With more and more people using DSLRs to film rather than just snap photos, an increasing number are realising that the art of keeping shots in focus when moving around is really hard.

It's a problem the movie industry has suffered for years, with the simple solution in most cases being to have a dedicated "focus puller" to manage it for you.

That's not exactly practical for most of us, so in steps a new gadget that, while looking like a massive protractor added to your camera lens, should help you achieve focused shots without too much effort.

Called the FocusMaker, it's an "invaluable focusing tool for any DSLR filmmaker", according to its creators, who say it serves "both as a simple and easy to use follow focus system, as well as a device for making long travel rack focusing consistent, smooth and fast at very high accuracy".

The idea is that the FocusMaker fits on virtually any DLSR lens and provides an accurate overview of your focus points, while allowing a smooth operation with less fatigue and camera jitter.

The idea is incredibly simple. You set focus marks on the FocusMaker and then simply move the wheel around until you hit that mark and therefore your focus point. The additional long arm to hold allows greater control and - as you can see from the videos the company has made to show off the results - it works a treat.

The FocusMaker costs $89 and its makers say they will ship globally.