Have you ever been photographing trackside, and then all of a sudden, something major plays out in front of you, so you hold the shutter button down in hopes of getting as many shots as possible, only to hear your camera slow down and struggle to take photos? You, my friend, have hit your cameras buffer.

It’s the worst feeling, sitting there waiting for your camera to clear the buffer while something, usually a significant crash, plays out in front of you.

The first time it happens, you might think there is something wrong with your camera. But after you’ve experienced it a few times, you start to understand what it is and when it is most likely to happen.

What Is Camera Buffering

Camera buffering is when you hit the limit of the temporary storage capacity (buffer) of your camera by taking multiple images in rapid succession. This can happen more frequently when you capture photos in burst mode or continuous shooting mode.

Your digital camera doesn’t write photos directly to your memory cards. Instead, it writes the image to a temporary internal storage, known as the buffer and then transfers that image to your memory card to make room for the next photo you capture. As a result, when you take multiple photos in quick succession, the images fill up the camera’s buffer faster than they can be written to the memory card.

With that in mind, buffering happens because the camera’s image processor is recording images faster than the write speed of the memory card allows it to receive the data and clear the images out of the buffer. While the buffer can hold a small number of files while they are being written to the memory card (the number of images and the size of the buffer varies from camera to camera), once the buffer becomes full, the camera slows down or stops taking new shots until it can transfer the images from the buffer to the memory card.

What Causes Buffering And How To Fix It

Now that we’ve discussed the fundamentals of what buffering is, what causes it? Well, there are actually a number of factors that could cause you to experience buffering with your camera.

Large File Sizes

It goes without saying that the larger the file size of the photos you are capturing, the faster the buffer is going to fill up.

If you are capturing photos in your camera’s full, uncompressed RAW format, the file size is going to be significantly larger than shooting in the compressed JPEG format. And as a result, it’s going to take fewer photos in quick succession for your camera’s buffer to fill up if you are shooting in the RAW format and longer for those files to write to your memory card.

In addition, the bigger your camera’s sensor (the more megapixels it can capture), the larger the files are going to be, both in RAW and JPEG. Keep this in mind you are photographing a motorsport event with two different cameras. One might be more inclined to hit the buffer during those high-action moments than the other.

Slow Memory Card Write Speed

The speed at which the camera can transfer the images from the buffer to the memory card depends ultimately on the write speed of the memory card. The slower the write speed of your memory card, the more likely it will become the bottleneck, causing buffering delays regardless of how modern and fast your camera is.

This can present itself if you buy a newer camera (especially with a larger file size) but continue to use your older memory cards that you’ve had for several years. Something that is more common when using SD Cards as while the card format has remained the same, the technology within them has continued to improve, leading to faster and faster write speeds.

Just keep in mind that different memory card technologies have different write speeds. This is particularly important to note if you are using a camera with dual card slots.

Most current mirrorless bodies from Canon, Nikon and Sony (at least from the middle to the top of their range) will offer dual card slots. Typically one is for a CF Express (XQD) Card, and the other is for an SD Card. And while there are many benefits to recording photos on both cards, the SD Card is always going to be significantly slower (even the latest generation of highspeed (SDHC) high capacity (SDXC) cards) than the CF Express (XQD) Card. It’s just the difference between the two technologies.

I’ll put together a post shortly about the different memory card technologies as well as recording images to two cards at the same time and how they can affect your motorsport photography.

Memory Card Formatting And Maintenance

Have you noticed that your camera is buffering more often than it used to? That might be associated with how you format and maintain your memory cards.

If you move and/or delete your photos off your memory cards without formatting the cards, little trivial artifacts of data remain on the cards. While this may seem insignificant, when your camera writes the next photo to the card, it needs to record the image in and around these small remnants of data. Slowing down the process of writing the image to the memory card, regardless of how fast it is.

The best thing you can do to not only ensure the best performance out of your memory cards but also extend their lifespan is to format the cards within your camera once you’ve downloaded the photos to your computer (and made sure you’ve got sufficient backups).

While your could format your memory cards in your computer, that has a tendency to introduce other data artifacts. So I recommend sticking with formatting the memory cards within the camera itself.

Also, make sure that you avoid getting dust and dirt in or on the pins of the memory cards. When this ends up in card slots, this can reduce the contact between the camera and the card leading the data read/write issues. This could present in slow write performance and buffering but could also lead to data corruption and losing your photos.

While less of an issue with modern cards, with older CF (Compact Flash) cards, you also have to be mindful not to bend the pins in either the camera or the card reader, which could also cause similar issues.

Slow Camera Bus Speed

Occasionally there can be an anomaly in the way camera manufacturers design and build their cameras where the bus speed isn’t sufficient enough to allow images to transfer at the full write speed of the memory card.

One example that comes to mind is the Canon 5D Mark 3. When writing to the CF (Compact Flash) card, the camera would operate at its optimal performance. But if you used an SD Card, no matter how fast it was, you would most certainly hit the buffer because of a limitation in the bus speed of the SD Card slot.

You could get around this by not using an SD Card slot, but it did take away the benefits of using a camera with dual card slots, like always having two copies of your photos.

Camera manufacturers do their best to future-proof their camera bodies, but they are limited to the technology available at the time. So if you have an issue where you hit the buffer regularly on an older camera (particularly DSLRs), buying the latest and fastest memory card may not be the instant fix you are looking for.

Burst Shooting

Shooting in burst mode or high-speed continuous mode is something we do a lot of in motorsport due to the highspeed action-packed nature of the sport, but it is also this capturing of rapid series of images in quick succession that is most likely to cause your camera to hit the limit of the buffer regardless of how good your camera is or how fast your memory cards are.

Higher-end cameras like the Canon R3, Nikon Z9 etc, are built with this in mind and feature larger buffers to give you more time before hitting its limitation, but regardless of the camera, if you sit on the shutter button too long enough, you will find the limit.

I typically leave my cameras in burst mode or high-speed continuous mode so that if something unexpected happens, I can capture it, at least until I hit the buffer. But I’m also mindful to only hold the shutter button down briefly to ensure that I don’t capture too many photos at any one time so that the buffer is as empty as possible just in case something unexpected does happen.

Overheating

Did you know temperature can impact the performance of your camera? While more common when recording long segments of 4K (and 8K) video footage, large continuous bursts of large photo files (RAW files) can cause your camera and memory cards to heat up – particularly when using CF Express cards.

You might have already noticed this temperature either while holding your camera while taking a lot of photos in quick succession. But when using CF Express cards, you’ll also notice it after you’ve downloaded photos onto your computer. The card can and will get significantly hot both when writing and reading large amounts of data. This will be exacerbated when your camera is out in direct sunlight on a hot sunny day trackside.

When the cards do start to heat up, as a method of protecting itself from overheating, your camera will slow down write speed which will also trigger buffering.

So keep in mind that high temperatures can impact the camera’s overall performance, including buffering. If you find this happening, particularly during a hot day trackside, put your camera in the shade while not using it to reduce its temperature.

Wrap Up

As a motorsport photographer, more so than any other genre of photography, you are almost certainly going to experience camera buffering at some point. Being a high-action sport, we tend to push that element of cameras harder than most other photographers.

But by understanding what buffering is and what can cause it, you can take steps with both the equipment that you use and your shooting technique to minimise the impact that buffering can have while trackside.