Cinema RAW Light explained

More and more filmmakers are seeing the light. That's Cinema RAW Light, the Canon-developed compact RAW file format that allows creatives to achieve results that are simply not possible with other codecs.

Filming in RAW gives you more options in post-production, but the file format has been hard to accommodate in the past. Canon Cinema RAW Light, first introduced with the release of the Canon EOS C200 video camera, makes using RAW faster and easier than ever.

RAW filming ensures optimum control over picture quality and enables creative and technical decisions to be made later in post-production. Previously, that flexibility had come at the price of large file sizes, making the storage and transfer of 4K RAW files on location and in the edit suite a challenge.

Canon's Cinema RAW Light format alleviates this problem, offering a significant reduction in file size without sacrificing image quality or grading and compositing headroom. Featured in the entire current Cinema EOS range, the Cinema RAW Light format allows filmmakers to realise the widest dynamic range of the camera's sensor in a file that's approximately a third to a fifth of the size of a standard Cinema RAW file.

"RAW scares a lot of people because they think it's hard to handle, but it's not," says advertising filmmaker Brett Danton, a convert to the Cinema RAW Light format. His thoughts are echoed by Ollie Kenchington, who runs an award-winning corporate film production agency and is one of the world's best-known colour grading experts. "From a colourist's point of view Cinema RAW Light is a fantastic codec to work with – there's just so much data inside of it. But it's also a very low CPU load codec, which means that it can play back very easily. Those two things are kind of the holy grail: lots and lots of data, but lightweight enough to edit with a laptop."

Canon Cinema EOS cameras offer scalable 12-bit Cinema RAW Light LT, ST and HQ options, each offering a unique balance of fidelity and bitrate, as well as a variety of sensor modes / resolutions including Full Frame, Super 35mm and Super 16mm.

Canon Log 2 is designed to deliver up to 16+ stops of dynamic range, minimising the loss of detail in the darkest and brightest parts of the image. It provides a versatile base for grading, but Cinema RAW Light unlocks more options in post-production. Like Cinema RAW Light, Log footage starts out as raw sensor data but then the gamma curve and processing parameters are baked into it at the point of capture. This doesn't happen with a Cinema RAW Light file (.CRM). In fact, it isn't a movie file at all, it's simply a container for all that raw sensor data, and it has to be unpacked, debayered and modified in software before being exported in a choice of formats appropriate for ingestion into popular post-production packages.

However, as the processing of a Cinema RAW Light file has to be finished in software rather than in-camera, a number of parameters can be adjusted long after the footage has been recorded. For example, brightness, white balance and sharpness can be fine-tuned in Canon's Cinema RAW Development software. Also, a different colour space and gamma to those set on the camera at the time of shooting can be assigned to the exported file, for example, applying Log 2 (with compatible software) to enable the maximum 16+ stops of dynamic range to be achieved.

"Being able to shift between Canon Log 2 and 3 in post-production without any degradation is a big benefit of the Cinema RAW Light format," says Aron. "If you had bright outdoor scenes that were more suitable for Canon Log 3 and other low light or high contrast scenes that were more appropriate for Canon Log 2, you can simply switch those on the fly in post."

The huge amount of information that's captured in Cinema RAW Light is a clear advantage over heavily compressed formats. "Cinema RAW Light enables cinematographers to take advantage of the full capability of the camera, creating a RAW file that conforms to known workflows, but with the added benefit of capturing internally to recording media," Aron says.

Shooting 4K at a bit depth of 10/12-bits at 1Gbps produces data-rich files that deliver high-quality results even after a substantial degree of manipulation in post. Cinema RAW Light enables you to achieve the look associated with RAW files at a fraction of their size, making a RAW workflow more accessible than ever before.

"The big thing for me isn't so much that it's RAW per se, it's more the non-chroma subsampled image it delivers," says Ollie. "So you get the full RGB 4:4:4 colour information, which is really important for certain projects."

