The Street Photographer's Guide to Autofocus
On my Sony A7RIII, no matter whether I am shooting street photography in the day or at night, I personally use Continuous Autofocus with a Wide focus area. Combined with Back Button Focus, I find that my hit rate is at 99%. The only focusing errors I have is when I am not still enough whilst holding the camera.
However, what works for me may not work for your process when you are shooting on the streets.
Let's take a look at the numerous different autofocus modes for street photographers, that you can try out today.
Note: Most of the modes discussed are written with reference to the modes on Sony cameras but I will also apply them to other brands.
Single Shot Autofocus
Single Shot Autofocus is probably the easiest mode to get to grips with. The camera simply focuses on a subject and doesn't continue to focus, once you acquire focus. It will lock onto a subject and stay locked providing you are half-pressing the shutter button or pressing the focus button if you are using back-button focus. This mode is best for stationary subjects, however, I have had great success using this mode for street photography on my Sony camera.
Canon
One-Shot AF - One-shot autofocus
Fuji
AF-S - Single AF mode
Leica
AFs
Nikon
AF-S - Single-area autofocus
Panasonic
AF S
Pentax
AF.S - Single Mode
Ricoh GR
Auto-area AF
Select AF
Pinpoint AF
Sony
AF-S - Single-Shot AF
Continuous Autofocus
If there is a moving subject in your shot then this mode is great for following and locking focus on the target. Once again, you will need to either keep the shutter half-pressed or keep your finger on the back button focus button for the camera to maintain tracking, whatever you or the subject is doing.
I use this for my street photography work. Continuous Autofocus, coupled with a Wide Focus Area, back button focus and a fast Shutter Speed, always delivers the sharp, in-focus results I am after with the Sony A7RIII. I have always found it reliable when shooting a street with groups of people in different areas of the frame.
Canon
AI Servo AF
Fuji
Continuous AF - AF-C
Leica
AFc
Nikon
Continuous-servo AF - AF-C
Panasonic
AF C
Pentax
AF.C - Continuous Mode
Ricoh GR
AF-C - Continuous AF
Tracking AF
Sony
AF-C - Continuous AF
Automatic Autofocus
This is a hybrid mode between Single Shot Autofocus and Continuous Autofocus. The camera switches between the two when the subject is moving and/or stationary. One can see how this might be beneficial for street snaps as people or animals in candid shots can be unpredictable. This mode is generally designed for beginners.
Canon
AI Focus AF
Leica
Intelligent AF
Nikon
AF A - Auto-area AF
Pentax
AF.S - Auto
Ricoh GR
Tracking AF
Select AF
Pinpoint AF
Sony
AF-A - Automatic AF
Autofocus Areas
When using Single Shot Autofocus and Continuous Autofocus you can fine-tune the focusing experience by using different Areas of autofocus that can make subject tracking even more refined, which gives you a greater level of control.
Let's take a look at the areas that are most useful for street photography.
Wide
Like I said I use this focus area almost exclusively. All the focus points are active and the camera picks a sufficient number in order to focus on the scene or subject. If I have a particular subject that I want to focus on, I will sometimes override this mode by touching the LCD to use a focus point on a subject.
Canon
Large Zone AF: Horizontal
Large Zone AF: Vertical
Fuji
Wide
Leica
Multi-Field
Nikon
Wide-area AF (L)
Panasonic
225 Area
Pentax
Auto (27 AF Points)
Ricoh GR
Auto Area AF
Tracking AF
Sony
Wide
Zone Area
This works similar to Wide except it functions as a smaller area in the centre, making it more focussed and less likely to pick up something at the edges of the frame. This could be great for street photography if a group of people are doing something in a specific portion of the frame as you can move the zone area around with the joystick. Some brands have different sized zone areas to choose from on certain camera models.
Canon
Zone AF
Fuji
Zone
Leica
Zone
Nikon
Wide-area AF (S)
Panasonic
Zone Square
Zone Oval
Zone Horizontal
Zone Vertical
Pentax
Zone Select
Sony
Zone Area
Flexible Spot Area
On Sony A7 cameras this focus point comes in multiple sizes and can be moved across the screen using the touch screen or with the wheel. It could be great for a stationary subject., like someone waiting for a train or a take-away.
