Another Newbie question. . .

[Rigby470]

Okay, since I am new to the dSLR world, there are a couple of things I need to know.

1. Is there a difference between digital lenses and lenses for film cameras? Are they interchangeable?

2. What does the "S" mean in EF-S?

I know, I know. . .but hey, I gotta start somewhere!

Keith

[Dante King]

Well, the difference in DSLR and SLR could be the mount. Old FD models will only work with an adapter and might not give you full camera control of the lens. Any EF lens will work on a DSLR but there is a crop factor of the lens depending on your sensor size. My 20D has a 1.6 crop. So mat makes may 28-300 lens actually a 44.8-480mm. So yes any ES mount is interchangable.

EF-S is canons new line made specifically for the Dreb and 20D. They bring the focal point closer to the sensor and are not interchangable for SLR or Full frame DSLRs or the 10D

Welcome to the best resource on the web for digital photography!

PS some of the other members could elaborate on my post.

[weemannie]

As I understand it, the focal length of the lens doesn't change, it the field of view that alters. So, with a lens of say 20mm the equivalent fov on a DSLR with the 1.6 factor is 20x1.6 i.e. 32mm. That is to say if you took the picture with a film camera, or a full frame DSLR such as the 1DS then cropping the image would give the same result.

[raylks]

Canon EF lens is compatible with all Canon EOS cameras including the film camera and digital camera.

The mentioned FD mount is the older generation mount for older Canon cameras which were discontinued around 1987 when the EOS was introduced.

Unlike FD, EF lens and EOS system enables automatic and quick and silent focusing. DSLR of Canon shares the same design structure of EOS film camera except the media where exposure is recorded.

EF-S was introduced along with 300D, and is compatible with 20D and 350D too. The structural difference from EF lens lineup is that EF-S is having a smaller imaging circle. Since 20D, 300D and 350D use CMOS sensors which are smaller than 35mm film, hence the "hole" where light pass through can be made smaller to reduce the cost of the lens accessories.

EF-S also feature a short back focus, which means that the rear element of the lens come closer to the CMOS sensor than as in film camera.