Cinema RAW Light features

• Compact and lightweight format
• Three data rate options available: LT, ST and HQ
• 10/12 bit RAW
• Up to 16+ Stops of Dynamic Range when selecting Canon Log 2
• Accurate and smooth tone reproduction
• Delivers the camera's natural and full colour response

With the introduction of the Canon EOS R5 C, filmmakers were able to realise the benefits of a Cinema RAW Light workflow in a smaller camera and at 8K resolution. What's more, it provided a choice of different Cinema RAW Light formats: HQ (High Quality), ST (Standard) and LT (Light). "All three are 12-bit RAW, with no chroma subsampling," says Aron. "The only difference is in the data rate."

As Aron explains, Canon introduced three different versions of Cinema RAW Light in order to give filmmakers more flexibility. "For a lot of people, shooting 8K/25p RAW at 2.6Gbps in the original Canon EOS R5 was quite demanding. It's a lot of data to put on your CFexpress cards and then a lot for the computer to process, and in general the projects would get very large in terms of file size. But now we've introduced LT at 1070Mbps in the EOS R5 C, it's making it more accessible.

"The ST and HQ options are for people who don't want to compromise on image quality, and who have the professional workflows to deal with higher bit rates. This could be useful when cropping the image significantly or generating high-end visual effects. Overall, though, the difference in image quality between the three formats is fairly small and almost impossible to tell with the naked eye in a simple scene such as an interview scenario."

Ollie agrees. "It feels like there's a little bit more clarity to ST when compared to LT, but it is very subtle and it really isn't something that I suspect a non-colourist would notice," he says. "I think if I was shooting a project where colour was paramount and we needed that full RGB, and maybe we were planning to apply some sharpening in post, over and above what you would normally do with developing RAW, then I think ST would be the route I would go down for certain projects. But LT is perfectly decent and if you're just after a really robust 4:4:4 codec that's full of colour information, and not just using extra data that you're not really going to benefit from, then LT is perfect."

It's worth noting that the HQ mode is available only when shooting in Super 35mm and not in Full Frame (on the EOS R5 C). That's simply because of the limitations of CFexpress 2.0 Type B media. "We can record up to 2.6Gbps onto those cards reliably, and we don't exceed that," explains Aron. "So we're able to unleash 8K 60p with Cinema RAW Light LT, and if you want to go to Cinema RAW Light ST for even more data then you can go up to 8K 30p. If you decide to raise the data rate with Cinema RAW Light HQ, then you'll be restricted to 5.9K and Super 35mm, but this still delivers an exceptional amount of detail for any professional 4K workflow." Alternatively, it is possible to shoot 6K Full Frame Cinema RAW Light HQ on the EOS C400.

Canon has worked with its partners to ensure that the Cinema RAW Light file format is supported natively by a range of popular non-linear editing systems (NLEs), meaning that CRM files can be viewed, edited and graded in software without the need to create an intermediary file, saving both time and disk space.

"In many ways RAW codecs are all the same and they all have similar workflows in post," says Ollie. "But certainly, in my experience, Cinema RAW Light is one of the easiest to play back on not particularly powerful computers.

"I'm always a bit surprised at how well it responds, given that it is a RAW codec. It almost feels like working with Apple ProRes 4444, which is a non-RAW full RGB codec. But you can, of course, change ISO and sharpening and noise reduction and lift gamma and gain, and all these other things that you can do as part of the first grade because it is a RAW format.

"The fact that there's an internal proxy recording workflow available in Cinema EOS cameras is also great. It solves an editing problem, because you're getting a half-resolution XF-AVC video file recorded with the same timecode and the same file name as the Cinema RAW Light file. So you can do all of your editing with the proxy and then just switch over to the Cinema RAW Light file when you're going to do all of your grading and noise reduction at the end."

Brett Danton was among the first filmmakers to use Cinema RAW Light while recording this Jaguar F-PACE SUV commercial in New Zealand on pre-production Canon EOS C200 cameras.

The production schedule required visits to multiple locations in a short space of time, meaning that a mobile setup and easy data management were priorities. It's a combination for which the large amounts of data and smaller RAW file size offered by Cinema RAW Light are perfectly suited. The ability to record RAW internally provided the image quality and flexibility that Brett and his team needed, while the camera's MP4 proxy files meant that offline edits could be made on location and reconformed to RAW when the team returned to the UK.

