15mm

If you are even remotely serious about shooting video with a DSLR then you’ll quickly find that you need to add a few accessories.  For me a follow focus is the first thing I would pick up, as you’ll see in the following photos I use the excellent O’Connor F-Focus DM.  To attach a follow focus unit, and many other cine style accessories to your camera you are going to need a way to add rods.  In the cine world there are three rod standards: 15mm lightweight, 15mm studio and 19mm studio.  If you aren’t familiar with these then O’Connor