Apple admits to a rare issue on the iPhone 17 camera. But as a camera expert, I think what’s happening is two different glitches – and one of them isn’t the camera’s fault

The new iPhone 17 series has just started shipping – but before the latest Apple smartphones even became officially available, one tech journalist spotted something curious: black boxes and darkened splotches occurring in a handful of shots taken at a concert.

CNN Underscored spotted the issue when writer Henry T Casey took both the iPhone Air and iPhone 17 Pro Max to a concert where, behind the musicians, the LED wall had dark splotches in some images and black boxes in others. (You can view the offending photos here.)

Apple has said the issue occurs only rarely and that it is already working on a software fix. But both the images of the glitch and Apple’s comment have me suspecting that there are actually two different errors happening in the series of photos – and one of them isn’t the camera’s fault.

The series of images show one image with black splotches appearing in the brightest parts of an image, which is a white squiggly design on a bright LED wall at a concert. Two photos show boxes of black over the LED screen, rather than irregularly shaped splotches.

The black splotches are likely an anti-blooming artifact

An Apple spokesperson said that the blacked-out portions happen when “an LED light display is extremely bright and shining directly into the camera.”

That phenomenon of an extremely bright light source wreaking havoc on a photo is what is happening in the image with irregularly shaped black splotches. I suspect what is actually happening in this case is an artifact created from anti-blooming.

When light hits a camera sensor that is too bright for the camera to record, it becomes a white spot in the image. This white typically bleeds into the neighboring pixels as well. CMOS sensors are far better at reducing this blooming effect than older sensors, but some cameras still try to reduce the intensity of blooming with software.

Blooming creates white spots, not black – but some cameras use anti-blooming algorithms to correct the issue with software. The newest iPhone 17 series uses more computational photography than any previous model and, while I can’t be sure, I suspect that’s what’s happening here with these irregularly shaped blotches.

When Apple said the iPhone 17 series has more computational photography than previous models, I felt more disappointed than excited – and glitches like this are one of the reasons why.

The good news is that the anti-blooming artifact is a software issue – and, as Apple says, a fix is already in the works.

Black boxes in the photos are likely a fault of LED technology, not the iPhone

But two of the images in the series don’t have irregularly shaped splotches, but entire boxes of black. I suspect what’s happening here isn’t a glitch in the camera at all, but a challenge in photographing any type of LED technology.

LED lights flicker, which happens too fast for the human eye to see. But when the camera freezes time during one of those flickers, LED lights appear to be off in the photo. This is an issue that I first ran into when trying to photograph a Christmas tree, and I embarked on a deep dive into why half my Christmas lights appeared to be off in some photos and not others.

LED flickering can also cause dark bands in an image. Electronic shutters – like the ones used on smartphones – expose one row of pixels at a time. Occasionally, you’ll wind up with a row of darker pixels because the LED lights briefly flickered as the camera was exposing that row of pixels. This is commonly referred to as banding.

But, the blacked-out portions on the sample product photos aren’t a dark vertical line of pixels, which is what banding looks like. So what’s happening? The key is that the photos where the glitch occurred were during a concert that used a large LED wall as a background.

LED walls are typically built up of smaller panels arranged together to make one large wall. The boxes in the images of the iPhone camera glitch suggest that the individual panel in that LED wall was in the off part of its flicker cycle when the photo was taken. This is supported by the estimate that those black boxes only appeared in about one in every ten photos.

Essentially, those black boxes are caused by the same thing that causes my Christmas tree to appear half-lit in some photos: a poorly timed flicker. That black box is probably just one LED panel in the LED wall that’s mid-flicker.

While this glitch is actually the inherent flickering of LED lights and not the camera’s fault, cameras can fix this issue. Some cameras have built-in anti-flickering modes that time the shutter to the frequency of the light flickers.

Another solution is to use a slower shutter speed as, when the shutter is open for a longer stretch of time, you reduce the odds that the picture will be taken during an LED flicker.

I can’t be 100% sure that anti-blooming and LED flickers are to blame for the iPhone 17 camera glitch – earlier iOS systems had black box issues too, and they had nothing to do with LEDs.

But based on the concert images, Apple’s comment, the location of the errors on an LED wall, and my frustrating journey with learning how to photograph Christmas lights, I suspect the issue is due to anti-blooming processing and the inherent difficulty that comes with photographing LEDs.

Neither issue requires new hardware to fix. I wouldn’t let the issue dissuade me from the new iPhone 17 – but maybe don’t use it to photograph a concert with an LED wall until Apple comes out with a software bug fix.

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