A Question about Canon EF-S Lenses

[sherijohnson]

A thought came to mind last night and I started wondering, do the EF-S lenses provide a different range than EF lenses?

I started thinking since they are only made for certain models that maybe they were more true to what you would experience on a full frame camera but I had no idea how to find that out.

[ivar]

A thought came to mind last night and I started wondering, do the EF-S lenses provide a different range than EF lenses?

I started thinking since they are only made for certain models that maybe they were more true to what you would experience on a full frame camera but I had no idea how to find that out.The EF-S lenses are made to fit crop-sensor digital bodies. It produces a smaller image area (the sensor on the camera is smaller also), but the numbers of the 'range' have the same meaning.

If you were to take an EF-S 16-35 and an EF 16-35, they would have the same range on a crop-sensor camera.

[ziggy53]

"Crop" cameras are a different format from full-frame 35mm cameras. While many crop cameras have the same, or similar, lens mounts of their full-frame brethern, the Field-Of-View (FOV) per given focal length is different, hence the "crop factor" multiplier.

Canon cameras come in both crop 1.6x and 1.3x formats. The current Canon crop 1.6x camera bodies have a slightly different lens mount and they can allow mounting lenses of both EF and EF-S mount type.

EF-S lenses are unique in that they do not cover an image area larger than 15mm x 22.5mm, or so.

EF lenses are designed to cover an image area of 24mm x 36mm.

EF-S lenses also have a short back focus. (That's what the "S" in EF-S stands for.) Short back focus means that the rear element of the lens may protrude too far into the camera body to clear the mirror in a full-sized camera. The EF-S lenses will not attach to an EF body partly to prevent damage to either the rear of the lens or damage to the primary mirror of the camera.

BTW, the "crop factor" multiplier really is just a crutch to help people think about how a given lens's focal length "works" on the crop body. The effect is that a "normal/standard" focal length lens, on a full-frame camera, will act as a moderate telephoto lens on a crop camera body. The actual focal length never changes, only the effective FOV.

[sherijohnson]

Thank you for the clarification. You guys are great!