Getting the most out of Sony's autofocus technologies After years of development, Sony’s mirrorless interchangeable lens cameras offer among the most advanced autofocus technologies on the market, allowing photographers to create pictures that simply wouldn’t be possible with other systems.
Sony was among the first manufacturers to add phase-detection autofocus pixels onto a camera's main imaging sensor, which allows for ultra-precise focus. A wide spread of AF points and intelligent scene recognition algorithms are standard in Sony's market-leading a6000-series, a7-series and a9 cameras, allowing for powerful and accurate subject tracking. While these technologies are obviously useful for shooting fast-paced sports and action, features like face detection, Eye-AF and Direct Manual Focus (DMF) can also be employed for portraiture, landscape photography and video work.
In this article, we'll be outlining some key use-cases and recommending how to set up your Sony camera's autofocus system to get the best results.
Sports and action
Because, unlike a DSLR, there's no mirror in the way, the millions of pixels-worth of data from the image sensors in mirrorless cameras can be used to feed the cameras' autofocus and metering systems in real time. This allows for sophisticated object recognition and tracking. Autofocus data is also taken from the main imaging sensor itself, which means that AF is inherently more accurate than conventional DSLR systems.
The flagship sports-oriented Sony a9 for example features 693 phase detection autofocus points offering 93% coverage across the image area (illustrated above). Having so many AF points - and such a wide spread - makes it possible for the camera to accurately track action right out to the edges of the frame - something that isn't always possible with other full-frame cameras. Here are our recommended settings for shooting sports and action:
Recommended AF settings for sports and action:
Focus Mode: AF-C
Focus Area: Lock-on AF: Flexible Spot M
How to use: Frame your composition so the AF point is over your subject, then half-depress the shutter to start tracking it. At this point you can recompose the scene however you want, and your subject will continue to be tracked. To switch subjects, simply release the shutter, reframe to place the AF point over your new subject, and half-depress the shutter again.
Notes / Tips: This AF setup is also useful for more general photography: if you identify your subject by placing the AF point over it and engaging AF, the camera will keep track of it for you, making sure it's perfectly focused when you take your shot.
For some types of fast-action photography, like birds-in-flight, air shows, or any situation where your subject is the nearest object in the scene or well isolated against distant objects, you can often trust the camera to automatically identify the subject and focus on it. This avoids the need for you to reframe and place the AF point over your subject before initiating AF, saving you time and helping you capture the moment faster. To try this way of working, switch the camera's Focus Area to 'Wide', or use 'Recall Custom Hold'* to assign a custom button to this focus mode so you can instantly activate it in fast-paced situations.
*Only available on A9, a7R III and a7III Alpha cameras.
Portraits
For the serious portrait photographer, Eye AF is fantastic, letting you focus more on posing and expression and leaving the camera to do the rest. With Eye AF enabled, a Sony camera will continue to track your subject's eye, even when firing away at fast frame rates, which makes it a great option for catching just the right expression.
Sony's Eye AF system is very 'sticky' in that once it's been set to track a subject it rarely jumps off to someone else in the scene, even if your subject moves or momentarily turns away from the camera. And because of the wide AF area coverage, Eye AF will track your subject right out to the edges of the frame - this is useful for off-center compositions or erratic subjects like kids.
Recommended AF settings for portraits:
Focus Mode: AF-C
Focus Area: Flexible Spot M (or L)
Button Assignment: Assign Eye AF to AF-ON
How to use: If you have multiple people in the frame and are using any AF area other than 'Wide,' you can place that AF area over one of your subjects, and when you initiate Eye AF, it will track that person's eye. To switch subjects, release the Eye AF button, place your AF area over the other person, and re-initiate. If you simply want to focus on a person yourself, just place your AF point over the desired portion of your subject, and half-press the shutter to focus.
Notes / Tips: If you only have a single person in the scene, or you're happy to let the camera choose a face to focus on on its own (usually the nearest), switch Focus Area to 'Wide', then just press the Eye AF button.
Note that while we recommend assigning Eye AF to AF-ON for ease of use, you may wish to assign it to the AEL button if you prefer to use the AF-ON button for back-button focus.
Travel and general photography
As well as offering powerful autofocus features designed for portraiture and capturing fast-moving sports and action, Sony cameras are incredibly versatile when it comes to day-to-day photography. For general everyday and travel photography with Sony's mirrorless cameras , we recommend the following autofocus settings:
Recommended AF settings for general photography:
Focus Mode: AF-S
Focus Area: Wide (Face Priority in AF: On)
How to use: For general photography, we recommend you simply let the camera choose what to focus on. It will focus on faces in the scene, and prioritize nearer subjects over further ones.
Notes / Tips: If you wish to take control, just assign a button - like a central press of the AF joystick - to 'Recall Custom Hold'* and set its options to activate AF-S Focus Mode and Center Focus Area, with AF activation. That will allow you to quickly revert to the tried-and-true 'focus and recompose' method if necessary.
*Only available on A9, a7R III and a7III Alpha cameras.
Landscape photography
Traditionally, landscape photography has been the domain of manual focus, but even with static subjects, autofocus can be a huge time-saver. Here's how we recommend you set your Sony camera's AF for shooting landscapes.
Recommended AF settings for landscape photography:
Focus Mode: DMF
Focus Area: Flexible Spot: M (or L)
Button Assignment: Assign a custom button to focus magnifier
How to use: Compose your scene, then place the AF point over a portion of the scene you want focused. Use the focus magnifier to zoom into that region, then half-press the shutter to focus. While the shutter button remains half-pressed, you can turn the focus ring on the lens to fine-tune focus, then take your shot.
Notes / Tips: Using this technique, autofocus quickly gets you close to where you need to be, then it can be fine-tuned to achieve the correct balance of foreground and background sharpness for expansive scenes.
Video
Advanced HD and, more recently, 4K video features have been included in Sony's E-mount mirrorless cameras from the very beginning, and Sony's E-mount lenses are optimized for movie autofocus requirements as well as stills photography. Traditionally, a lot of filmmakers would rely on manual focus when shooting video, but Sony's mirrorless cameras' hybrid on-sensor autofocus systems function just as well (and in exactly the same way) when shooting stills and video, making AF useful and practical for videography.
Here are our recommended settings for video:
Recommended AF settings for video:
Focus Mode: AF-C
Focus Area: Wide (Face Priority in AF: On)
Center Lock-on AF: On
How to use: On their own, Sony cameras are capable of intelligently focusing in video, prioritizing faces and nearer objects, and smoothly racking focus when switching between subjects to focus on. If you turn 'Center Lock-on AF' on in the menus, you can choose which subject the camera should track (even if it moves around the frame) by simply tapping on it on the LCD. If your camera has a touch-sensitive screen, to switch to a different subject, you can just tap on it.
Notes / Tips: You can even customize how quickly the camera refocuses on your subject. In the menu, 'AF Track Sensitivity' tells the camera how responsive it should be subject movement, with the 'Responsive' setting best used for constantly and rapidly moving subjects. 'AF Drive Speed' controls how quickly the camera drives the lens focus element: 'Slow' yields the smoothest results, but 'Fast' is great for rapidly moving subjects and run-and-gun videography.
Note: Remember to turn Center Lock-on AF 'Off' before returning to stills shooting, or set up a separate Memory Bank for video shooting so its settings don't interfere with your stills settings.
This is sponsored content, presented by Sony. What does this mean?
. dpreview.com2018-12-3 17:36
