Film lenses on dslr

These conversions are giving me a headache) If I put a film camera
50mm lens on a dslr what is the effective focal length? 75mm or 35mm?

quess who wrote:
These conversions are giving me a headache) If I put a film camera
50mm lens on a dslr what is the effective focal length? 75mm or 35mm?

The focal length remains at 50mm. If there is a 1.6 crop (or whatever),
the picture appears to have been taken with a longer focal length lens,
e.g. 75mm. Different DSLRs have different crop factors - some have none
(i.e. they are full-frame).

David

Thank you!

On Thu, 21 Sep 2006 15:57:44 GMT, "David J Taylor"
wrote:

quess who wrote:
These conversions are giving me a headache) If I put a film camera
50mm lens on a dslr what is the effective focal length? 75mm or 35mm?

The focal length remains at 50mm. If there is a 1.6 crop (or whatever),
the picture appears to have been taken with a longer focal length lens,
e.g. 75mm. Different DSLRs have different crop factors - some have none
(i.e. they are full-frame).

David

"quess who" wrote in message
...
These conversions are giving me a headache) If I put a film camera
50mm lens on a dslr what is the effective focal length? 75mm or 35mm?

Focal length is still 50mm, but the angle of view is narrower. For example
on a Canon 30D it would give you an angle of view of a 80mm lens (1.6x).

Think of it this way - imagine the image being projected on a full-size 35mm
film plane as usual. Now imagine in the center of that film is a 22.5 x
15mm rectangle which is what is actually captured. This is what's happening
with sensors smaller than 35mm. The sensor is in the same place as the film
normally would be, but since it's smaller it's only capturing a portion of
what the film frame would (thus the term 'crop' sensors).


Mark

"Mark B." wrote in message
...

"quess who" wrote in message
...
These conversions are giving me a headache) If I put a film
camera
50mm lens on a dslr what is the effective focal length? 75mm or
35mm?

Focal length is still 50mm, but the angle of view is narrower. For
example on a Canon 30D it would give you an angle of view of a 80mm
lens (1.6x).

Think of it this way - imagine the image being projected on a
full-size 35mm film plane as usual. Now imagine in the center of
that film is a 22.5 x 15mm rectangle which is what is actually
captured. This is what's happening with sensors smaller than 35mm.
The sensor is in the same place as the film normally would be, but
since it's smaller it's only capturing a portion of what the film
frame would (thus the term 'crop' sensors).


Try this for a visual:

http://jimdoty.com/Digital/fov_crop/fov_crop.html