Canon
1 Point AF
Spot AF
Fuji
Single Point
Leica
Spot
Field
Nikon
Single-point AF
Pinpoint AF
Panasonic
1 Area
Pinpoint
Pentax
Select
Spot
Ricoh GR
Pinpoint AF
Sony
Flexible Spot Area
Expand Flexible Spot Area
This uses points around the flexible spot for improved accuracy. The additional points can be used by the camera when the main point doesn't acquire focus. This may come in handy in areas of less contrast or low light, where the camera has more trouble focusing.
Canon
Expand AF Area
S Expand AF Area Around
Fuji
Single Point
Nikon
Dynamic Area AF
Panasonic
1 Area +
Pentax
Expanded Area AF (S)
Expanded Area AF (M)
Expanded Area AF (L)
Sony
Expand Flexible Spot Area
Lock-on AF / Tracking
This mode is great for focusing on running people, fast-moving subjects, and people on bikes or in cars. Once you press on focus the camera will lock onto the subject and track it no matter what position the subject moves to in the frame.
Canon
Face Detect - Eye Detect OFF
Expand AF area: Around
Spot AF combined with AO Servo mode.
Fuji
Wide /Tracking
Leica
Face/Body Detection
AF Tracking Start Position
Last Position
Recall
Center
Nikon
Dynamic-area AF
Pansonic
AFC AF Tracking
Pentax
Tracking
Ricoh
Tracking AF
Continuous AF
Sony
Lock-on AF / Tracking
Eye Autofocus
This mode is more of a custom function on Sony cameras than a standalone mode. It works specifically in Continuous Autofocus mode. Eye AF locks onto the subjects Eye and also tracks the eye as the subject moves and also can be used when shooting high frame rates. This would be great for street photographers who are shooting up close or are photographing street portrait photography. There is also an option for animal Eye AF. Great for wildlife.
Canon
Face + Tracking - Subject to Detect- Eye detection
Fuji
Face/Eye Detection AF
Eye Auto
Eye L R
Nikon
Auto-area AF
Panasonic
Eye Sensor AF
Pentax
Eye-detect AF
Ricoh
Auto Area AF
Select AF
Pinpoint AF
Continuous AF
Sony
Face/Eye AF Set
Back Button Focus
Back Button Focus is extremely useful for a number of reasons.
You can assign back button focus to a single, dedicated button, (usually the AF On button) rather than pressing the Shutter button halfway.
By doing this, if you are shooting stationary subjects, you can focus, let go of the button and recompose your image.
For moving subjects, you keep your finger on the AF-On button and you acquire focus before you fire the Shutter, thereby increasing your hit rate.
The camera is actively locking focus for as long as you are holding that button. Once you let go of the button the focus is locked and if your subject moves, just press the AF-On button again.
It's like using Single Shot Autofocus and Continuous Focus in one as there is no need to switch from one to the other.
Autofocus and Street Photography
AF S Wide / AF C Wide
As I said, I have been using Continuous Autofocus on Wide area for a long time. It is very reliable on Sony cameras. It may work well for your camera, try it out and see...
The scenarios that would work well with this focus mode and area are stationary subjects, slow-moving subjects like people shopping and browsing, and urban photography and night photography, such as buildings, street lights, shop windows, etc.
AF S / AF C Zone
Use this mode when your subjects are centred around the centre of the frame. A group gathered, people outside a shop or anything that enters the 'zone' area as you wait for the right moment to capture. You can also use Zone focusing effectively if you want to shoot someone who is in the background, behind someone. Note - You can move the zone around with the joystick if you want to.
AF S / AF C Flexible Spot
Use this focus mode when a single subject is stationary - standing around or waiting.
AF S / AF C Expand Flexible Spot
The additional focus points are beneficial. This mode is best used when there is a stationary subject that is in low light, a couple, or someone holding something, such as a pet.
AF C Lock-on AF
If you are the kind of street photographer that shoots moving subjects then this is the Autofocus mode and area are for you.
Imagine waiting for the right subject to walk past a beautiful, lit-up shopfront, or someone entering a shaft of light. Even a well dressed, or an unusual character strolling down the street. This is when Lock-on AF C works best.
Eye Autofocus
This mode is great for street portraits. Simply ask your subject to pose and use Eye autofocus to get that critical sharpness for the best results. Alternatively, if you are the kind of photographer who likes to get as close as you can when shooting candid street photography, then this function may work well for you.
Conclusion
Using Autofocus for street photography has become a lot better as camera brands have progressed in technology as the years have gone by. It's not completely foolproof, that's why many street photographers still use Zone Focusing with manual lenses much of the time. However, you can quite easily use the methods discussed in this article and get an excellent hit rate for your entire street photography career.
Go forth and create.