Many people assume that a 50mm lens on a 35mm camera is the normal focal length and the best choice. They do not understand the history of the 50mm focal length lenses on 35mm cameras. With rangefinder cameras, pre DSLR cameras, the maximum focal length for the cameras manual focus controls was 50mm. Anything longer required a special framing adapter that mounted on the hot shoe on top of the camera.
Photographers with that focal length lens would usually clutter their images with all that was in the frame around the subject, hence the advice that one should get closer (crop in the field) to have stronger images. The option of a 105mm focal length lens coincided with the arrival of SLR cameras. Asahi produced the first SLR camera with an instant return mirror in 1954 which evolved over the next decade. It was the SLR that enable the use of telephoto lenses.
If one examines the images from most photographers the inclusion of visual debris in them is common as they see the subject and ignore everything else in the frame. Having a post appearing to sprout from the top of a subject's head is one such result. One also sees many images with a shorter than 50mm focal length lens that results in perspective distortion of subjects as body parts closer to the camera appear disproportionately large (feet, hands, noses) which is not flattering for the individual.
In terms of what the mind's eye perceives in a scene a 105mm focal length lens provides the most accurate capture and cropping of a scene. With a 24-120mm or similar zoom range a person can explore this for themselves and see the results.
I suspect that the reason that 50mm was declared the 'normal lens' way back in the 1920's through the 1950's is that 50mm was the widest angle lens that could be made with 1. decent picture quality and 2. at an affordable price point. It is my suspicion that IF Leitz and Zeiss and the others that went into 35mm (8 perf) cameras at that time could have made and offered a 35mm lens of useable speed, quality and acceptable cost, they would not have gone with 50mm.
Just or fun, one can make argument for almost any focal length to be a normal lens.
Full frame fisheye: that's how the human eye actually sees before brain-correction of straight lines.
24mm: Most of what one sees in one glance is picked up by a 21 or 24mm.
35mm: The longest lens that gives the impression of deep focus.
90 or 100mm: Most peoples' visual attention is on an area that this field of view provides.
180mm: Same as above
500mm: The zone of true detail seen by the human eye is tiny, something like 1/2 of one degree. A super tele comes closest to this field of view.
Why reinvent the wheel again? The focal length that roughly corresponds to the diagonal of the negative has always been considered the standard focal length. So, one might ponder why 50mm has prevailed in 35mm format and not 43mm. Whether that's of any use to anyone is another question.
I've used 50mm on a full frame camera... I look thru the viewfinder and look at the scene with my other eye. The framing is the most similar at about 50mm for full frame or equivalent. Anything wider or longer seems different from what my eye sees. This seems to be a common thread with most photographers but not everyone agrees.
I actually personally dislike 50mm, I like 35mm to 40mm best even tho it's slightly wider than my eye's view field. I find that I can walk then immediately take a pic with 35-40mm while with 50mm I must step back once or twice to get the photo I want. I oddly don't suffer from this constant step back problem with 75mm or 85mm or longer...
I learned over 50 years ago that a normal focal length was approximately equal to the diagonal of the film. That has nothing to do with the subminiature (135) format and also applied to 4x5, 8x10, etc. For 35mm the normal FL would be 43.3mm.
Nifty Fifty wrote:
Why reinvent the wheel again? The focal length that roughly corresponds to the diagonal of the negative has always been considered the standard focal length. So, one might ponder why 50mm has prevailed in 35mm format and not 43mm. Whether that's of any use to anyone is another question.
Because Oskar Barnack liked the field of view for hiking.
The first successful 35mm stills Cameras were the Leica's, which came with 50mm lenses. The Leica 1 was designed by Barnack in large part as a lightweight camera for hiking.
Since Leica had a 50mm lens, Zeiss and others copied it as the default option and it became the default by inertia.
mawz wrote:
Because Oskar Barnack liked the field of view for hiking.
The first successful 35mm stills Cameras were the Leica's, which came with 50mm lenses. The Leica 1 was designed by Barnack in large part as a lightweight camera for hiking.
Since Leica had a 50mm lens, Zeiss and others copied it as the default option and it became the default by inertia.
This comports with the history as I have read it. However, Barnack had no useable 40mm, 35mm, or 28mm to choose from.
My personal speculation: I submit that IF Barnack or others with access to the early Leicas had a choice, they might not have picked 50mm as a universal "normal" lens. 35mm makes more sense....but we'll never know!
To my eyes a full frame FX shot from a 50mm has "normal" near to far object distance sizing whereas shots from a 35mm make the room appear larger than it is. And, shots from a 100mm compress near to far perspectives.
elkhornsun wrote:
In terms of what the mind's eye perceives in a scene a 105mm focal length lens provides the most accurate capture and cropping of a scene.
I strongly disagree there. I no way do I perceive anywhere near 100mm to be my general field of view. If anything, 50mm feels a touch too narrow, but it isn’t far off. 40mm probably more accurate to my eye for a general area of focus, though the periphery and what I generally “feel” for inhabiting a space is closer to 20mm.
Keith B. wrote:
This comports with the history as I have read it. However, Barnack had no useable 40mm, 35mm, or 28mm to choose from.
