All about Canon SLR part 2

EF lenses and EF-S

EF lenses (electrofocus) are artificial lenses that have Canon EF mount, so must be compatible with EOS cameras. EF lenses can be mounted on Canon EOS film SLR camera body (35mm) and in the body of any digital EOS, either with the sensor full frame, APS-H and APS-C. EF lenses now has many variants of both types of prime (fixed) or zoom. Even the luxury-class lens from Canon is also widely produced the lens with the code L-series (luxury), which is characterized by a red ring on the end. L series lens has excellent optical qualities and ability to hold thanks to the weather disturbance weathersealing therein.

In 2003 Canon launched the EOS 300D digital SLR (Digital Rebel) with kit lens EF-S 18-55mm. This is the first time introduced the EF-S lenses in Canon's history. EF-S lenses have a diameter image circle is smaller than EF lenses, designed specifically for DSLR with APS-C sensor so that the EF-S lenses can not be used for the EOS 35mm film camera. As for the lens EF and EF-S mount basically have the same shape and also contacts the same electronics, so EOS Digital cameras with APS-C sensor can be fitted with EF lenses (not EF-S lenses). But EF-S lenses are not properly mounted on the EOS Digital camera with a sensor larger than APS-C sensor because although it can be used but will produce a black circle on the edge of the image (vignetting) for EF-S lens diameter is smaller.

The letter 'S' on the code itself EF-S stands for Short (back focus), mean EF-S lenses have a much closer distance between the lens with the sensor.

Now available in the market and also a lot of EF lenses EF-S. If you plan to have a DSLR EOS with full frame sensor like the EOS 5D Mark II, then seek only EF lenses only. But if you feel quite satisfied with EOS DSLR APS-C sensor like the EOS 550D, EOS 60D or EOS 7D, the EF-S lenses can be an option.