For my 400D on a tripod. I understand about 'Mirror Lock-Up' and what it does. I am not sure what happens when using a cable release.
Do I first have to set up the focusing etc. using the half-pressed shutter button or is this all taken care of with the cable release?
Any tips on using a cable release would be greatly appreciated. Thanks.

Canon 30D, Sigma 50-500 EX DG HSM. Tamron SP 90mm F/2.8 Di Macro.
