Canon C300 Mark II: Testing high dynamic range and the new XF-AVC codecFriday, September 11, 2015 3:10 PM
The second instalment in our series of Canon C300 Mark II blogs sees WTS production specialist/freelance cameraman Patrick van Weeren and Blue 2.0 colourist Damion Katwaroo tell us what they think of the C300 Mark II's dynamic range, and of Canon's new XF-AVC codec.
The Canon C300 Mark II differs significantly from the original C300 in a number of key ways.
In fact, the C300 Mark II should more accurately be seen as a new concept altogether.
Three major changes in the C300 Mark II are the use of CFast 2.0 cards, a 15-stop dynamic range and the new XF-AVC codec.
Recording on CFast 2.0 cards
The new CFAST 2.0 memory cards have write speeds around five times faster than CF. The recording time on the CFast 2.0 cards changes for two reasons: compression quality; and the storage capacity of the card.
The schedule below from Canon white papers show you the average space needed on a card. The camera works with VBR (Variable Bit Rate) so duration can vary slightly.
The camera has the option of using Long GOP XF-AVC recording as well, but I wouldn’t recommend using Long GOP with C-Log 2 footage as the compression doesn’t combine well with colour grading. It's preferable to shoot RAW or XF AVC-I. A 10-bit 50 Mbps 4:2:2 recording will give you around 160 minutes on a 64GB card in HD mode.
Recording proxies on SD
The C300 Mark II can also record separate HD/2K proxies on an SD Card. (Together with the raw output, the camera can actually record three streams from the sensor simultaneously.)
The proxies are in a 4:2:0 colour compression in 8-bit and at H264 Long GOP compression at 35Mb/s (50/59.94p) or 24Mb/s (50/59.94P/29.97P/25P/24/23/98). The proxies are also stored in a .MXF wrapper.
The approximate recording time on a 32GB memory card is 175 min (24Mb/s) and 120min (35Mb/s). The proxy-recording is not available during slow-motion at frame rates higher than 59,94P.
XF-AVC codec gives much better colour representation and excellent skin tones
This was the first time that Blue 2.0 colourist Damion Katwaroo had worked with this codec, and what he saw impressed him – it seems that Canon have created a codec that actually performs well in 4K.
"The colour representation seems to be a lot better" compared to the 8-bit output of the original C300, said Damion. "When applying keys it's a lot cleaner, so overall I think the new camera is producing cleaner images which are a lot easier to grade.
The codec handled the 4K footage well and had remarkably stable colours. You would expect the saturation to increase when you push the contrast, but here the skin tones seemed to be reliable and the footage was ‘clean’ enough to key windows, highlights and shadows easily.
"The skin tones in the scene held up very well," said Damion. "I think this is mainly due to the saturation levels when contrast was added, so when adding a lot of saturation into it, the skin tones reacted very well compared to the surrounding environment. You can get a lot more tonal values in the highlights, and in the lowlights it handled quite well, too."
High dynamic range changes grading approach
The camera’s wide dynamic range – 15 stops – demands a different approach to the grade, said Damion.
Instead of just shadows, mid-tones and highlights, you now have to split the highlights down into three different levels of highlights. Hence the love of over-exposure – the log and codec
handle better when shadows are over-exposed, giving less grain in dark areas.
Don't forget to look out for the other blogs in this Canon C300 Mark II blog series