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Reddit
reddit.com › r/cinematography › what are s-log, c-log, etc?
r/cinematography on Reddit: What are S-log, C-log, etc?
October 16, 2013 -

Probably an amateur question, but reading American Cinematographer, I occasionally come across mention of "gamma function," S-log, C-log, and other logs. I was wondering what exactly these are, and what purpose they serve and so on? Thanks!

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S-log is referring to an uncorrected sensor output that is flat and low in contrast. This image is taken into a color corrector where the colorist has more control over what colors he chooses to accentuate and the detail in the blacks and highlights is preserved. On most video cameras a Gamma Curve called REC709 is applied which brings the image levels close to what we see with our eyes, this is great for the average user, but for those who want more control, it is better to bypass the default in camera processing. C-log just refers to Canon's "log" shooting mode.
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Log is a format that compresses data very efficiently into the storage available. Every stop of dynamic range gets the same perceptual storage space, as opposed to linear gamma which is how the sensor sees the world and is very inefficient. (Someone here linked to my article that explains why.) The reason log looks flat is because you're often cramming 10-14 stops into the Rec 709 HD spec, which was only meant for about six stops initially. That means every two stops is crammed into a space meant for one, which lowers contrast considerably. Log refers to a logarithmically-encoded gamma curve. Gamma controls contrast and is separate from color space, which is something completely different although most log curves are meant to work within a specific color space (such as Sony's S-Log2 and S-Gamut). Log is not meant to be viewed directly: it is a storage medium only. You need to apply a LUT or some sort of gamma correction so that it looks proper on a Rec 709 display. (Rec 709 is the standard for HD broadcast that enables an image shot on a Rec 709-complaint camera to look normal on a monitor.) Viewing it directly results in a flat, colorless image. Log is NOT uncorrected sensor output. You'll never actually see that. Even viewing "raw" in cameras like REDs isn't raw, because raw is just Bayer pattern information that isn't viewable at all by humans on any device without some kind of processing. (If a camera manufacturer says they are showing you "raw" they are not being entirely truthful. They are showing you some representation of raw that has been processed to be viewable on a Rec 709 display but you are not seeing true raw.) Log is a way of processing raw data in such a way that the same information can be encoded in fewer bits. The rule of thumb I've heard is that you can capture the dynamic range of 12-bit raw in 10-bit log. Log is definitely not a replacement for raw as there are things you can do with raw that you can't do with log, such as go back to the same footage years later with a different deBayering algorithm and pull even more information out of it. It's the next best thing, though, and most TV series shoot log because it's a very efficient way to capture a lot of information for grading. (Features tend to capture raw more often than log.) Every manufacturer has their own flavor of log that works slightly differently. In particular, they each put middle gray and 100% white at different points on the gamma curve. It's important to know this as it helps with determining exposure and judging how much dynamic range you are getting above middle gray. Edit: wrote raw instead of log in last paragraph. Ooops.
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Canon Europe
canon-europe.com › professional photography & video › stories
Enhance your filmmaking with Canon Log - Canon Europe
While all of Canon's Cinema EOS Cameras, most XA and XF camcorders and a growing number of mirrorless models offer a variety of Log-based gamma curves designed to retain detail in both the darkest and brightest parts of your footage, Canon Log is capable of far more than this.
Discussions

should i use clog 3 or clog? canon r6

In order of least to most dynamic range is clog, Clog3, clog2.

When Clog3 was added to the R5, I remember tests showing it did unlock more DR of it's sensor.

If the r6 sensor is of similar DR then it too will benefit from Clog 3.

Any log format requires 10bit codec to work well. I assume the R6 forces 10 bit like my R5 does when you enable log?

Log with 8bit could well be worse than rec709. (This is what HLG was made for, 8bit)

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🌐 r/canon
9
4
May 11, 2022
shoot cLOG+sLOG for Color Profile match? or what?- Canon R5c + Sony A7iii ? desperately seeking simplicity
you can never perfectly match it , but i would recommend you shoot both in log and grade in post while manually comparing both grades next to each other. a reminder that 8bit slog WILL break quick , so slog2 is the better option. shooting hlg or any other profiles that isnt log/raw will be harder to fix ( especially on the a7iii) More on reddit.com
🌐 r/videography
17
June 29, 2024
EOS R50 has no C-Log. Alternative profile ?
They limit the lower end cameras in some way. They leaned they lesson from the 5dmii that had full video capability for it’s time. Uncropped and full bitrate video and great color profile. It was such a good deal everyone In Hollywood started to use it. It was even used in marvel movies. There was no need in the cinema line cameras. Now that they do have cinema cameras they can’t have a lower end camera with full video capability. Even the r5 was throttled. More on reddit.com
🌐 r/canon
11
5
June 23, 2023
Is it worth spending money to turn on C-Log on the 5D Mark IV?
What are you shooting video for, weddings, movies, music videos, YouTube? What's your post workflow? More on reddit.com
🌐 r/canon
11
7
July 18, 2024
People also ask

What is the difference between Canon Log, Canon Log 2 and Canon Log 3?

