Video shot with a DSLR or mirrorless digicam is recorded linearly. A lot of the video’s data is within the brightest f/cease, leaving little or no information for the shadows. Log codecs easy out this uneven distribution of picture data.
Understanding linear video is the muse for attending to know and love taking pictures Log.
Most cameras, video and nonetheless alike, report video in a linear style in 8-bit. A linear video is a type of JPEG seize. What does this imply?
JPEGs are 8-bit recordsdata. They maintain 256 steps of knowledge per pixel, in comparison with 1024 steps for a 10-bit file and 4096 steps for a 12-bit file. JPEGs are compressed types of pictures which have restricted latitude for adjusting publicity and colour correction. The construction of the info in JPEGs places half of the info the digicam data to the file within the brightest f/cease of publicity.
The chart of a six f/cease dynamic vary sensor exhibits that there are solely 4 pixels of knowledge for the darkest shadows which means it’s near unimaginable to retain any element in them.
The distribution graph under covers the info distribution for an eight f/cease dynamic vary sensor. The data proven in each charts is similar.
Log video recording modes change the straight “linear curve” proven above to redistribute the pixel data extra evenly from shadows to highlights. The chart under exhibits how the curve impacts the pixel tonal values throughout the dynamic vary of the eight f/cease seize.
Kodak movie scanner
Kodak’s Cineon movie scanning system originated the usage of Log video. It scanned movie right into a Log model that was much like the density of the unique movie being scanned. This method gave essentially the most data from every body of movie that could possibly be saved as video. Log video has a variety of shades of grey; it is vitally low distinction and must be corrected to view on a monitor.
Digicam Log variations
ARRI, Sony and Canon video and nonetheless cameras that supply Log captures have their very own type of Log. ARRI is LogC, Sony’s is S-Log and Canon’s is Canon Log (or Clog) that at the moment is available in three variations with differing curves. Clog, Clog2 and Clog 3 are the present variations for Canon movement and nonetheless cameras with high-end video seize options.
Log movies have extra data to make shadow particulars lots higher. Typically selecting to shoot Log video will up the bit depth of the recording to 10 and even 12 bits per pixel. The elevated bit-depth provides the video recordsdata extra picture data than linear video. Excessive bit depth movies are a lot bigger in measurement than linear video.
Log & LUTs (Look Up Tables)
The 2 images under are the identical body from a video shot with a Canon R5 taking pictures Canon log 3 (Clog3) Rec 709. The picture on the left is straight out of the digicam. The picture subsequent to it has the lookup desk (LUT) for the video to convey it into regular colour and publicity. There is no such thing as a colour grading executed to the suitable aspect photograph. It’s all executed with the LUT.
LUTs are a terrific instrument for dealing with all kinds of picture modifications. The gallery under exhibits how LUTs can management publicity in comparison with the as-shot model.
- Prime row: Video as shot, Clog3 Rec 709 Native, Clog3 Rec 709 -1/3 f/cease
- Backside row: Clog3 Rec 709 -2/3 f/cease, Clog3 Rec 709 -1 f/cease, Clog3 Rec 709 -11/3 f/cease
As soon as a LUT has been utilized, the common colour grading instruments in video enhancing software program can be utilized for fine-tuning.
Rec 709 & Rec 2020
Rec 709 is the frequent picture format (CIF) that defines HD tv. It units the side ratio at 16:9, with 1080 lively traces per image and 1920 samples per line with sq. pixels.
Rec 2020 is the CIF that defines ultra-high-definition tv together with 4K and 8K resolutions utilizing sq. pixels in a side ratio of 16:9. It additionally defines a bit depth of 10 or 12 samples per pixel together with a wider colour gamut than Rec 709.
Click on right here to learn extra Video 101
Nonetheless photographers are utilizing the video options of their cameras increasingly. Like me, they in all probability surprise what all the video jargon of their digicam’s menus and manuals imply. Video 101 is written to assist reply these questions.