We pull back the curtain on Sony AF.
Autofocus has become an integral part of production workflows due to its speed, reliability and precision. Sony is one of the leading companies in the development of autofocus technology that we can rely on in the field.
As resolution increases and higher frames per second become more common, autofocus algorithms can easily track subjects with superior precision. Sony uses a fast hybrid AF system that combines phase-detect AF and contrast-detect AF technology to deliver extremely sharp images, even in low-light conditions.
In the last decade, new technologies have emerged such as real-time face recognition, eye AF and animal AF. We spoke to Mark Weir, Senior Technology Manager at Sony, about the history of Sony autofocus and where it's going. This was what he had to say.
No film school: Sony autofocus is one of the best on the market. What makes it so reliable compared to others?
Mark Weir:Manufacturers like Sony, who design, engineer and manufacture the camera, image sensor and lenses, have a significant advantage in improving autofocus technology. But on top of the hardware there is also the algorithm. It's a combination of these things, the image sensor, the camera, the lenses and the algorithms that control them.
Cameras can only perform as well as the lenses can keep up. And the lenses, along with the camera, have a responsibility to follow the instructions and provide accurate information about the image sensor.
NFS: That makes good sense. If a company has interests in all three, cross-pollination and development can occur. Wonder if there was a turning point in the early days of AF development for mirrorless cameras?
overflow:Mirrorless technology or the way a mirrorless camera works and functions is a huge advantage that cameras faced in the past. Bringing the phase detection sensor into the image sensor was really one of the big breakthroughs from a hardware perspective. Without it, most of these benefits would not be possible.
When phase detection was first developed in SLR cameras, it was not done on the image sensor, but separately. This was one of the things that separated cameras from camcorders, and the separate sensor was prone to failure since the film plane and the focal plane were not the same.
Developing image sensor technology so that it could not only be done in the film plane, but developing devices that could work fast enough and process data fast enough to work on the image sensor fast enough was another step forward.
When the sensor takes a picture, it cannot measure phase correctly or vice versa if it needs to be able to measure the distance between the subject and the camera as many times per second as it does. It not only requires bandwidth from the image sensor, but also from the processor at incredible speeds. It's actually a combination of the device's technology and the algorithm needed to use the information to get everything done.
NFS: Phase detection is a big part of autofocus, but for Sony it's also contrast detection autofocus that makes Sony's fast hybrid AF. Was hybrid the first thought for Sony from the start?
overflow:In video recording, before phase detection was brought to the image sensor itself, you could only manage contrast detection. I'd say phase detection was realized around the same time, as was hybrid AF.
NFS: The combination is an absolute gem. Do you remember the moment Hybrid AF made its mark?
overflow:I remember when the Sony a7R II was introduced and it was truly a eureka moment when several journalists using the camera quickly realized something we hadn't even popularized: that the manufacturer's a7R II SLR lenses could focus faster through adapters than SLR cameras. .
I remember reading about it in the press and saying that if a Sony camera could do it, it would be a big step forward.
NFS: Lens adapters have really breathed new life into old lenses and allow us photographers to switch from one platform to another. But mirrorless lenses are made so differently than SLRs that it's hard to compare them.
overflow:It didn't take long for Sony to realize that lenses made for SLRs couldn't compete with lenses made for mirrorless cameras. Not only in terms of their optical formula and optical geometry, but SLR lenses do not take advantage of the short focal length of mirrorless cameras. But it was quickly discovered that lenses that were to really take advantage of mirrorless cameras would also have to develop new mechanisms to take advantage of the speed of mirrorless cameras.
NFS: Can you talk about how Sony's mirrorless lenses differ when it comes to autofocus?
overflow:When we started developing mirrorless lenses, we used rotary stepper motors to convert their motion into linear ones. That's about where other lens and system camera manufacturers are today.
But one of the things we discovered around 2014 was that we needed to rethink the way the autofocus trigger worked. Then we started making linear actuators that have no transition from rotary to linear motion - no gears and no friction.
Even today, the latest lenses introduced by mirrorless camera manufacturers or third-party lens manufacturers use rotary actuators. The spiral mechanism or gears required to convert rotary motion to linear motion slows it down significantly and can cause errors and noise.
We switched to linear actuators 4-5 years ago.
