With this inexpensive add-on, Sigma offers lens owners a way to play the Wizard of Oz, allowing them to go behind the curtain to not only update the firmware of their lenses, but tailor them to specific shoots and preferences. The gadget pairs with Sigma’s Optimization Pro software, allowing you to choose different microfocus adjustment points. If, for example, a lens tends to back focus at a certain range, you can rewrite the firmware to correct it. With some Sigma zooms, you can adjust them to focus selectively in different focal zones.
Customization gets a little more interesting with the latest lens from their Global Vision line, the 120-300mm F2.8 DG OS HSM ($3,599). Through the software, you can change its autofocus to prioritize either speed (the motor will run quick and focus fast) or precision (the lens will take more time to focus smoothly). In addition, a focus limiter allows you to set a specific range and only focus inside of it. This would come in handy if you’re shooting a football game from a fixed point, for example. You could set up your lens to only focus on events in the end zone, enabling you to take more, speedier shots. And most importantly, if you’re tweaking the settings of an expensive new lens, you needn’t worry about permanently screwing it up. The software allows you to return it to default settings at the touch of a button.