The eye and the lens

"celcius" wrote in message ...

I don't know whether I was clear enough but I wasn't referring to field of view, which I understand is much wider with the naked
eye that even with a 24mm lens.
When I reflected upon this, I was aiming at a stop sign and such other items. Looking through the 70mm lens, the stop sign was a
bit smaller than looking at it with the naked eye. I didn't have my glasses on and wasn't interested in how clear I could see it,
simply the overall size of it.
In your last post, You said that "75mm matches the perspective I see with bare eyes". This verifies to almost a iota what my
experience was (a tad smaller with a 70mm, of course about the same size with a 75mm. Can we say then, that the size of an object
as seen through the naked eye is the same as with a 75mm lens (with a full size sensor)?
Regards,
Marcel

NO! Again, as many now have pointed out, the magnification as defined
by the camera designer establishing what focal length lens "matches" the
VF. It could be anything - 50mm, 72mm, 43mm, 107mm, whatever...
The original source of set-ups was the early Leica rangefinder, which,
having a narrower body depth, made the use of a good symmetrical
50mm f2 practical (longer than the 35mm format 44mm diagonal, but
still a good compromise). With that established, the VF "window" or
detachable VF could be made to match reasonably closely, giving
nearly 1:1 relationship with the direct view. With much wider or longer
lenses, this becomes impractical, but with some pro level Nikons, there
were VFs that featured nearly 1:1 viewing with a 50mm lens, 100%
image area coverage, and high "relief" permitting good viewing distances
between the eye and the VF (sometimes with accessory "sports finders").
Also, as others have pointed out, cheaper cameras tend to have worse
VFs in the above respect (and also in sharpness, brightness, and freedom
from linear distortion).
--DR

"David Ruether" wrote in message
...

"celcius" wrote in message
...

I don't know whether I was clear enough but I wasn't referring to field
of view, which I understand is much wider with the naked eye that even
with a 24mm lens.
When I reflected upon this, I was aiming at a stop sign and such other
items. Looking through the 70mm lens, the stop sign was a bit smaller
than looking at it with the naked eye. I didn't have my glasses on and
wasn't interested in how clear I could see it, simply the overall size of
it.
In your last post, You said that "75mm matches the perspective I see with
bare eyes". This verifies to almost a iota what my experience was (a tad
smaller with a 70mm, of course about the same size with a 75mm. Can we
say then, that the size of an object as seen through the naked eye is the
same as with a 75mm lens (with a full size sensor)?
Regards,
Marcel

NO! Again, as many now have pointed out, the magnification as defined
by the camera designer establishing what focal length lens "matches" the
VF. It could be anything - 50mm, 72mm, 43mm, 107mm, whatever...
The original source of set-ups was the early Leica rangefinder, which,
having a narrower body depth, made the use of a good symmetrical
50mm f2 practical (longer than the 35mm format 44mm diagonal, but
still a good compromise). With that established, the VF "window" or
detachable VF could be made to match reasonably closely, giving
nearly 1:1 relationship with the direct view. With much wider or longer
lenses, this becomes impractical, but with some pro level Nikons, there
were VFs that featured nearly 1:1 viewing with a 50mm lens, 100%
image area coverage, and high "relief" permitting good viewing distances
between the eye and the VF (sometimes with accessory "sports finders").
Also, as others have pointed out, cheaper cameras tend to have worse
VFs in the above respect (and also in sharpness, brightness, and freedom
from linear distortion).
--DR
Thanks for your patience, David!
I've re-read all the posts and finally understand.
Cheers,
Marcel

On Tue, 24 Nov 2009 10:31:34 -0500, "David Ruether"
wrote:
:
: "celcius" wrote in message ...
:
: I don't know whether I was clear enough but I wasn't referring to field of view, which I understand is much wider with the naked
: eye that even with a 24mm lens.
: When I reflected upon this, I was aiming at a stop sign and such other items. Looking through the 70mm lens, the stop sign was a
: bit smaller than looking at it with the naked eye. I didn't have my glasses on and wasn't interested in how clear I could see it,
: simply the overall size of it.
: In your last post, You said that "75mm matches the perspective I see with bare eyes". This verifies to almost a iota what my
: experience was (a tad smaller with a 70mm, of course about the same size with a 75mm. Can we say then, that the size of an object
: as seen through the naked eye is the same as with a 75mm lens (with a full size sensor)?
: Regards,
: Marcel
:
: NO! Again, as many now have pointed out, the magnification as defined
: by the camera designer establishing what focal length lens "matches" the
: VF. It could be anything - 50mm, 72mm, 43mm, 107mm, whatever...
: The original source of set-ups was the early Leica rangefinder, which,
: having a narrower body depth, made the use of a good symmetrical
: 50mm f2 practical (longer than the 35mm format 44mm diagonal, but
: still a good compromise). With that established, the VF "window" or
: detachable VF could be made to match reasonably closely, giving
: nearly 1:1 relationship with the direct view. With much wider or longer
: lenses, this becomes impractical, but with some pro level Nikons, there
: were VFs that featured nearly 1:1 viewing with a 50mm lens, 100%
: image area coverage, and high "relief" permitting good viewing distances
: between the eye and the VF (sometimes with accessory "sports finders").
: Also, as others have pointed out, cheaper cameras tend to have worse
: VFs in the above respect (and also in sharpness, brightness, and freedom
: from linear distortion).
: --DR

I had a Nikon SP, and its viewfinder showed the scene at 1:1. You could leave
your left eye open, with no mismatch between the size of what it saw and what
your right eye saw through the viewfinder. The viewfinder was sized to match
the FoV of a 35mm lens, with additional frame lines for (IIRC) 50mm, 105mm,
and 135mm. (I had a 28mm lens, which required an auxiliary viewfinder to be
mounted in the hotshoe.)

Bob