APPLE iPHONE 8
So how good are the cameras in today’s smart phones? Over the next few issues tech expert Stephen Dawson puts a few of the models specifically promoted for their cameras through their paces. We’re only looking at the photographic capabilities of these pho
Regular Camera readers will know that we’re no great fans of camera phones, but there’s no escaping that they can be hugely convenient at times so, over the next few issues, tech expert Stephen Dawson is going to look at the smartphones that have the most capable camera capabilities. Not surprisingly, we’re kicking off with Apple’s latest iPhone model.
APPLE’S FILE PRACTICES REMAIN INSCRUTABLE TO ME...
it was Apple’s iPhone which introduced the half-decent phone camera to the world. The iPhone 3GS – or perhaps the five megapixels iPhone 4 – crossed a threshold from the half-decent to the actually quite useful. The current workhorse is the iPhone 8. The two higher level models, the iPhone 8 Plus and the iPhone X, add a second camera. We’ll return to one or the other in a future issue.
The iPhone 8’s rear camera is located in the top-right corner of the phone (when viewed from the front). The resolution is 12 megapixels, a sweet spot for phone cameras. The field-of-view is equivalent to the moderate wide-angle 28mm focal length in the 35mm format. The aperture is fixed – one of the many differences between a typical phone camera and a typical real camera. Bright scenes are handled by means of a faster shutter speed and a very slow ISO for the sensor (often as low as ISO 20).
The sensor is a backside illuminated (BSI) type which, in the topsy-turvy world of camera optics means that the image is captured by active sensors on the lens side of the wiring, rather than behind the wiring. That typically increases sensitivity by around half a stop. Optical image stabilisation helps reduce camera shake to ensure optimum sharpness.
Apple iPhones have at least one significant advantage over most Android phones in that they manage their batteries better so your phone camera is less likely to be depleted when you need it. What you don’t get in standard trim is the ability to capture RAW image files. The standard iPhone camera app instead captures the image in JPEG or HEIF. It’s odd that JPEG has remained the standard for lossy photo compression this past quarter century. The video and audio equivalents – things like MPEG2 and MP3 – have long since been supplanted by highefficiency compression regimes. HEIF apparently halves the storage space for the same quality, and also supports things like burst and stacked photos in a single file. The only problem is that there’s little external support for it yet. Even Photoshop CC won’t yet read HEIF files. So you’ll probably want to change the default to JPEG.
How? The camera app follows Apple’s practice of keeping some of its settings in the ‘Settings’ app. You have to scroll down a long way to find it. This is inconvenient for changing things like setting the video resolution or switching on the Auto HDR function. With the app you can choose the flash mode (On/Off/ Auto), switching the ‘Live Photo’ capture mode, the timer, and one of ten colour filters.
I don’t think there’s anything in the filters that can’t be done as well in post.
You can fire up the camera app without unlocking the phone by hitting the power button and swiping left. You can copy files to any computer by plugging it in via USB and opening the DCIM folder. Apple’s file practices remain inscrutable to me. Even with ‘High Efficiency’ chosen for photo selection, standard JPEG versions are the only things available in that folder. The HEIF versions synced to my computer via OneDrive. Even if I have ‘High Efficiency’ off, the same photos are uploaded via OneDrive with a completely different file name to that when imported via a wired connection. Oh, and you can’t see the file name of a photo on the iPhone itself, so you can’t take notes clearly identifying a shot.
The ‘Live Photo’ mode, incidentally, is actually a threesecond video clip, like the newspaper photos in a Harry Potter movie. The Panorama mode can stitch together multiple images to up to 63 megapixels in size, but it’s a bit limited, allowing a rotation of around 200 to 210 degrees. The stitching was adequate, but nowhere near the best out there, with visible bumps on some joins.
The first thing to note is that as a point-and-shoot camera under a wide range of circumstances, the iPhone 8 is glorious. It’s fast. Its focus is sure, and if you don’t like what it has chosen to focus on, you can select something different by tapping on the screen. That will also adjust the exposure based on that area. Swipe up or down to then adjust the exposure. Tap and hold, and you can fix both exposure and focus.
Don’t be misled by the fixed aperture of f1.8 and expect a shallow depth-of-field. The sensor is tiny and the angle-of-view fairly wide, so things are going to be in focus to great depth. Only extreme close-ups will give you a significant bokeh effect.
A digital camera depends on two things; its physical characteristics – sensor and optics -- and its signal processing. The latter is, in part, inherent to the phone and its OS and, in part, managed by the app. RAW photos not only avoid the compression artefacts of JPEG (or HEIF), but skip most of the image improvement features of the camera app. Apps tend to be based on the expectation that the photos will only be shown on the phone’s screen, so there is a tendency to over process the image.
With the test images I’ve paid close attention to not just all the standard stuff that even a cheap phone camera can do well, but also some extremes. I used the Halide camera app to capture RAW images for comparison.
The Apple iPhone 8 is a very safe choice for a phone camera. It does its stuff well. The standard app itself is a marvel of processing capabilities.
THE APERTURE IS FIXED – ONE OF THE MANY DIFFERENCES BETWEEN A TYPICAL PHONE CAMERA AND A TYPICAL REAL CAMERA.
But with Auto HDR the sunlit brickwork and tiles are resolved and the sky becomes blue, while the detail on the lattice is largely retained (ISO 20, 1/200 second, but those figures are meaningless since this is a composite of two photos created by the phone). The same shot with the iPhone camera app. It went for a longer exposure and delivered a semi-usable result (ISO 2000, 1/4 second).