What is a cable release?

A SMDV Cable Release for Canon is an attachment, on a cord, that plugs into your camera. It allows you to trip the shutter mechanically without having to physically touch the camera – This reduces camera shake or operate the camera from a distance. A cable release is especially useful for long exposures with the camera mounted on a tripod. (like for night photography)
Camera manufacturers don’t allow cameras to take photos with exposures over 30 seconds w/o the cable release. So basically you’re forced to buy one if you’re going to do night photography.

cable release / Canyons night

They are fairly inexpensive, I just got one for $17. It was totally worth it because it has opened up a whole new world of nighttime photography to me. I’m pretty excited, here is my 1st shot.
Canyons Resort Utah / Night photography / May 24, 2014