If you’ve ever exported a video to be published onto YouTube or another online platform, it’s likely you’ve come across Apple ProRes in some way.
Apple ProRes is one of the most popular video codes to shoot and edit with. Previously, Apple made it exclusive to Final Cut Pro to encourage shooters to use Apple’s video editing program. But today, you can use ProRes in Premiere and Avid in addition to Final Cut Pro.
Great, but what is the Apple ProRes, exactly?
Shooting and editing video is very much a science and can become incredibly complicated. I’ve edited in a number of different codecs for close to a decade and can give you the ropes on what sets ProRes apart and what exactly it is.
Here’s what you need to know about the ProRes codec…in 5 minutes.
When you shoot video, the picture must be converted into information and data. This conversion is called encoding. That information must then be properly understood by a piece of software. This process is called decoding. A codec is both an encoder and decoder that turns a video signal into data and then turns around and allows a program to read that data.
Editing in ProRes
ProRes shines in post-production and in video distribution for two main reasons:
- It’s much less taxing to edit with
ProRes compresses files so as each individual frame you capture is lightly compressed (i.e. it does not create a lot of data). This compression means your computer doesn’t need to over exert itself to “unpack” a lot of information (decompress) at once.
- The picture that it delivers can be easily broadcast across a number of different formats at a higher quality
ProRes is a 10-bit codec, which allows for better colors at a more efficient compression rate.
Understanding video BitRate
Bitrate is the amount of information that your camera can write/record to its memory device at a given time. This could be recording to a memory card in the camera or an external recorder. Many shooters choose to use external recorders with a signal running from their camera to the recorder. External recorders bypass the camera’s internal storage or a smaller memory card. A camera’s internal storage is only so large, so this requires greater compression and therefore a lower bitrate.
Most importantly, know that bitrate is not bit depth.
What is bit depth?
And I thought you’d never ask…
Bit depth is code for how many colors the camera sensor can recognize and subsequently record. While shooting video, the camera is capturing light, sending it to a sensor, and telling it to figure out which color is which. The more colors it has to draw from, the more accurate and colorful the picture.
- 12 bit – the highest bit depth for many cameras to shoot with, this is likely overkill for most people and will result in a huge file.
- 10 bit – a quality bit depth that allows for roughly 1,256 shades of color for the camera to recognize
- 8 bit – usually the lowest bit depth offering on the market, allowing for 256 shades of color
What is 4:4:4 and 4:2:2 Chroma Sampling
Without getting too technical, you should know that color images have three channels of information. 4:4:4 provides the most resolution for the color in each of those three channels.
4:2:2 is the “younger brother/sister” of 4:4:4 in that it will provide a perfectly adequate picture for most professional scenarios, including shooting on a green screen. Ideally, you don’t want to shoot in less than 10-bit for a green screen.
Most 10-bit image sensors will sample an image in 4:2:2. This will give you a good amount of color resolution to adjust colors in post and is suitable for most anyone reading this article.
Technically, the below are all ProRes codecs. The numbers, names, and letters associated with them being are referred to as the compression.
Why wouldn’t you shoot and edit with ProRes? Well it’s not quite that simple:
- Not all cameras shoot in ProRes
Many DSLR cameras, say Canon for example, record in their own “native” codecs (XF-AVC for example) and require you to purchase an external recorder to record in ProRes. External recorders can range from $500 – $2,500.
- Not everyone has the file storage
ProRes does a very nice job of maintaining a relatively low file size given the information it is storing and subsequently “writing” to a video editing program. That said, the file sizes are much larger than other codecs, in some cases files can be 10-15 times bigger than say shooting in h.264.
4444 and 4444 XQ
These are the highest quality versions of ProRes, with the XQ being the absolute highest-quality version.
4:4:4 means the camera is able to record an incredible amount of color detail, so much so that it’s almost indistinguishable from the original material.
Officially the most compressed ProRes codec and therefore the lowest picture quality, ProRes proxy is used exclusively for what’s called proxy editing.
This is the lowest quality Apple ProRes codec you’d want to use for anything intended for broadcast or to be distributed publicly. ProRes LT is highly compressed footage that is meant to offer a smaller file size to accommodate those scarce on storage options while providing a decent image.
ProRes 422 HQ vs ProRes 422
These are both high quality codecs that offer 10 bit recording and 422 sampling. Choosing whether to record in 422 HQ or in 422 is a matter of:
- How many colors correcting you intend to do
- Are you shooting in challenging lighting conditions or intend to make stylized color choices in post-production?
- The destination the video is going to appear on
- The bandwidth and storage capacity for your video files
HQ claims to provide lossless quality and is widely adopted across the video industry. 422 non HQ is no slouch but provides some quality loss, with the tradeoff being that it records at a 33% smaller file size (147 Mbps) compared to ProRes HQ (223 Mbps).
In short, if you want to take advantage of the benefits of ProRes but are unsure where to start, ProRes 422 is likely the best entry point for you.
Here is the final chapter in your ProRes crash course—some helpful editing terms to know:
- Proxy Editing – editing with proxies means using lower grade files to edit in your timeline, then syncing these files to the original, high-quality files prior to export. This makes it easier on your computer’s processor as you’re using smaller file sizes. You can then link these smaller file sizes to the original, higher quality files when ready to export (this is possible because they’ll have the same metadata, even if they have different amounts of information).
- Latitude – this is another way of describing the amount of information you have recorded onto a file. Shooting in a high-quality ProRes codec records a lot of information and gives the editor a lot of “latitude” to work with.
- MBps – not to be confused with Mbps (lower case b). MBps (capital B) is how much information is being recorded onto your memory card or a hard drive per second. 8Mbps is equal to 1MBps, so when you see that ProRes 422 HQ shoots in 228Mbps, you can expect to consume 28 megabytes per second (228Mbps / 8) or 1.68GB per minute (28Mbps x 60).
- Transcoding – this is the process of converting one codec (say ProRes) into another (H.264 for example).