My personal speculation: I submit that IF Barnack or others with access to the early Leicas had a choice, they might not have picked 50mm as a universal "normal" lens. 35mm makes more sense....but we'll never know!
The 50mm Anastigmat was designed for Barnack's project, which had been in development since 1913, with the lens being designed in 1920. I'm sure that if Barnack wanted a wider lens, he could have had Berek design one instead of that 50mm.
Most notably, the Ur-Leica (Barnack's original prototype from 1913) in fact was fitted with a Mikro-Summar 42mm f/4.5 lens that was replaced by the purpose designed 50mm f3.5 Anastigmat in the production model. That 42mm is very close to being a true normal for the 34x24mm frame on early Leica's.
So Barnack did in fact have a wider option available (or to have something else designed) and chose to have a 50mm designed for the original Leica.
50mm cemented its position because back then (ah, the halcyon days of the 20th century) camera users took photos of people. It used to be estimated around 90% of what they shot were of fellow human beings. Now it's more like 5%, if that. And it's easy to design and produce 50s. cheaply, as small light lenses.
Anyway, many prime users will enjoy normal looking portraits from 28mm to 55mm (personal opinion, based on so long). Anyone who sees longer as 'normal' does not see on-axis compression well.
Nearly all of them breathe a fair bit, so add 5-10% to the stated focal length for near-focus shots. My Simera 28mm is more like a 32mm at close distances, and that is a good aberration to have in this instance, IMO.
You can easily become quickly accustomed to any regular FL, so much it can appear 'normal'. That's a trap for prime users, so try and swap them around each session. I've heard of people shooting an entire trip with a 21nn or 24mm.
I just noticed this thread. It's a subject I pondered for purely theoretical reasons for decades. Some thoughts, in no particular order:
The history of how, when, or why lenses were developed has little pertinence except that we become used to seeing pictures shot with whatever lenses were used when they were taken.
The technical differences between a rangefinder and SLR-type camera might affect what a photographer can do reliably but the finished result is the same once it is committed to film. If a shot has a light pole sticking out of someone's head, it isn't the lens's fault. And with print cropping or digital editing, edge clutter can be eliminated and the subject enlarged. The only question is whether the subject has acceptable resolution.
The diagonal of the frame is a nice, concise metric (metrics are always welcome) but it has no special theoretical significance. If the "standards" had been chosen as 16:9.5 instead of 16:9, or 4.3:2.95 instead of 4:3, or whatever, the diagonals would be different but the captured images would be the same. Only the available frame area and shape would be different.
Perspective is determined by the camera's position w.r.t. the subject(s), not the lens. All the lens does is capture the view from the camera's perspective onto film in an image of a certain size. Were you to blow up a wide-angle picture or shrink a telephoto picture (both taken from the same location) so that the subjects were the same size, the perspective would be the same between them.
When someone looks at a picture, either printed or on a screen, it is usually at a distance from the eye that falls within a certain convenient range. That range determines the viewing angle for the typical subject of interest. Hold the picture closer and the viewing angle gets larger but the perspective in the picture itself doesn't change. You can view someone's face close-up, much closer than in real-life (except when kissing), but you don't hold most pictures that close for general viewing.
So the "normal" image size will be whatever viewing angle matches the viewer's typical real-life viewing angle of that subject for any given perspective, i.e. for the camera's position. If we were used to viewing pictures from twice as far away we would need images twice as large for the same perspective, and thus a longer lens for the same shot. It's a question of picture-viewing distance as much as camera to subject distance.
Perhaps we shouldn't discuss what a normal focal length is (since that has essentially been defined since time immemorial), but rather who has chosen which focal length as their personal standard focal length. That's a completely different thing and depends on a person's way of seeing, their personal preference for certain perspectives, and, of course, their preferred subjects. As far as I'm concerned, everything speaks in favor of 50mm. The angle of view corresponds pretty closely to what I consciously(!) perceive as the field of view in real life, and when I look at many, many pictures with different focal lengths, it turns out that the ones I find most pleasing were usually taken at 50mm. But as I said, different people have different sensibilities and should therefore find their own standard focal length. Whether that will be a normal focal length, a telephoto lens, or a wide-angle lens remains to be seen.
Nifty Fifty wrote:
Perhaps we shouldn't discuss what a normal focal length is (since that has essentially been defined since time immemorial), but rather who has chosen which focal length as their personal standard focal length.
elkhornsun wrote:
In terms of what the mind's eye perceives in a scene a 105mm focal length lens provides the most accurate capture and cropping of a scene.
If 105mm is what your eyes see as normal I'd go see an opthalmologist. I'm surprised you can use a keyboard to type.
I think I get what you mean, it is probably the field of view your eye concentrates on even though the total view is much wider. But regardless, 105mm is like tunnel vision without the context around it. Perspective becomes compressed and flat and unnatural vs what our eyes see.
The point is that everyone perceives differently. You only see details in the very small fovea anyway.
I often see through a tele viewpoint, like binoculars. That's because most species don't let you get close or they may be in the air or water.
It seems like there is a photographically cultural bias that photos should be of humans in some grungy old city.
And if you need to do more than briefly glance at a keyboard to type, that's another issue.
