6 ms·

on a 35mm camera (what used to be standard film) it's 50mm lens is roughly human eye FoV. You really need to know the sensor size to adjust accordingly.

julvo 6y ago
That's right. Here's a handy chart with common sensor sizes: https://en.wikipedia.org/wiki/Full-frame_DSLR#/media/File:SensorSizes.svg https://en.wikipedia.org/wiki/Full-frame_DSLR#/media/File:Se... E.g. on a Canon 450D (crop factor 1.6) the equivalent of a 50mm full frame lens is a 30mm lens
jedimastert 6y ago
I've always heard it was 35mm. Weird. Then again, it's also weird to try and guess what an average perspective would even be, as it's dependent on screen size and distance from face. I wonder how consistent the "arc-length" is between people and devices
- dsego 6y ago
  35 is 50 on a cropped sensor. But I also feel like my vision is closer to 35mm full frame (23 aps-c).
  - throwanem 6y ago
    With no crop factor, 50mm is pretty close to what's "in frame" for me, with my glasses, and 35mm is pretty close to what's "in frame" for my total field of vision. You'd have to defocus pretty hard to make a 35mm lens match what my uncorrected eyes actually see, though...
  - bborud 6y ago
    This conversion doesn't actually make any technical sense. Yes, you can calculate the field of view, but the depth of field, the angles of sight lines etc. are that of a 35mm lens. For an intuitive way to visualize this: look at a few dolly zooms and think about what you are seeing in terms of geometry.
- nicoburns 6y ago
  My understanding is that it's actually ~40mm (or even 42mm). But of course that's not a standard focal length, so either 50mm or 35mm is closest. EDIT: Ah yes, I remembered correctly https://theonlinephotographer.typepad.com/the_online_photographer/why-40mm.html https://theonlinephotographer.typepad.com/the_online_photogr...
  - ghaff 6y ago
    ~40mm isn't that unusual. I have a 40mm pancake lens for my full-frame DSLR and I've had rangefinders with about that fixed focal length and it was pretty common as the low-end of a lot of digital point and shoots.
    - nicoburns 6y ago
      It's true. But it's also not nearly as common as 50mm (or even 35mm) on DSLRs
      - ghaff 6y ago
        Certainly. Before zooms became common, 50mm was absolutely the standard "kit" lens for an SLR. Personally, I always preferred something a bit wider for day-to-day. Of course, most people generally use zooms these days.
roelschroeven 6y ago
> You really need to know the sensor size to adjust accordingly. Absolutely. Focus length without sensor size (or film size) is a meaningless indicator for FOV. But when it comes to a FOV being equivalent to the human eye, surely we should take display size into account as well. A photo made with a 500mm lens displayed at 4"x6" has exactly the same perspective as a photo taken from the same place with a 50m lens, displayed at 40"x60". In fact that small picture is basically the same as the large one cropped to the size of the small one. It's a factor I never see mentioned. The usual explanation is that a "normal" lens gives more or less the same image when we look through the viewfinder as when we look directly, without the camera. But we don't look at photographs through a camera's viewfinder; we see them on our screens, on billboards, on prints.
- steerablesafe 6y ago
  Then you can go all the way and factor in viewing distance as well, then with the physical dimensions of the medium and the viewing distance you get an actual FOV, which better to be in the same order of magnitude as the FOV of the camera when the picture was taken to look realistic.

julvo 6y ago

That's right. Here's a handy chart with common sensor sizes: https://en.wikipedia.org/wiki/Full-frame_DSLR#/media/File:SensorSizes.svg https://en.wikipedia.org/wiki/Full-frame_DSLR#/media/File:Se... E.g. on a Canon 450D (crop factor 1.6) the equivalent of a 50mm full frame lens is a 30mm lens

jedimastert 6y ago

I've always heard it was 35mm. Weird. Then again, it's also weird to try and guess what an average perspective would even be, as it's dependent on screen size and distance from face. I wonder how consistent the "arc-length" is between people and devices

dsego 6y ago
35 is 50 on a cropped sensor. But I also feel like my vision is closer to 35mm full frame (23 aps-c).
- throwanem 6y ago
  With no crop factor, 50mm is pretty close to what's "in frame" for me, with my glasses, and 35mm is pretty close to what's "in frame" for my total field of vision. You'd have to defocus pretty hard to make a 35mm lens match what my uncorrected eyes actually see, though...
- bborud 6y ago
  This conversion doesn't actually make any technical sense. Yes, you can calculate the field of view, but the depth of field, the angles of sight lines etc. are that of a 35mm lens. For an intuitive way to visualize this: look at a few dolly zooms and think about what you are seeing in terms of geometry.
nicoburns 6y ago
My understanding is that it's actually ~40mm (or even 42mm). But of course that's not a standard focal length, so either 50mm or 35mm is closest. EDIT: Ah yes, I remembered correctly https://theonlinephotographer.typepad.com/the_online_photographer/why-40mm.html https://theonlinephotographer.typepad.com/the_online_photogr...
- ghaff 6y ago
  ~40mm isn't that unusual. I have a 40mm pancake lens for my full-frame DSLR and I've had rangefinders with about that fixed focal length and it was pretty common as the low-end of a lot of digital point and shoots.
  - nicoburns 6y ago
    It's true. But it's also not nearly as common as 50mm (or even 35mm) on DSLRs
    - ghaff 6y ago
      Certainly. Before zooms became common, 50mm was absolutely the standard "kit" lens for an SLR. Personally, I always preferred something a bit wider for day-to-day. Of course, most people generally use zooms these days.

roelschroeven 6y ago

> You really need to know the sensor size to adjust accordingly. Absolutely. Focus length without sensor size (or film size) is a meaningless indicator for FOV. But when it comes to a FOV being equivalent to the human eye, surely we should take display size into account as well. A photo made with a 500mm lens displayed at 4"x6" has exactly the same perspective as a photo taken from the same place with a 50m lens, displayed at 40"x60". In fact that small picture is basically the same as the large one cropped to the size of the small one. It's a factor I never see mentioned. The usual explanation is that a "normal" lens gives more or less the same image when we look through the viewfinder as when we look directly, without the camera. But we don't look at photographs through a camera's viewfinder; we see them on our screens, on billboards, on prints.

steerablesafe 6y ago
Then you can go all the way and factor in viewing distance as well, then with the physical dimensions of the medium and the viewing distance you get an actual FOV, which better to be in the same order of magnitude as the FOV of the camera when the picture was taken to look realistic.