Pre-Release Capture Explained: Photographing the Past

A toucan peers out of its nest and seems ready to take flight at any moment. I wait eagerly in the hide, my finger on the shutter button, determined not to miss the moment when it flies out and spreads its wings. Cut to an hour later. I blink, I open my eyes, and the toucan leaves the cavity. My panicked brain processes what happened, then sends information through my spinal cord and a few peripheral neurons to my index finger, which finally presses the button. Damn, too late! But it didn’t have to be like this. Many of today’s cameras solve the problem of human reaction time with a feature known (among other names) as Pre-Release Capture. Let’s take a closer look at it today.

What Is Pre-Release Capture?

On some cameras today, when you hold down the shutter button halfway, the camera can continuously record a stream of images. But these images aren’t saved to the memory card unless you fully press the shutter button. When you do, all the images from the previous 1-second interval (or 1/2 second) are saved. This effectively lets you shoot “back in time” up to one second before you fully pressed the shutter button.

Pre-Release Capture is the name that Nikon calls this feature. Canon named it Pre (continuous) shooting. Fujifilm calls it Pre-shot ES; OM System calls it Pro Capture; Sony calls it Pre-Capture; Panasonic calls it Pre-Burst. No matter what they call it, the core idea is basically the same.

At a technical level, this feature works by continuously adding and then deleting images in the camera’s buffer. To me, the whole system resembles a water tank, with water (AKA new images) flowing in from one side and out the other while you hold the shutter button down halfway. Fully pressing the shutter button freezes everything, and you keep all the images stored from the previous interval in time.

Why Use Pre-Release Capture?

As I suggested in the introduction, this feature is most often used by wildlife or sports photographers. In general, anyone who photographs events that are very difficult to predict, and where one extra second of reaction time can make or break the photo.

I would venture to guess that more than ninety percent of the time, photographers use Pre-Release Capture when they are waiting patiently for a certain, very fast moment to occur. A kingfisher diving for prey from a branch, a chameleon shooting its tongue at an unsuspecting fly, a butterfly taking off from a flower, and thousands of similar scenarios.

The principle behind pre-release capture is basically the same for all cameras that have it. However, each one has some quirks. Let’s take a look at how each camera brand differs, and which current models offer Pre-Release Capture.

Nikon: Pre-Release Capture

Nikon implemented Pre-Release Capture on the Z9 in the camera’s first major firmware update in April 2022. This made them the first manufacturer to offer the feature on a full-frame camera. Until then, it was only available to users of some Olympus, Panasonic, and Fujifilm cameras. (Technically some of Nikon’s own Nikon 1 cameras had a related, but limited feature several years ago.)

• Buffer Length: 1 second, 0.5 seconds, or 0.3 seconds
• Supported Cameras: Nikon Z9, Z8, Z6 III, and Zf
• Burst Rate: Up to 120 FPS
• Limitations: Currently limited to JPEG Normal on all supported cameras. 120 FPS limited to 11 megapixels; 60 FPS limited to 19 megapixel with a DX crop; 30 FPS at full resolution. Nikon Zf limited to 30 FPS.
• Other Notes: Nikon also has a “post-release burst” to limit wasting space on the card, as well as a feature to group images taken in a burst to make it easier to delete excess images.

Canon: Pre (continuous) shooting

Canon was the second manufacturer after Nikon to introduce pre-release shooting to their full-frame cameras. It first appeared not on a top-of-the-line camera, but on a lower-end model – the Canon EOS R6 Mark II. It later found its way to two APS-C cameras, the R7 and R10, along with Canon’s higher-end bodies.

• Buffer Length: 0.5 seconds (or 20 photos on the EOS R5 Mark II and EOS R1)
• Supported Cameras: Canon EOS R1, EOS R5 II, EOS R6 II, EOS R7, EOS R10
• Burst Rate: Up to 40 FPS
• Limitations: On all cameras except the R1 and R5 II, the pre-burst images are saved as a single large file. From this file, the desired images must be extracted separately either in-camera or on a using Canon’s Digital Photo Professional software.
• Other Notes: On the EOS R5 Mark II and EOS R1, you can use a lower frame rate to extend the length of the buffer beyond 0.5 seconds (though I find 0.5 seconds is usually enough to compensate for reaction time)

Sony: Pre-Capture

Sony was the last of the Big Three to include Pre-Capture in its arsenal for full-frame cameras. So far, only the Sony a9 III has it. Like the Nikon Z8 and Z9, the a9 III is capable of continuous shooting at up to 120 frames per second. It can record a maximum of 1 second back in time, and it is capable of doing so with full resolution 24 megapixel RAW images.