NFS: That tells us a lot about why Sony mirrorless lenses are so good.
overflow:It is not only precision, but also speed. We used to live in 24p, but now we live in a world of 4k 120p in mainstream cameras. You don't need to spend $50,000 to get 4K 120p slow motion. If you can't focus tens of thousands of times per second, you can't use autofocus with wide aperture lenses on high frame rate cameras.
OfFX6IFX3cameras are capable of capturing shallow depth of field with wide-aperture lenses thanks to their full-frame image sensors and can provide the necessary autofocus. Focusing at 120p is quite a challenge when depth of field is measured in fractions of an inch.
It is part of the revolution. Autofocus systems are adept enough in these challenging situations that they are starting to take over. Especially in the world of solo shooters.
NFS: I totally agree with you. I'm glad you mentioned the FX series. ThatFX9,FX6, dvsFX3they all share the same hybrid autofocus technology as the Alpha series, right?
overflow:It is a common technology and it is in the same direction. We believe that hybrid AF, which combines the speed and ability to track and recognize objects with phase detection autofocus, will become an increasingly important component.
Contrast AF is great for accuracy, but inherently challenging for speed. It is depth finding, but it is not aware of depth. And the very nature of depth awareness gives phase detection an advantage when you need to know which direction to go. Something that contrast detection practically cannot do.
NFS: Can you talk about how Eye AF and Animal AF have evolved?
overflow:I understand how it is implemented that eye recognition is an extension of face recognition.
Facial recognition was demonstrated at Photokina 2009. It searches for certain facial features and recently, as technology has developed, facial recognition has been advanced using artificial intelligence to not only detect facial features but also refer to a database image and its use would improve the efficiency of recognizing their objects and subjects.
I think the idea of eye tracking is the next step in that process. I think as we implement it in a variety of devices, facial recognition and eye recognition will be supplemented with other information such as color, depth, motion, etc.
When we see an eye tracking system go into animal or bird AF, we see a little variation in the way the algorithm works, and probably a little variation in the database that the intelligence points to when tracking.
NFS: Can you talk about what's next for Sony autofocus?
overflow:I'm really not involved in the development cycle. However, I think most of the development is focused on meeting end-user requirements.
And if we look at end-user requirements, it would be things like better performance, more positive identification, more efficient tracking, and the ability to regulate tracking persistence. Or it ignores or reacts to other elements or objects entering the camera and the subject being tracked. They are probably all high on the list. And we are already doing that. We already have the option for users to adjust the tracking sensitivity usingFX9, FX6 and FX3.
FAQs
Why is Sony autofocus the best? ›
The autofocus system covers 92% of the image with a combination of 759 phase-detection points and 425 contrast-detection areas. The Sony a1's AF system works for both photo and video applications. The AF system is built to automatically focus and track eyes whether your subject is human or animal.
What does hybrid autofocus mean? ›Hybrid Autofocus
On the sensor, you have lenses which is the Phase Detection part, giving it the ability to focus really quickly on your subject. Then it switches to Contrast Detection to get that nice, crisp quality. The best parts of each system work together to give you a fast and precise AF.
Fast Hybrid AF is an auto focus system that combines the traditional Contrast detection AF with Phase detection AF. Combining both of these auto focus features is great for added precision and ideal for a quick response when tracking fast-moving subjects.
Which Sony camera has the fastest autofocus? ›Sony's a6100 and a6400 are among the fastest focusing cameras available. Sony claims to be able to focus in 0.02 seconds.
Why Sony cameras are better? ›Sony vs Canon: Image Sensors
Many other Camera brands have a Sony sensor inside their Camera body. Even the iPhone Camera uses it. It is a given that Sony will have better sensors. With these sensors, you can have pictures of great quality even in low light.
Sony cameras, and especially their APS-C lineup, are generally a little more compact than alternatives from other brands. Excellent image quality. Sony cameras generally take sharp images that are low in noise, even at moderately high ISO levels. Lens availability.
What is the advantage of autofocus camera? ›Autofocus is generally faster and easier than setting the focus manually. It can lock onto a subject faster, as well. This makes it suitable for shooting moving subjects. If you're doing street photography, for example, you could only have seconds to capture your subjects.
