Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Zoom range regarding corrected distortion
#4
A 12mm lens is a 12 mm lens.



There are two things to regard.



The focal length does not describe the field of view, all on its own. A 14mm corrected lens gives a MUCH less wide view as a 14mm fisheye lens. A lens that is not well corrected will give a wider view than a well corrected lens.



As such, you can assume that a corrected photo from a not well corrected lens gives about the same field of view as a photo taken with a well corrected lens. The Olympus 12mm lens will probably be a 12mm lens, and the view angle given by the manufacturer will probably be based on the in-camera correction. Lens manufacturers anyway are very creative sometimes with published lens data...



The other thing to regard is that focal lengths are given for infinity focus. Especially with zoom lenses with big zoom ranges, like the 18-200mm type you mentioned, the focal lengths at close focus can be a lot different. Most 18-200mm lenses do not reach past 135mm at close focus, for instance. This is called focus breathing.



Another, more complex, thing to consider is that field of view and focal length are not 100% "linked". If the focal length remains the same (iow, the focal length does not "breath"), the field of view will get more narrow the closer by you focus.
  


Messages In This Thread
Zoom range regarding corrected distortion - by Shamrock - 10-05-2012, 06:35 PM
Zoom range regarding corrected distortion - by Shamrock - 10-06-2012, 09:45 PM
Zoom range regarding corrected distortion - by Brightcolours - 10-07-2012, 09:15 AM

Forum Jump:


Users browsing this thread:
1 Guest(s)