Photo Art from Science

If you buy Sigma’s USB dock to reprogram their lenses, it gives you the option to not only update their lens focus firmware, but also which focus algorithm(s) to choose. It’s almost like buying a new lens. If you have never programmed your Sigma lens using their dock, then your only focus choice is “Standard AF”. You get to choose among three different “AF Speed Settings” if you program their lens via the “Sigma Optimization Pro” program. The choices are “Fast AF Priority”,

Make a rugged and perfectly functional flash diffuser for free. Here's how to do it and why you want one of these.