Computational photography has long been a staple of smartphone photography, enabling tiny sensors to punch above their weight and perform some neat tricks, but is the technology at the point where it can replace traditional methods of photography?
One of the most intriguing uses for computational photography for me has been the ability to simulate long exposures. Olympus/OM System has long been a backer of this approach with its simulated ND filters built right into the camera, going so far as to add a computational photography button to its new OM-3. The iPhone has also long had this same feature, utilizing its Live Mode capture to simulate dragging the shutter by combining images from the short video frames it grabs around the still photo.
There are a lot of advantages to this approach, in that you don’t have to lug around heavy cameras and ND filters, but also in that you can activate the feature in almost any lighting or time of day—something that’s not necessarily possible with a mirrorless camera/ND filter combo without some preparation and planning. For instance, you may find that even a strong ND filter may not cut enough light to the sensor for the shutter speed you’re trying to achieve. On the other hand, the iPhone doesn’t give you a choice on shutter speed (and unfortunately doesn’t note the simulated shutter speed in its metadata).
iPhone vs. Low-End Camera
But enough about the intricacies of how it works. How does it actually look? For this photo, I pitted the latest and greatest iPhone, the 16 Pro, against a low-end mirrorless camera and so-so super-zoom lens, the Canon EOS R50 paired with a Canon RF-S 18-150mm f/3.5-6.3 IS STM lens (not the R5 used for illustrative purposes in the image above, though it, too, was shooting long exposures perched dangerously on those rocks). I used a high-end 10-stop B+W ND filter to drag the shutter on the Canon, mostly because that’s what I had, and I certainly could not afford to lose more image quality on the 18-150mm, which already makes some compromises to cram a large range into a small footprint. Spoiler alert: I’ll reveal which photo is which directly below, so don’t scroll too far down if you want to take a guess first. I’d also encourage you to look at this on a computer and enlarge the photo to see all of the details.
Both photos were framed and cropped as closely as possible, and both the phone and the camera were on a tripod so there would be no movement. Both photos were taken with each camera’s self-timer so no camera shake would be introduced with my hands, either. Finally, I edited the colors to be as close as possible, though in full disclosure there was not much flexibility in the iPhone’s files, as long exposures produce a JPG that doesn’t have the editing capabilities of a raw file from a mirrorless camera.
So which one is which? The photo on the left is the iPhone, with its computational photography producing the long exposure, while the photo on the right is the Canon mirrorless camera.
Viewed small on the phone, you’d be hard pressed to tell the difference. In the least scientific of polls, I publicly asked my photographer friends on Facebook to take a guess and explain their answers as to which one was which. Ultimately, most were able to figure it out if they looked at it on a big screen. As was pointed out by my network of photographers, when the photo is enlarged, you can see some choppiness in the water for the photo on the left, as if it’s mashing several frames together. In general, the rocks aren’t very sharp in the iPhone photo, and the iPhone photo applied a little HDR magic to retain the blue in the sky. Here’s a close-up crop of the photos where you can really see all of that in action:
While there is some wicked purple fringing from the Canon lens, there’s tons more detail and clarity in the image than the iPhone’s Frankensteined long exposure comes up with. The exposure on the Canon was ISO 100, f/8, and 10 seconds.
Does any of this matter? Maybe not if you’re just looking at things on a small phone screen, or if your audience is doing that. But if you care about quality at all, it looks like you may have several more years of carrying that bigger camera setup with you.