What type of autofocus is best? ›Continuous autofocus mode (AF-C / AI Servo)
Continuous autofocus (AF continuous) modes are the best AF modes for moving subjects. Once you've set your focus, your camera will continue to track the subject, even if they move around within the frame.
A digital camera that accepts different lenses but does not use a mirror to reflect the image into the viewfinder. Also called a "mirrorless interchangeable-lens camera" (MILC), "hybrid camera" and "compact system camera" (CSC), the body is thinner than a digital SLR (DSLR) because there is no mechanical mirror.
How do I use Sony autofocus? ›Autofocus operates when the shutter button is pressed halfway down. Once the subject is in focus, the focus is locked. It is suitable for shooting motionless subjects such as landscapes or snapshots.
Which Sony cameras do focus stacking? ›
One of my favorite features introduced with the Sony a7R V [ Amazon | B&H Photo ] is the ability to capture focus brackets in-camera, which you can stack during post-processing to create sharp photos along a greater depth.
What is Sony eye autofocus? ›Focuses on a person's eyes when you press the button. MENU → (Custom Settings) → [Custom Key Settings] → assign the [Eye AF] function to the desired key. Press the key to which you have assigned the [Eye AF] function and focus on the eyes. Press the shutter button while pressing the key.
Why do mirrorless cameras have better autofocus? ›You'll know if your photo is over or underexposed before you take the shot. The auto focus is better because mirrorless cameras use the sensor to focus, while a DSLR has a second sensor for focusing and there can be calibration issues that lead to slower focusing and more out-of-focus photos.
Do Sony cameras have auto focus? ›During continuous shooting, the product automatically shoots with Continuous AF from the second shot. (Continuous AF): The product continues to focus while the shutter button is pressed and held halfway down.
Which mirrorless camera has the fastest autofocus? ›What mirrorless camera has the fastest autofocus? The Sony a6100 and a6400 are among the fastest focusing cameras on the market.
Do professionals use Sony cameras? ›Nikon is the most popular camera brand used by professional photographers. 31% of professionals use Nikon, closely followed by Canon (28%) and Sony (20%).
Why are Sony sensors so good? ›Sony pioneered stacked sensors that put fast memory and other electronics directly under the sensor, allowing for faster readout speeds and thus rapid burst shooting and reduced rolling shutter (jello effect) on cameras and smartphones.
Is Sony a professional camera? ›Sony's range of the world's most popular professional camcorders enables total creative, operational and economic flexibility.
What are the pros and cons of cameras? ›- Pro: Increase Public Safety. ...
- Pro: Reduce Crime Rate. ...
- Pro: Helps Catch Criminals. ...
- Pro: Provide Evidence & Gather Clues. ...
- Pro: Convenience. ...
- Con: Easily Abused. ...
- Con: Doubts About Effectiveness. ...
- Con: Expensive.
Innovation is key to sustaining success. Sony faced fierce competition from other established companies as well as foreign policies. However, its main ingredient of success remained its powers of innovation – from the VCR to VHS and the mighty Walkman.
What are three advantages of digital cameras? ›
| Digital Cameras | |
|---|---|
| Television | Images can be viewed on a large-screen TV. |
| PC | Image data can be immediately used on a PC, without processing. |
| Retouching | Editing and processing are easy, using photo editing software. |
| Cost | No film purchase or development costs, Rechargeable battery packs are economical. |
1.4. 2 Autofocus. Autofocus or AF is the autofocus function that accompanies most cameras today. This device can automatically adjust the sharpness of the subject, which ensures successful and sharp images in 90% of the cases.
How accurate is autofocus? ›Autofocus accuracy within 1/3 of the depth of field (DOF) at the widest aperture of the lens is common in professional AF SLR cameras.
What is the difference between focus and autofocus? ›While autofocus automatically adjusts itself to achieve focus, manual focus lets you decide for yourself what's in focus, and how sharp it should be. Autofocus does the work to nail focus and make sure your shot is sharp. Meanwhile, with manual focus, you rely on your eye to tell you the image is sharp.
Which is a disadvantage of autofocus? ›Cons of Autofocus Lenses
They may fail in low-light situations since defining features are difficult for autofocus lenses to distinguish. Additionally, if a scene is busy or you are trying to focus on something far away, autofocus may not allow you to pinpoint what you want.
