Michael Leuty wrote:
> On 23/04/07, Dr Adrian Midgley (In the office) <[log in to unmask]>
> wrote:
>> being equivalent to an 80mm lens on a full frame 35 mm (film) camera
>
> I am loathe to dispute any statement by Our Ade, but I am told that
> this is not really the case. The position of the sensor means that
> your field of view is more restricted than it would be with a 35mm
> film camera *but* the optics of the lens remain the same, so that you
> will get the same (slight) amount of foreshortening with a 50mm lens
> on a digital camera as with a film camera.
>
It is a topic on which I am yet a grasshopper, however, I will say that
looking at an object, such as a person in front of a wall, with two
cameras;-
my old film SLR with its old 55mm prime lens on it
and my new digital SLR with its new 50mm prime lens on it (IE roughly
comparable lenses[1])
the new one is slightly telephoto and the old one is normal, and the
pictures are different - one is environmental and the other is a
portrait[3].
Clearly the optics of the lens remain unaltered by the back, and I
rarely dispute the nature of reality on Mondays, so let us settle for
functional argument - IE 50mm on full frame is a normal lens and 50mm on
dSLR with a crop factor of 1.6 is a (slightly long) portrait lens. The
Canon 50mm F/1.8 is very nice, and I don't really lust for the Canon
50mm F/1.2 even if I did see it in Geneva airport along with various
other jewels. I like flash only a little bit perhaps because I'm not
good at using it, and I like shallow depths of field, and the extra area
of glass[2] "speed" allows more ambient light pictures, and the added
dilation allows greater isolation of a subject. This applies between
the kit lens and the 50mm/1.8, and between I gather the /1.8 and the
/1.2 which is a big bit of glass and priced accordingly. And I clearly
don't need it.
Portrait lenses diminish noses, or normal and wide angle lenses
accentuate noses, and although my nose is exceptionally fine, I'd rather
have it photographed with the 80mm on real film or 50mm on small frame
dSLR than the shorter lenses. I'm not sure I can compare that effect to
foreshortening.
Old camera
http://osborne.defoam.net/public/images/camera/old/mj_birmingham.jpeg
http://osborne.defoam.net/public/images/camera/old/arthur_sitting_reduced.jpeg
new camera (a picture of Byron Bay lighthouse)
http://osborne.defoam.net/public/images/camera/australia/bbl_l_0383a_reduced.JPG
The Sydney harbour bridge
http://osborne.defoam.net/public/images/camera/australia/IMG_0651.JPG
[1] on completely different mountings or I'd do it with one lens on both
bodies.
[2] strictly, area relative to focal length of course on account of optics.
[3] obviously, I mean from where I chose to stand, clearly one can
close in or step back with either or each lens for a purpose.
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