The original Canon Log delivers a dynamic range of approximately 12 stops, Canon Log 2 up to 16 stops, and Canon Log 3 up to 14 stops. Canon Log 2 retains more detail in darker areas than Canon Log 3 but also features an elevated noise floor. Canon Log 3 is easier to grade thanks to producing a cleaner image and retains the same amount of highlight information as Canon Log 2.

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canon-europe.com
canon-europe.com › professional photography & video › stories
Enhance your filmmaking with Canon Log - Canon Europe
What is Canon Log used for?

Canon Log is used to capture video footage that has a wider dynamic range and exposure latitude than standard video. The Canon Log tone curve is applied at the point of capture to retain more details in the highlights and shadows compared to standard video.

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canon-europe.com
canon-europe.com › professional photography & video › stories
Enhance your filmmaking with Canon Log - Canon Europe
Which Canon Log is best for low light?

Canon Log 2 is the ideal choice for when maximum detail is required, particularly in low-light scenes to extract shadow information. However, it will also cause elevated noise in those darker regions of the image and therefore require more time in post-production.

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canon-europe.com
canon-europe.com › professional photography & video › stories
Enhance your filmmaking with Canon Log - Canon Europe
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Fstoppers
fstoppers.com › video-editing › explaining-most-things-about-canon-log-c-log-get-started-filmmaking-684752
Explaining Most of the Things About Canon Log (C-Log) to Get You Started in Filmmaking | Fstoppers
November 23, 2024 - One challenge I've encountered is working with Canon C-Log while filming on the Canon 5D Mark IV. Having the ability to film in C-Log on this camera is both a blessing and a curse. On one hand, you get the benefit of filming in a log profile, which offers a more dynamic range by using a flatter ...
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Canon Community
community.usa.canon.com › t5 › EOS-DSLR-Mirrorless-Cameras › EOS-R-Why-use-C-Log3 › td-p › 474476
EOS R: Why use C Log3? - Canon Community
December 15, 2024 - This is my understanding of log. Shooting in CLOG maximizes the DR a camera's sensor is capable of capturing. Once the video is color graded you have the greatest rendering and control of tonal variance and detail in contrast and shadows.
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Canon Asia
snapshot.canon-asia.com › article › eng › videography-faq-what-is-canon-log
Videography FAQ: What is Canon Log? - SNAPSHOT
September 15, 2023 - It is considered a “gamma”: a function that corrects the difference between how a camera records a digital image and what the human eyes perceive. The following are screenshots from standard Rec.709 and Canon Log 3 footage. What do you notice?
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Pozo Production
pozoproduction.com › blog › demystifying-canon-log-3-capture-stunning-footage-with-your-canon-camera
Demystifying Canon Log 3: Capture Stunning Footage with Your Canon Camera — Pozo Production
December 15, 2025 - C-Log 3 is a powerful log gamma curve, which allows it to capture incredible dynamic range and cinematic quality video. But conquering its intricacies can feel daunting. So I decided to create this guide to help you capture the best possible ...
Find elsewhere
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Sink or Surface
sinkorsurface.com › canon-log
Canon Log — Sink or Surface
This monitoring LUT does not affect the flat image you are shooting – it is just a preview assist. I found this to be a very help feature when trying to expose my image the way I wanted. I tend to shoot my image with a focus on dark shadows and soft highlights. In post production I was worried how much grading the clip would require. I shot a few clips in the neutral picture style (none of these are used in the clip) and the rest in Canon Log to compare the final image.
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Digital Photography Review
dpreview.com › articles › if you shoot log on the canon eos r5, you should shoot c-log3. here's why.
If you shoot Log on the Canon EOS R5, you should shoot C-Log3. Here's why.: DPReview | Photography News, Gear Reviews & Community
April 7, 2021 - Look closer and you'll see that the noise in C-Log3 mode extends the same distance above and below the 128 marker line, which is what you'd expect: noise is variation above and below the 'true' value. But in C-Log mode, it extends upwards by the same amount as C-Log3, but cuts off cleanly just below a value of 128. Canon is using a very high black clipping level to make the darkest tones appear less noisy.
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PetaPixel
petapixel.com › home › equipment › c-log is coming to the canon 5d mark iv
C-Log is Coming to the Canon 5D Mark IV | PetaPixel
March 23, 2017 - C-Log is Canon’s Log Gamma curve that allows you to capture maximal dynamic range from the camera’s sensor in a limited bit-depth video file (as opposed to raw data).