Fixed-Focus is best for handling high-vibration environments. Auto-Focus uses an electromagnet to move a magnet that is mounted to a free-moving lens. In high-vibrations this electromagnetic force is overpowered and the lens vibrates all over the place, causing blurry/weird/”jello” images/video.
How many types of autofocus are there? ›There are two types of AF (Autofocus) systems – Active and Passive. The “Active AF” system works by shooting a red beam on your subject, then bouncing that light back to your camera to figure out the distance between the camera and the subject.
Why are hybrid models better? ›Hybrid cars are typically more fuel-efficient than their gas counterparts since they can switch between their gas and electric motors while being driven. The key reasons to consider buying a hybrid car are to save on gas and help reduce emissions while still getting the range capabilities of a gas car.
What is the meaning of hybrid camera in Sony? ›Hybrid image stabilization (HIS), as the name suggests, means that the camera combines optical image stabilization (OIS) and electronic image stabilization (EIS) simultaneously. With Hybrid image stabilization, you can take less blurry videos even in challenging conditions.
What are the disadvantages of hybrid lenses? ›Speaking of hybrid contacts, many people find that even though hybrid lenses can provide sharper vision, it might be more challenging to find a comfortable fit. Hybrid lenses also may not be a great choice if you struggle with lenticular astigmatism.
Why is my Sony autofocus not working? ›
Turn off the camera and leave it in a dry place away from direct sunlight. Then, wait about an hour for the moisture to evaporate, and check if the issue is resolved. If the focus mode is set to manual, switch it to the auto mode. Then, check if the camera will focus.
What is Sony focus standard? ›If you press the key to which [Focus Standard] is assigned, you can recall useful functions such as automatically focusing on a subject in the center of the screen in accordance with the focus area settings.
What are the two types of camera focus? ›Most photographers use two types of focusing, manual focusing in which the photographer focuses on the subject by turning the focusing ring on the lens and autofocusing (AF), where the camera focuses on the subject.
What is Sony focus Hold? ›Locks the focus while the key to which the Focus Hold function has been assigned is pressed. MENU→ (Camera Settings2)→[ Custom Key] or [ Custom Key] →assign the [Focus Hold] function to the key of your choice.
Is autofocus a lens or body? ›In simple terms, autofocus applies to a mini computer in your camera that automatically focuses your camera lens to achieve the sharpest possible image. Although controlled by the camera, most cameras today have autofocus motors in the lens as opposed to the camera body.
How does autofocus work in the eye? ›What Is Eye-Start AF? Eye-Start AF is a feature that allows the camera to start auto focusing on your subject as soon as you put your eye on the viewfinder. Note: Eye-Start AF is only available when an A-Mount lens and A-Mount adapter, such as LA-EA2 and LA-EA4, are attached.
How do autofocus lenses work? ›Autofocus is an algorithm or system that takes the pressure off when you want a perfectly focused photo. With this software, your camera does all the work to figure out how to focus on the subject in your frame. The lens scans the scene and automatically identifies the subject on which to focus.
Do photographers prefer mirrorless cameras? ›For beginning photographers, the ability to see your exposure while composing your shot is a significant advantage of mirrorless cameras. You'll see in real-time how your settings change your exposure, and depth of field. In some models, you will even see the live histogram to ensure proper exposure.
Why do people prefer DSLR over mirrorless? ›The DSLR offers a wider selection of interchangeable lenses, longer battery life, and better low-light shooting thanks to the optical viewfinder. On the other hand, mirrorless cameras are lighter, more portable, offer better video quality even in lower-end models, and can shoot more images at faster shutter speeds.
What is the biggest advantage of mirrorless camera? ›In summary, mirrorless cameras offer several advantages over SLRs, including their smaller size, faster shooting speed, and better video capabilities. However, they also have some disadvantages, such as shorter battery life, limited lens selection, and higher price points.
What is Sony real-time eye AF? ›
Eye AF uses Sony's remarkable wide AF area and accurate eye detection to open up unimagined freedom of composition, so you can explore creative expression like never before. A subject's eyes can be detected as soon as the shutter button is half pressed, then tracked continuously in AF-C mode with outstanding accuracy.
