Spring 2012

Spring 2012
by ani

Submit your Photo
Hall of Fame

Please participate in Meta
and help us grow.

Photography Stack Exchange is a question and answer site for professional, enthusiast and amateur photographers. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Focal length is the only factor that decides whether a lens is described as being normal or wide angle.

Below which focal length are lenses considered to be wide angle? Is this focal length the same for all types of camera (full frame, APS-C, etc.)?

Also, from the point of view of designing/building a lens, do normal lenses and wide angle lenses differ other than in focal length?

share|improve this question
Check out How can a 24-70mm and a 10-22mm both be "wide angle" lenses? — I think the answers there should cover your question. – mattdm Aug 15 '12 at 18:33
Also, photo.stackexchange.com/questions/327/…. For construction I think you should really open up a separate question. – dpollitt Aug 15 '12 at 18:53
@dpollitt Can i edit this question to make it only for construction? – vivek_jonam Aug 16 '12 at 4:38
On differences in construction: photo.stackexchange.com/questions/4487/… – mattdm Aug 16 '12 at 11:48
up vote 8 down vote accepted

Wide angle is in comparison to 'normal'. On a full frame camera normal is considered to be 50mm and wide angle is less than 35mm.

Using these numbers we can determine that the accepted ratio for wide angle is less than 0.7 times that of normal on a given format. On APS-C the normal focal length is 35mm, making wide angle start at 23mm.

Most SLR cameras have a mount to film plane distance of about 40mm. Any lens with a focal length less than this distance requires a reverse telephoto group to extend the distance between the lens and the focal plane. On a full frame sensor a normal lens can be much simpler than a wide angle lens since a normal lens (50mm) has a greater focal length than the mount to film plane distance (40mm). On APS-C the normal lens (35mm) has a distance less than the mount to film plane distance, so there is no fundamental differences between the construction of a normal and wide angle lens.

Source: Wide Angle Lens on Wikipedia

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.