The only possible limitation and bottleneck might be the buffer size in combination with the relatively slower CFexpress type A cards. A buffer with a capacity of 192 compressed RAW images and 96 RAW files with lossless compression requires careful timing of the shutter release when using the fastest burst. With lossless compressed RAWs, the buffer will theoretically fill even before you fully press the shutter. This can take you from the blazingly fast past to the painfully slow present.

• Buffer Length: 1 second
• Supported Cameras: Sony a9 III
• Burst Rate: Up to 120 FPS
• Limitations: Shooting at the full 120 FPS in RAW will fill the camera’s buffer very quickly (the camera’s buffer capacity is listed as 192 compressed RAW images or 96 uncompressed RAW). This will be worse with slower memory cards. So, you’ll have to time your images very carefully if shooting at 120 FPS. After 1 second of pre-capture, you will have less than a second of continuous shooting before the camera slows down.
• Other Notes: N/A

OM System: Pro Capture

The Pro Capture function is not new to OM System. Children born at the time it was introduced in December of 2016 with the Olympus E-M1 II can already read and write quite well. In the years since, Pro Capture has only grown and become more powerful.

• Buffer Length: Up to 1 second
• Supported Cameras: OM-1 Mark II, OM-1, E-M1X, OM-5, E-M5 III, E-M1 III, E-M1 II, and Tough TG-7
• Burst Rate: Up to 120 FPS (OM-1 Mark II only)
• Limitations: No autofocus at 120 FPS; drop to 50 FPS or less for autofocus. Other OM System cameras cannot reach 120 FPS in the first place.
• Other Notes: Instead of specifying the time, the Pro Capture setting specifies the number of frames to be captured – for example 50 frames. Like Nikon, OM System has an option to limit the number of frames per burst to save card space.

Panasonic: Pre-Burst

Panasonic wasn’t too far behind the pioneering Olympus with the launch of its Pre-Burst feature. The Panasonic G9 arrived with it in 2017. Since then, Panasonic has steadily improved things with a higher buffer capacity and up to 1.5 seconds of pre-burst.

• Buffer Length: 0.4 to 1.5 seconds
• Supported Cameras: G9 II, G9, S5 II, S5 II X
• Burst Rate: 20 FPS, 30 FPS, 60 FPS, 75 FPS
• Limitations: Manual focus only at 75 FPS (and not all supported cameras have the fastest frame rates; for example, the full-frame S5 II cameras max out at 30 FPS)
• Other Notes: On the supported M4/3 cameras, UHS-II SD cards are used and can take a long time to clear the buffer after a high-FPS burst

Fujifilm: Pre-Shot ES

Fujifilm is no newcomer to pre-release shooting. In 2018, it followed Olympus and Panasonic to implement this feature in the X-T3. Pre-Shot ES is available on a fairly wide range of Fuji cameras today.

• Buffer Length: 1 second
• Supported Cameras: X-H2, X-H2 S, X-T5, X-T4, X-T3, X-T50, X-S20, X-S10, X-T30 II, X-T30, X-E4, X-Pro3, X100V
• Burst Rate: Up to 40 FPS
• Limitations: On some of the older supported cameras, the electronic shutter had relatively high rolling shutter that could distort fast-moving subjects
• Other Notes: The only variable you can set is the number of frames per second, which can be selected from 10 FPS to 40 FPS (where available). Since the camera is set at the factory to hold one second in the buffer, the number of pre-recorded images is approximately equal to the frame rate.

Summary

One of the most important skills of a photographer is the ability to anticipate, to read the near future, and to react in time to an upcoming situation. For example, if a bird you’ve had in your viewfinder for a few minutes just pooped, chances are it’s going to fly away in the next moment. See a duck splashing water on the surface of a pond? It’s probably about to stretch out and flap its wings. Or do you see an athletically dressed young man running across the stadium with a long pole in his hands? There’s a good chance he’s about to jump off the ground and fly a good five meters high. However, when these simple rules aren’t enough, Pre-Release Capture comes in handy.

Perhaps you’ve just realized that you already own a camera with Pre-Release Capture, or maybe you’ve known about it for a while. Either way, I hope this article inspires you to try something new. Best of luck photographing the not-so-distant past! I’d love to hear about your experiences in the comments below the article.