Apple finally pushed the iOS update bringing in the much-awaited Portrait Mode to the iPhone 7 Plus. This new Portrait mode was shown off at the Apple event as part of the iPhone 7 announcement in early September, however the company left the feature for release “later this year”. The feature leverages the dual cameras of the iPhone 7 Plus to generate images which have visibly shallower depth of field, excellent for Portraits. We have been testing the feature on our iPhone 7 Plus and here is the rundown on how effective the mode is so far.
Minimum Requirements, Maximum Output
The Portrait Mode on the iPhone 7 Plus works when the subject is within a limited range of the camera. If you get too close, the phone will ask you to step back and if your subject is too far, it will ask you to place the subject within 2.5 meters. What this means is that unless you are photographing a midget, it is unlikely you would be able to shoot a full-length portrait shot of your subject with shallow depth. Our model, who is about roughly four feet tall when seated barely managed to fit in the frame for Portrait mode to work.
Additionally, Portrait Mode requires more light to shoot the same scene in comparison to the 2x mode on the iPhone 7 Plus. When shooting indoors, our subject was lit by a standard LED tube light and while the normal camera (in 2x mode) was able to take the shot, the Portrait mode occasionally said there wasn’t enough light.
The Depth Map
Right off the bat, it is evident that the iPhone is using heavy algorithmic adjustments to generate the depth map in the image. When Portrait mode is enabled, you can see the out-of-focus areas move around as you move the phone to frame and re-frame your shot. In our test photos, we often found that the shallow depth even showed up around the edges of our main subject. There was even an instant where an object in the background wasn’t blurred out while everything around it was, creating a visually confusing image.
The over-process process
Shallow depth of field is a product of three things working in conjunction — focal length of the lens, size of the sensor and the aperture at which you shoot the image. Given a particular sensor size and aperture, the depth of field becomes shallower as the focal length increases.
The iPhone 7 Plus has a tiny sensor that automatically generates great depth of field. So, a long lens and a wide aperture are the only ‘true’ ways to get soft out of focus background. However, the iPhone’s sensor is too small for its 56mm lens and the f/1.8 aperture to give you the bokeh you need. This is where software comes in.
Apple’s algorithms are using the two cameras to generate a simulated shallow depth of field, but doesn’t manage to do so very effectively in most cases. Additionally, the images have significant amount of JPG compression, with details often getting too smudged. The Portrait mode also has a hard time resolving the colour white and there seems to be a consistent white balance shift as well.
Saved by the Beta
The Portrait mode on the iPhone 7 Plus is frankly a hit-or-miss feature, something that does not work with the efficiency that Apple products are known for. It could be that the feature will be tweaked further as Apple says it is currently in beta. The feature is decently implemented and matched by that found in the Honor 8.
The notion that “Apple products just work” does not apply to the Portrait mode on the iPhone 7 Plus as there are way too many hiccups to the mode as of now. But then this is a feature that has been a significant departure from Apple traditions as it was not part of a larger update and there was no particular release date in the first place.
Given that this is still in beta (good save Apple) we are hoping that Apple will continue to work on this. It would be nice to see the algorithm be able to tell the difference between foreground and background bokeh for one, which it fails to do at this point.