How to delay the shooting of canon SLR

automatic time-lapse photography can use the lowest ISO(1 or lower), with an aperture of F16 or smaller, (if it is daytime, an ND reduction lens is required,)

In this way, the camera will automatically take a long exposure in A file.

you can set your own shutter in the M range. The slowest automatic shutter is generally 3S. If you continue to dial, it will turn to the buld door, that is, the B door. You can freely control the exposure time under the B door, and you can expose it as long as you press the shutter.