The shoot took place in a range of weather conditions, but it was essential that the colours of the vehicle were rendered accurately from shot to shot. The wide dynamic range and accurate reproduction afforded by Cinema RAW Light ensured that continuity was maintained between scenes recorded in full sun, rain, snow and fog. Other considerations included green screen and composite VFX, in addition to HDR finishing, all of which benefited from Cinema RAW Light's wide colour space and bit depth.

An example of where Cinema RAW Light shines is in the opening shot of the commercial. The combination of high-contrast sunset scene and VFX stag required both an extensive dynamic range and a detailed file that would ensure no image degradation. Cinema RAW Light provided both, with Brett able to decide, in the comfort of the edit suite, whether Canon Log 2 or Canon Log 3 would produce more shadow detail.

Recording detail in the interior of the dark car and the bright, snow-capped backdrop in a single shot posed its own dynamic range challenges. Brett points out that his colourist would normally need to do a two-pass grade for a scene like this – one for the interior and one for the exterior – and then comp in Flame, the 3D visual effects software. Shooting Cinema RAW Light gives you the option of manipulating the raw sensor data, refining the brightness and expanding the dynamic range of the output file before grading so that it can all be done in a single pass.

Obviously RAW won't be needed in every situation, and even the additional processing required for Canon Log may be a step too far when the priority for clients is a fast turnaround. But when picture quality counts and HDR and VFX-heavy workflows are required, Cinema RAW Light provides the perfect base from which to work.

Because there's no need for external recording units, the shooting process is largely the same as with a compressed codec, although Brett exposes differently in Cinema RAW Light. "With RAW, I'm looking to gather as much information as possible rather than trying to expose for a predetermined look. We decide on the look in post," he says.

"If you're working to finish in HDR, you don't want to blow out highlights. If you've got a subject with a lot of contrast, you've still got to decide where you want the shadow area to sit. Ideally with RAW, you want to lift the shadows a little and not have them sit on the very bottom, because that's where noise can come in. I use my waveform to check I haven't blown highlights in the brightest part of the image, then see if that puts a lot of important stuff into the dark area. Then I might clip the highlight a little more."

Ollie encourages filmmakers to always shoot a colour chart and to get the white balance right on every shot. "People might think getting exposure and colour right doesn't matter with RAW, but it's useful information," he says.

A key advantage of filming in Cinema RAW Light is that the file sizes are small enough to edit. Brett still generates proxy files – an exact copy of your footage in a smaller file size – but mostly uses them for clients to view on set. "I only use proxies to upload as rushes with a LUT dropped on, so clients can have a look," he says.

To make the most of shooting in Cinema RAW Light you need extra storage, higher resolution screens and powerful hardware, but technology in areas such as memory, storage, computer graphics and processing is improving all the time."You can scrub through footage very simply, which is kind of incredible really," adds Ollie. "We've got a file that's full of colour information, it's really rich with data, and yet it's lightweight enough to cut together and work with – even on a laptop. There aren't going to be many systems that struggle. When I was doing a demonstration with the Canon DP-V3120 [a 31-inch 4K HDR professional reference display], which is an incredible monitor, the whole thing was being driven by my 16-inch MacBook Pro. It's quite staggering to think that we can work with these files on a laptop. It opens up all kinds of options."

Canon's Cinema RAW Development software can be used to convert Cinema RAW Light files into a codec that's readable by a range of non-linear editing systems (NLEs). Footage can also be dropped straight into Adobe Premiere Pro and DaVinci Resolve and plugins ensure compatibility with Final Cut Pro X 10.4 from Apple (using the Canon RAW Plugin for Final Cut Pro X) and Media Composer from Avid Technology (via the Canon RAW Plugin for Avid Media Access).

"In terms of cutting and editing, and the grading tools you use for colouring, Cinema RAW Light is no different from any other file," says Ollie. "There is no specific workflow. The different software presents the RAW tools slightly differently. The RAW image doesn't have a gamma applied, so you can make it Rec.709, Canon Log 3, Log 2 or Log."

All these options could be confusing for the less experienced filmmaker – especially when mixing footage from different cameras – but that's when you see the benefit of an all-Canon Cinema RAW Light workflow, adds Brett. "You've got the same flavour of RAW across multiple Canon cameras, so you've got consistency and you know you can match those files together."