the "50mm is the perspective of the eye" posts/videos a silly argument. Maybe people that write these things either don't think for themselves, or have severe tunnelvision.

[@eugeneBai]

Thanks a lot for sharing your knowledge! 🙏 Very interesting!

[@davidellinsworth3299]

I didnt hear if you mentioned this in the video or not (forgive me if you did but there were a lot of distractions around me whilst watching) but the majority of the human visual FOV is bokeh, which likely helps us "correct out" those distorted edges. Almost like we have a greatly exaggerated field curvature?

[@CameraMystique]

True, but the video would have become too detailed and too "out of topic". The main point of the video was to debunk all those other videos and articles saying that 43mm is "human field of view", which it is not. I didn't even expect so-called professional publications to make such a blatant error.

[@davidellinsworth3299]

@CameraMystique yes all true in the video. Many people (in fact, most) describe 43mm as human FOV, the obvious example of error being how you can see people sneaking up alongside you if that is the case, whereas you don't in a viewfinder

[@CameraMystique]

43mm is very narrow. If you practice, you can determine the FOV with your arms extended in front you in various angles. For 43mm focal, the Field of View is actually about 43 degrees only (for 50mm lens, it's 39.6 degrees). This is VERY NARROW, compared to human vision of almost 180 degrees (realistically about 165).

[@CameraMystique]

They got a fun table here: www.nikonians.org/reviews/fov-tables

[@poppiestuff]

Do you have a favorite lens?

[@CameraMystique]

It's uploading now, and there are detailed responses to this and to another one of your comments. Lots of dead time in between making bread loaves for tomorrow.

[@fuji5339]

maybe in the city ...a 35 to 50 mm lens is great but for me...I live by the ocean...and I like super telephoto lenses to see ships far away on the water....huge ports, islands.

[@CameraMystique]

Of course... the point of this video was to debunk the myth of "natural field of view" of the 40-43mm lenses. Because the gear sellers will find any reason to appeal to those addicted in lens collecting.

[@fuji5339]

I never liked wide angle lenses...only use them when I am in a small place where I cannot step back to get everything in the frame that I want...so I switch to wide angle to get the picture but I never like the distortion at the edges...looks like a low quality picture. I always preferred the look of pictures taken with telephoto lenses...the way portraits look with those lenses and how they bring the background closer.... also wildlife looks good only when you fill the picture with it...and you rarely can do that with a 50 mm or less. for me...90 mm is my regular lens instead of a 35 or 50mm. and I have long lenses...even a nikon p950 with 2000 mm equivalent lens.

[@CameraMystique]

So you like being a close observer/very attentive. While the Human Field of View is huge, we rarely pay attention to the sides of our view, unless something is chasing us or surprises us. In reality, *as I said in a video about 5 years ago,* we pay attention to the center, in an area I called *Field of Attention.* We had long conversations in this channel about this, and the Field of Attention is about 40-90 or so, depending on the scene, with the Field of Close Attention between 90-150mm.

[@Chips-Lab]

This is not scientific but I do believe our eye see in 85mm but with a crazy large sensor to get this large field of view

[@CameraMystique]

I responded to this in the new video... hope you'll like the answer and clarification.

[@KarloFio]

Very particular effort, thank you! But, cropping down "doesn't" mimic a different angle of view, no! It only brings the far away subjects closer which represents the binocular effect and nothing else. 42.5 mm is the angle of view of our both eyes, peripheral view depends on several factors and it is deeply depending on our state of mind, our priorities in the given moment... Peripheral view is a sign of our momentary acceptance of security or fear or ignorance or love or respect or simply wishing to collect everything of that precious and rare moment, it is deeply emotionally influenced and can not be measured. At the end, the truth remains that our eyes are seeing only in black and white, the colours are created somewhere else in the brain, that's why some people can't recognise colours or have sever problems with the night vision. If I want to see, capture the moment I will concentrate on the subject, if not then everything is welcome to "join" my vision, the angle of view I am prepared to notice... But, 42.5mm is 42.5mm and it will always be 42.5mm, crop or no crop it is 42.5mm... The only issue is how close are you prepared or willing to stay in front of your object of interest. And then, people do mix up the angle of view with the focal distance, it is NOT the same!!! As I said, croping DOESN'T change the angle of view, it only brings distant objects closer, like the prescription glasses 😂Everything else is nonexistent, keep up the good work 👍

[@CameraMystique]

I didn't say that cropping changes the angle of view. I was just pointing out the error many publications made by saying that 43mm is equivalent "human field of view". It's not. I'm not sure that most of them even know what "field of view" is.

[@KarloFio]

@@CameraMystique Well, 42.5 or even 43mm is certainly representing the "human field of view" concerning both of our eyes as organs in "stereo" mode. It is measurable. The eyes don't "see" anything without the collaboration of our brain, similar to the lens which can't do anything without the camera but there are sensors in different sizes! With best regards 🙂

[@CameraMystique]

@@KarloFio Human field of view (measurable) with both eyes is almost 180 degrees coverage (in "stereo mode" as you say). If you hold your arms open on the side and look straight ahead, your peripheral vision almost captures the palms of your hands. On the other hand, the 43mm lens covers only about 42 degrees horizontal.

[@KarloFio]

@@CameraMystique You are, sorry but terribly wrong because you are counting the peripheral part in! I mean, it's wrong because the quality is degrading towards the edges and at the same time we could very well bump into the tree in the front of us because we believe in 180 degrees and don't look where we are going 🤣🤏 I mean, we are no chameleons and yes, maybe Leica knows the business, or not🤔

[@CameraMystique]

@@KarloFio PS. Unless you mean the "field of attention", which is the area in front of us (a narrower field), since we tend to ignore what happens in the peripheral vision, unless there's some motion or other warning sign. Visually the eyes capture of huge area, while the field of our immediate attention, depending on your surroundings, is narrow. People admiring a wide landscape from a mountain top "activate" more of it, resulting in about 90 degrees attention, while the same people watching Television narrow it down to only a few degrees and ignore the rest.

[@ChrisThe1]

43mm is "natural" because when you have a camera with a 1.0 magnification viewfinder it looks the same as not looking through the camera. Whole thing's irrelevant when looking at photos

[@CameraMystique]

The sense of depth is the same (proportional distance between subjects) - but not the "width" of the frame. I have a video example in the first 10 minutes of kzbin.info/www/bejne/fIG4cmqcq7SHjc0