Prime Lens Query!!

[stryvya]

Hi, Am i right in thinking that a EF 50mm Lens on a Crop Body will give you 80mm Focal length but a EF-S 50 mm Lens will give you 50mm??

 

[hyeongsoong]

No. They all give the same fx equivalent of 80mm.

 

[wardy07]

Hi, Am i right in thinking that a EF 50mm Lens on a Crop Body will give you 80mm Focal length but a EF-S 50 mm Lens will give you 50mm??

No sadly not - they are the same as far as the crop factor goes.
EF-S lenses are specifically designed for crop sensor camera but the major difference is in they are optimised for a smaller sensor & mirror which the 1.6 crop cameras have.To obtain the equivalent of 50mm on a 1.6 crop is to get a 30mm ish (48mm with crop added) lens.

 

[chris malcolm]

The focal length of a lens is the distance between the centre of the lens and the position behind it where a sharp image of a distant object is formed. It doesn't change no matter what kind of camera body you put it on. Different sensor sizes will produce different angles of view. A 50mm lens on a 1.5 crop sensor will produce the same angle of view as a 75mm lens on an FF sensor, or a 150mm lens on a 0.5 "crop" sensor, e.g. in an MF camera body. The focal length never changes. As wardy07 points out, all that changes in a lens designed for a crop sensor camera is that it can be made smaller and cheaper because it doesn't need to produce the edges of the FF image circle that a crop sensor camera ignores.

Some very annoying people confuse focal length with angle of view. That causes lots of confusion. I wish they'd stop.

 

[odd jim]

It's the same.