DJI OM 4 review: New-name Osmo Mobile gimbal is one smooth operator

With smartphones getting better cameras with every generation, and so many now including both electronic stabilisation and optical image stabilisation, it's possible to get pretty smooth footage when shooting handheld. Still, to get completely other-worldly smooth footage, a powered gimbal offers a way to smoothness that you can't get from just holding your phone. 

One company that's been in the portable gimbal market for some time is DJI, and its success comes from having neat, portable devices that are packed with smart automated features, enabling you to capture things you could never do handheld without a lot of effort. For its fourth-generation - now branded as OM 4 and no longer Osmo Mobile - DJI has upped the ante, and even added a really versatile mounting system. 

Slick magnet

• Detachable magnetic attachment system
• Stick directly to your phone/case
• Min/max dimensions: 6.9-10mm
• Weight parameter: 230 ± 60g
   

Most of the OM 4's design has been seen before, in the Osmo Mobile 3, but the one thing that really stands out is the all-new magnetic system for gripping phones. Rather than having a permanently attached chunky grip for your phone that covers up buttons, or gets in the way of your hands, the latest has gone with a magnetic system. 

What this means is that you have two options for gripping your phone. Either you can use the really slim metal grip that holds onto the edges of your phone and snaps into place using a built-in strong magnet on the OM 4's arm, or you can stick a magnetic disc to the back of your phone. 

If you're the type of person who likes to use a ring grip on your phone anyway, this method makes a lot of sense. It has a ring that lifts up so you can loop your finger through it when you're holding your phone. Or you fold it down and then your phone snaps directly onto the OM 4. 

Those worrying about the magnet not being strong enough to hold a phone needn't fret. It's a pretty strong magnet. We tested it a number of times, and there was never any worry that the magnet wouldn't cope with our movements during shooting. Even with a relatively large phone like the iPhone 11. 

If there's a worry at all, it's that the magnet might be stronger than the adhesive grip that keeps the disc attached to the back of your phone. Pull it off too quickly and forcefully and you might find the disc stays attached to the OM 4 rather your smartphone. Thankfully, DJI supplies additional adhesive pads just in case you need to have another go at making it stick. 

While it's a cool approach to mounting a phone, there are obvious reasons not to use it. For instance, if you have a phone with wireless charging, it'll block your phone from charging on its stand. Which is where the standard grip comes in. 

It's a massive redesign for DJI to create this slim aluminium grip, which also uses that magnetic system to attach to the gimbal. The 'hands' that hold onto the edges are so small and slim that they don't get in the way at all. We found, when attached to a Samsung Galaxy S20, it made it a little tricky to get to the power button, but didn't completely block it. 

Still, it's a grip with extendable arms that will fit pretty much any smartphone, as it'll stretch to 84mm wide when fully extended. That's good enough to even fit in the behemoth Huawei Mate 20 X, so there are really no worries about your phone not being the right size.

Easy controls

• Physical zoom and panning controls
• Trigger for tracking 
• USB Type C port for charging
• USB-A output

Like the Osmo Mobile 3, the OM 4 has a decent selection of physical controls and buttons to reduce the number of times you need to touch your smartphone's display. 

The main panel beneath the actuating arm features a multi-directional pad for panning in any direction, plus the red record/shutter button and the power/mode button. To the left of that on the side of the handle you'll find a zoom slider switch for zooming in and out. 

Then there's the multi-purpose trigger on the front. Pressing-and-holding it locks the gimbal so that it'll keep the camera facing the same way, then letting go adds a little more flow to the movement.

Pressing once launches active track and automatically focuses on the subject; pressing twice recentres the gimbal; pressing three times switches between front and back cameras.

You can also use the trigger to launch sport mode - making movement faster and more responsive - by pressing once, then pressing and holding. 

For right-handed folks all the buttons are really comfortably positioned. You can reach the trigger easily with the index finger, and the zoom with your thumb. For using left-handed, it's mostly comfortable, but the zoom slider is a little less comfortable. 

Once you get the hang of what all the buttons do, it's pretty easy to use, but it's a slight learning curve to begin with. 

Shooting modes

• Motionlapse, Timelapse, Hyperlapse
• Panorama clone feature
• ActiveTrack 3.0

As with its drones, a lot of what makes DJI videographic products so attractive is all the work that goes on behind the scenes in terms of algorithms and programming. DJI drones wouldn't be nearly as popular without some of the automatic features that take care of all the hard things like pre-programmed flight patterns. 

It's a similar situation with the Osmo Mobile / OM series. Using the Mimo app, you can draw a square around a subject that you want to keep focus on and it'll cleverly lock onto that subject. Whether you move with the gimbal or the subject moves, it keeps a visual lock. For the most part this feature works well, but it can sometimes lose track if either you or the subject moves too quickly. or too close or far away from the camera. 

Then there are the special pre-programmed shooting modes. Switch into timelapse and you can adjust how long you want it to shoot for and the intervals between each shot. Or, you can take advantage of the motionlapse feature, adding in up to four different points to move across - which enables you to shoot some quite epic cinematic timelapses where the camera pans as it shoots the intervals. 

The one other feature on the video side that DJI's touting as a cool new feature is DynamicZoom. Think back to a horror or thriller movie you've seen where the subject, complete with shocked or horrified facial expression, remains still while the background seems to warp (either narrow or widen) behind them. It's achieved by the camera operator(s) moving the camera forwards or backwards while also zooming in or out to keep the subject equally filling the frame.

This is an effect that DJI has attempted to mimic with this dynamic zoom feature. Switch to the correct mode within the app, choose whether you want to move towards or away from your subject, then hit record and either move the camera forwards or backwards. In theory, it sounds simple, but in practice it's pretty difficult to get it looking good. Either we tended to move too quickly, too slowly, or at an inconsistent speed, so the result wasn't as smooth and gradual as we'd like. 

As for ActiveTrack 3.0, that's great when it works. You simply draw a square around the subject you want the camera to follow, or press the trigger one time with the subject in view. This then keeps the focus on that subject, whether it moves, or you move with the camera.

The only issue we found was that if the subject moved a little too fast, or we moved the camera too quickly, it soon lost track of the subject. We tested it on both the Samsung Galaxy S20 and iPhone 11 and the success rate for moving subjects - whether it was children or cats just walking around - was quite low. However, with slow movements around a still subject or a subject that moved quite slowly and stayed the same sort of distance from the camera, it was much more accurate. 

Then there's CloneMe, a neat panorama mode that allows you to place yourself in three separate locations within the same photo. You simple hit capture, make sure you're within the frame on screen before the five-second countdown stops, then move to the next spot, doing the same again for a third time. It's a pretty cool feature and - while maybe not one you'd use all the time - it's a lot of fun to try and come up with creative ways to clone yourself in the same picture. 

Of course, the mode most people will likely use the most is just using the regular follow mode - where you simply point your camera at a person/subject and follow them. The OM 4 really adds smoothness to images that you could never get from just holding your phone. If you have a phone that shoots 4K at 60fps then it can create some fantastic looking results.