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ShareGrid
sharegrid.com › articles › how-to-shoot-c-log-on-the-canon-5d-mark-iv
How to Shoot C-Log on the Canon 5D Mark IV
October 17, 2025 - Canon has released a (paid) firmware update that finally introduced C-Log to a DSLR that isn’t the overpriced 1D-C. This flat shooting mode is more than a picture profile - it promises to expand the dynamic range of your camera to 12 stops and bring your image much more in line with the Cinema EOS line.
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EOSHD
eoshd.com › news › eoshd-c-log-and-film-simulation-picture-profiles-for-canon
EOSHD C-LOG and Film Simulation Picture Profiles for Canon - EOSHD.com - Filmmaking Gear and Camera Reviews
May 6, 2024 - C-LOG (Custom LOG) greatly extends dynamic range in the shadows to match that of Canon LOG as closely as possible. This means you can expose for the highlights and maximise the dynamic range of your videos.
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Fstoppers
fstoppers.com › education › how-grade-canon-c-log-video-footage-549050
How to Grade Canon C-Log Video Footage | Fstoppers
February 9, 2021 - Log is so named because it refers to a logarithmic function, which in turn refers to the tonal response curve of the mode, which allows for much more dynamic range to be captured — up to 800% more in Canon's case, allowing for a ton more detail ...
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Canon Europe
canon-europe.com › digital cameras › canon eos 5d mark iv
Canon Log Gamma - Canon Europe
Canon Log footage is recorded in a way that’s easy to colour grade. Noise is reduced, especially in shadow areas and when saturation is increased.
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Wondershare
repairit.wondershare.com › camera-error-solution › canon-log.html
Canon Log: What It Is, Variants, Free Download, and More
It's the original version of Canon's logarithmic color profile. It was developed for professional use, balancing ease of use and dynamic range. C-Log is commonly used in Canon's mid-range cameras, the EOS C100 and C300 (mentioned above).
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PremiumBeat
premiumbeat.com › home › video gear › canon log upgrade: should you send in your canon 5d mark iv?
Canon Log Upgrade: Should You Send in Your Canon 5D Mark IV?
May 1, 2018 - However, to keep up with the ... add its C-Log format natively into your camera. Once in, it’s a simple on-and-off setting on your menu. But, there’s one catch: if you don’t specifically pick up an upgrade camera in-store, you have to send your camera to Canon, and they will add the update. While Canon is secretive ...
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Rodrigo Polo
rodrigopolo.com › 2020 › 09 › 29 › canon-log-the-right-way
Canon Log the right way - Rodrigo Polo
December 24, 2025 - Enabling LOG: This is one of the most important steps and one of the most undocumented ones, enabling C-log on the Canon EOS 5D Mark IV with Canon Log make the camera record video internally in C-Log 1 color space with Rec.709 gamma using 8 bits, same with the Canon EOS R which uses C-Log 1 color space and Rec.709 gamma in 8 bits, but by enabling 10 bits (which only records externally), it enables another option: “Color Matrix”, which can be either “EOS Original” or “Neutral”. “EOS Original” works only in Rec.709 gamma, “Neutral” records in Rec.2020 and Rec.709, and here comes the crazy part, internal recording and HDMI signal are always full range, not “legal/video/partial-range”, but Adobe Premiere doesn’t interprete the Atomos Ninja V videos correctly, only DaVinci Resolve has the option to choose the range of the video.
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CINECOLOR
cinecolor.io › products › canon-c-log
CANON C-LOG – CINECOLOR
The LUTs included in this download pack are designed to convert C-Log footage to Rec 709 on any of the following cameras: ... The download pack features two separate LUTs - one for use on Canon mirrorless cameras (R5/R6), the other for use on Canon cinema cameras (C70/200/300/500).
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EOSHD
eoshd.com › store › eoshd-c-log1
EOSHD C-LOG and Film Profiles for Canon DSLR and mirrorless cameras - EOSHD.com - Filmmaking Gear and Camera Reviews
November 29, 2023 - The EOSHD C-LOG and Film Profiles pack installs a “Canon LOG” picture style on cameras previously without it, plus a range of film simulation modes.
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SNAPSHOT
snapshot.asia.canon › en › article › videography-faq-what-is-canon-log
Videography FAQ: What is Canon Log?
September 14, 2023 - It is known as "log" as it encodes along a logarithmic scale instead of a linear one. The resulting footage contains more information on tone variations that are visible to us, which is also why they appear to have less contrast straight out of the camera. ... - High-contrast scenes - Bright scenes where highlight details are important (e.g. wedding dresses outdoors) - Productions that require colour grading · As Canon Log recording preserves more tonal information than standard recording, it is ideal for high-contrast scenes where you want to retain both shadow and highlight details.