Canon R3 RAW movie confusion

[SamShisho]

Hello. I have some confusion about recording RAW video with Canon R3. I found some information in the user manual, but I still need to clarify how the different settings affect the image quality.

When I'm in video mode and the recording format is set to RAW, I can still enable various settings such as: Canon Log, HDR PQ, or even leave all these settings off. According to the user manual, "RAW movies are raw, uncompressed data from the image sensor that is written to the card", but I see a huge difference in dynamic range, noise reduction, and sharpness in captured video files. I found that turning on Canon log produced the most expected results: a noisy but crisp image with high dynamic range. My understanding is that the log settings should not affect the original RAW data and should simply be included in the file metadata for post-production or monitoring purposes. I've made some tests developing RAW in DaVinci Resolve where I can set the gamma to log 3 or log 2 in the RAW tab, and once my color space transform (CST) is adjusted accordingly, I get a completely identical image for both log curves. This is completely normal and expected since I am applying the same log curve in the RAW tab and the "de log" curve in the CST. I also used Canon Cinema RAW Development software and got the same results as expected.

So RAW is RAW, right? Just clear sensor data? My tests with different settings showed that this is not the case. Turning off all the additional settings in the camera (no log, no HDR PQ, no tone priority) gives me an image with noise reduction and narrow (video like) dynamic range. With the HDR PQ setting turned on, the results are better, but the dynamic range is still lower compared to Canon log. Therefore, in all settings combinations except Canon log, I see a lot of processing of RAW data before it is written to the card. So can anyone help me to understand what's actually going on with RAW movie recording on the R3 and how the data is processed before being written to the memory card? Also what kind of workflows is expected for the settings like no log or HDR PQ with reduced dynamic range and noise reduction baked in RAW? 

As far as I understand, RAW data can be developed using different gamma curves designed for different workflows. For example, for on-set log (using LUTs) or HDR monitoring, proper CST in post-production, etc.

[Hazel_T]

Hi SamShisho,

As patrick521f mentioned when the camera is set to record RAW video it is the RAW light data, but when things like Canon Log or HDR PQ are enabled they do get saved into the file during processing. That is why the manual recommends that if you are prioritizing gradation in highlights it is best to enable Canon Log 3. Since the log profiles have a higher dynamic range they record a wider range of light data in the RAW file.

As far as workflow is concerned it can vary depending on what you are trying to do. If you want to do minimal editing and color grading using RAW with no LOG or HDR PQ may be best. In that case the file would still have enough light information that you can adjust as needed, but for the most part it would look how you shot it. If you want to use specific LUTs, do more color grading, or keep more information in highlights and lowlights we would recommend using a Canon Log profile. If you are shooting video to be shown on HDR monitors we would recommend using the HDR PQ profile. Since all of those files types are still RAW files the color grading and editing process for the files would be similar for each. The main difference would be how much processing you want to do.