50mm - seems 'right'

[ka7197]

50 mm is supposed to be closest to the human eye ...

... which is nonsense.

Closest to the human eye is a full-frame fish-eye. Yet it's not what most people want to use. A photograph will appear normal, or natural, when the focal-length-to-image-size ratio is equal to the distance-of-view-to-print-size ratio. Has nothing to do with 'the human eye,' it's simple geometry instead.

 

[sebastel]

... which is nonsense.

Closest to the human eye is a full-frame fish-eye. Yet it's not what most people want to use. A photograph will appear normal, or natural, when the focal-length-to-image-size ratio is equal to the distance-of-view-to-print-size ratio. Has nothing to do with 'the human eye,' it's simple geometry instead.

wouldn't call it nonsense.
human view is mainly determined by the postprocessing in the brain. the optical component, which has some similarities to a photographic camera, only plays a minor role. so, in general, it's difficult to compare a camera's projected picture to what happens in your brain while "simply" looking.

and, to my experience, the field of view depends on your viewing habits. while you stroll through a vibrant city, you receive and process information from almost a 360° area around you. then your FoV is very wide. when observing little birds on the tree, you focus on a narrow area, and your FoV is more comparable to a long focus lens.

now, someone whose attention lies on a 45° conus will consider the 50mm a natural (on 35mm film or same sized sensors).
different habits, different comparisons.

 

[BernardL]

To me, the natural FOV is that of a 40mm (or thereabouts) lens FF. Other people may have a different perception.

I believe the prevalence of 50mm came about because, for the same relative aperture (f-stop) it is easier to design a 50mm lens than a shorter focal length. See how some designs (Helios-44, Topcon) stretched the definition of "normal" to 58mm to ease the design of a fast lens.

 

[Rob-F]

To me, the natural FOV is that of a 40mm (or thereabouts) lens FF. Other people may have a different perception.

I believe the prevalence of 50mm came about because, for the same relative aperture (f-stop) it is easier to design a 50mm lens than a shorter focal length. See how some designs (Helios-44, Topcon) stretched the definition of "normal" to 58mm to ease the design of a fast lens.

I'd say 35mm comes the closest to taking in what I'm aware of seeing, most of the time. Or to put it another way, when I look in the finder with a 35 on the camera, I usually see the view I was expecting. That's pretty close to 40, and I can make do with a 40 at times.

It's not surprising that 40mm to 45mm or so might feel like a "natural" focal length for some. The true normal lens for a given format has a focal length equal to the diagonal measurement of that format. For the 135 format, that measurement is 43mm. So, plus or minus a couple millimeters, that puts us in the 40 to 45mm ballpark.

I agree that the ease of design had a lot to do with the choice of 50mm as the standard focal length. It's the one that Leitz chose as standard for the first Leicas.

 

[Dogman]

Lots of focal lengths seem right for my eyes, depending on how I consider them. For field of view, I think a 20-24mm seems right. For magnification, 70-75mm looks right. For perspective, I'm in the 45-60mm camp. "Normal" varies for me. Still, I could live with only 45-60mm lenses if I had to.

 

[dee]

The new 15-45 3.5-5.6 lens with the Fuji X-T100 [ on close out ] is all I will ever 'need' but being electric , I cant set it at 35mm, which is a bit of a drag !
I do have the 16-50 and 18-55 but all too slow and bulky when I jut prefer a 50-55 in 35mm.
I tend to go for 45 and drop it down a bit .
Retrospectively , I used an Elmar 50 on the M8 which I guess was around 75mm which was fine with me .

 

[Archiver]

28mm used to be my default favourite focal length. I think this came from my second digital camera, the Canon S70. Wider than my Canon S45 at 35mm, and more in line with how I 'see' naturally.

Canon S70 in 28mm equivalent:

Flinders St at night, via 28mm by Archiver, on Flickr

But I never really got into 50mm until I got the Summicron v5 on the M9, and that became one of my favourite lenses. After that, I got the Zeiss C Sonnar and Voigtlander collapsible Heliar, and love them.

50mm Zeiss C Sonnar:

M9 - Valentino by Archiver, on Flickr

As far as a 'natural' field of view goes, my sense is more like 21 or 24mm in a long aspect ratio, more like 16:9. The Panasonic LX7 at 16:9 is what I find most approximate my sense of vision, or perhaps the double width view of a X-Pan. I'm very big on wide aspect ratios, and love watching movies in 2.39:1 anamorphic aspect ratio.

Zeiss 21mm Biogon in anamorphic aspect ratio:

M9 - Bridging The Sunrise by Archiver, on Flickr


Overall, I like to go out with a 28 and 50. A wide for capturing context, and a normal for a more intimate field of view.

 

[jsrockit]

"Normal" varies for me. Still, I could live with only 45-60mm lenses if I had to.

This range is my normal range too...