Which Sony cameras have real-time eye AF? ›Sony's acclaimed a7 III and a7R III mirrorless cameras have received an exciting firmware update—Software Version 3.0— that enhances Real-time Eye AF performance and adds Real-time Animal Eye AF and interval shooting for time lapse.
Which Sony camera has real-time eye AF? ›| Sony A7 IV | Sony ZV-E10 |
|---|---|
| Sony Alpha 1 | Sony A7C |
| Sony A6600 | Sony A6100 |
| Sony A9 | Sony A7R IV A |
| Sony A7R III A | Sony A7 III |
Mar 07, 2023: Replaced the Sony α7 IV with the Canon EOS R6 Mark II as the 'Best Mirrorless Camera'.
Do mirrorless cameras have faster autofocus? ›Mirrorless cameras have faster and more accurate autofocus than DSLR cameras, making them better for action photography. All but a few mirrorless cameras now have both phase and contrast-detection sensors built into the image sensor. Best cameras over $2500 in 2022.
How does mirrorless autofocus work? ›With mirrorless cameras, no special chip is needed, and the main sensor handles “looking” in different directions. Each of the pixels is split in half, so it can distinguish light from the left and right. Mirrorless cameras focus directly onto the main sensor using pixels that are split in half.
What is the best autofocus method? ›Continuous autofocus mode (AF-C / AI Servo)
Continuous autofocus (AF continuous) modes are the best AF modes for moving subjects. Once you've set your focus, your camera will continue to track the subject, even if they move around within the frame.
Nikon is the most popular camera brand used by professional photographers. 31% of professionals use Nikon, closely followed by Canon (28%) and Sony (20%).
Do pros use auto focus? ›Manual focusing gives photographers the ability to have the most control over the images they create, which is why the majority of professional photographers do not use autofocus systems. Yes. Many professional portrait and landscape photographers use aperture priority.
How do you improve autofocus accuracy? ›- Know when to – and when not to – focus and recompose. ...
- Use particularly wide apertures cautiously. ...
- Fine-tune your AF. ...
- Dig out your manual. ...
- Use your customisable buttons. ...
- Limit your focusing points.
What is autofocus good for? ›
Autofocus: Pros
This allows you to set your focus point on a subject, then track it through the frame. As you can imagine, AF tracking is great for shooting moving subjects such as birds in flight, wildlife on the run, and sports players in action.
Sony makes the best sensors in the world. These sensors are being utilized by almost every field that relies on… image sensors. Sony's image sensors are designed for various applications: Automotive, industrial, medical, and cinema.
Which Sony sensor is best? ›A: The Sony IMX989 is a highly advanced image sensor that utilizes photodiodes and semiconductor devices to convert light into electrical signals. It boasts a 50.3 MP resolution and has 50 million photodiodes arranged in a grid pattern, each capturing light from a specific point in the image.
Who uses Sony sensors? ›In addition to the image, Cook reveals that Apple has been using Sony Semiconductor image sensors 'for over a decade to create the world's leading camera sensors for iPhone.
Which is the No 1 camera in the world? ›The Canon brand is the current leader in the camera space, though Canon is most known for its high-quality DSLRs and DSLR lens lineup.
Is Sony better than Nikon for image quality? ›Sony is better at most things: autofocus, low light performance, native lens range, 3rd party lens support, dual card slots, exposure compensation dial, video, customisation, and battery life. Nikon is better at some things: grip and handling, menu layout, monitor resolution, and touch screen.
Is manual focus sharper than autofocus? ›While autofocus automatically adjusts itself to achieve focus, manual focus lets you decide for yourself what's in focus, and how sharp it should be. Autofocus does the work to nail focus and make sure your shot is sharp. Meanwhile, with manual focus, you rely on your eye to tell you the image is sharp.
What is the drawback of auto focus? ›Works in Low Light
An auto focus lens may not be reliable in low-light settings. Therefore, a manual focus lens is needed to capture a suitable photo.
Fixed-Focus is best for handling high-vibration environments. Auto-Focus uses an electromagnet to move a magnet that is mounted to a free-moving lens. In high-vibrations this electromagnetic force is overpowered and the lens vibrates all over the place, causing blurry/weird/”jello” images/video.