Canon EOS (Electro-Optical System) is an autofocus single-lens reflex camera (SLR) camera series produced by Canon Inc.. Introduced in 1987 with the Canon EOS 650, all EOS cameras used 35 mm film until October 1996 when the EOS IX was released using the new and short-lived APS film. In 2000, the D30 was announced, as the first digital SLR designed and produced entirely by Canon. Since 2005, all newly announced EOS cameras have used digital image sensors rather than film. The EOS line is still in production as Canon’s current digital SLR (DSLR) range, and, with the 2012 introduction of the Canon EOS M, Canon’s mirrorless interchangeable-lens camera (MILC) system.
It’s a shame, because the M5 is so small and light that it should be a really inconspicuous camera. But it’s only modest until you press the shutter button, because after that there’s no mistaking that you’re taking pictures.
The name EOS was chosen for Eos, the Titan goddess of the dawn in Greek mythology, and is often pronounced as a word, although some spell out the letters, reading it as an initialism. It competes primarily with the Nikon F series and its successors, as well as autofocus SLR systems from Olympus Corporation, Pentax, Sony/Minolta, and Panasonic/Leica. In 2010, Canon held 44.5% market share in DSLRs.
At the heart of the system is the EF lens mount, which replaced the previous FD lens mount, which mainly supported only manual-focus lenses.
The flash system in the EOS cameras has gone through a number of evolutions since its first implementation. The basic EOS flash system was actually developed not for the first EOS camera, but rather for the last high-end FD-mount manual-focus camera, the T90, launched in 1986. This was the first Canon camera with through-the-lens (TTL) flash metering, although other brands had been metering that way for some time. It also introduced the A-TTL (Advanced TTL) system for better flash exposure in program mode, using infrared preflashes to gauge subject distance.
The M5 is not as fast as most photographers would expect their main camera to be, or as well built. At just under $1,000, this leaves the M5 in an awkward spot.
This system was carried over into the early EOS cameras wholesale. A-TTL largely fell out of favor, and was replaced by E-TTL (Evaluative TTL). This used a pre-flash for advanced metering, and used the autofocus system to judge where the main subject was for more accurate exposure. E-TTL II, which was an enhancement in the camera’s firmware only, replaced E-TTL from 2004.
Canon Speedlite-brand flashes have evolved alongside the cameras. They are capable of wired and wireless multi-flash setups, the latter using visible or infrared pulses to synchronise. Canon also produces Speedlite accessories, including the OC-E3 Off-Camera Shoe Cord, which can be used to hand-hold the flash while allowing the camera to control it through the cord. The Off-Camera Shoe Cord is popular among portrait photographers who need to have more control over lighting.