The iPhone 5′s Low Light Boost Mode

Yesterday Daring Fireball’s John Gruber reported his findings that Apple’s built in Camera app on the iPhone 5 was capable of using ISO speeds up to 3200 – while 3rd party apps seemed to be limited to ISO 800.

This was troubling news, and I reached the same conclusion in my own testing.

However, after posting a thread (developer login ID required) to the Apple developer forums I’ve learned that 3rd party developers CAN take advantage of this special “low light boost mode”. (Thanks Apple!)

While it’s not documented yet in the AVCaptureDevice Class Reference, taking a peek at the “AVCaptureDevice.h” class header reveals the related properties:

lowLightBoostSupported
lowLightBoostEnabled
automaticallyEnablesLowLightBoostWhenAvailable

They chose to make the low light boost mode optional, as the increase in light sensitivity comes at the cost of some increased noise (not surprisingly). Making it optional was a good decision.

While this low light boost mode won’t make it into the update of Scout Camera that is currently “waiting for review” by Apple – I’ll be looking at implementing it for the next update.

UPDATE: I’ve added full control over the iPhone 5′s low light boost mode to Scout Camera. The following image shows the low light boost button in the upper right corner – which allows you to switch low light boost on/off. The button turns red when low light boost is active, so you can tell exactly when your photos will be above ISO 800.

(I had to turn a lamp off to get the low light boost to come on, which is why there’s not much difference in brightness between the “inactive” and “active” examples.)