Canon EOS C300 User manual

© 2013 Canon USA, Inc. All rights reserved.
WHITE PAPER
CINEMA EOS FOR 2K AND HD ORIGINATION
Written by Larry Thorpe
Professional Engineering & Solutions Division, Canon U.S.A., Inc.
For more info:
cinemaeos.usa.canon.com
EOS C300 / EOS C500

Cinema EOS for 2K and HD Origination
Introduction
Canon began a rollout of a family of Cinema EOS cameras in the Fall of 2011. The EOS C300 made its
debut in November 2011 as an HD-only camera that captured digital HD in-camera to Compact Flash
cards. It employed an innovative new Super 35mm 4K image sensor to originate that HD. The EOS C500
followed in 2012 as a digital cine camera having a far broader capability in the digital image formats it
originated. It delivers a choice of 4K, 2K, or HD uncompressed files for external recording. It is intended
for very high-end origination of movies or television production. Finally, the EOS C100 flanks the family
–at the lower-budget end –it too, being an HD-only camera.
This paper is intended to focus on the important differences between the EOS C500 and the EOS C300 –
purely in the context of HD or 2K digital origination. The 4K capabilities of the C500 will be addressed in
a separate paper.
Imaging Section of EOS C500 and EOS C300
These two cameras share identical imaging sections –in terms of deployment of the Super 35mm 4K
CMOS image sensor specially developed by Canon for digital motion imaging. Accordingly, the two
cameras share in common the exceptional high sensitivity , wide dynamic range, and high picture
sharpness produced by this image sensor.
Figure 1 The same 4K CMOS image sensor is used in both the C500 and the C300 digital
cine cameras
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Cinema EOS for 2K and HD Origination
Introduction
Canon began a rollout of a family of Cinema EOS cameras in the Fall of 2011. The EOS C300 made its
debut in November 2011 as an HD-only camera that captured digital HD in-camera to Compact Flash
cards. It employed an innovative new Super 35mm 4K image sensor to originate that HD. The EOS C500
followed in 2012 as a digital cine camera having a far broader capability in the digital image formats it
originated. It delivers a choice of 4K, 2K, or HD uncompressed files for external recording. It is intended
for very high-end origination of movies or television production. Finally, the EOS C100 flanks the family
–at the lower-budget end –it too, being an HD-only camera.
This paper is intended to focus on the important differences between the EOS C500 and the EOS C300 –
purely in the context of HD or 2K digital origination. The 4K capabilities of the C500 will be addressed in
a separate paper.
Imaging Section of EOS C500 and EOS C300
These two cameras share identical imaging sections –in terms of deployment of the Super 35mm 4K
CMOS image sensor specially developed by Canon for digital motion imaging. Accordingly, the two
cameras share in common the exceptional high sensitivity , wide dynamic range, and high picture
sharpness produced by this image sensor.
Figure 1 The same 4K CMOS image sensor is used in both the C500 and the C300 digital
cine cameras
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Most large-format single-sensor cameras employs the Bayer CFA (color filter array) to encode the RGB
color information. Typically, the RAW outputs from these cameras constitute a single output signal
which is subsequently debayered to structure the three separate RGB video components. This process
entails some degree of reconstruction errors depending upon the sophistication of the debayering
algorithm. The EOS C500 and C300 cameras also employ the classic Bayer CFA –but we deploy an
alternative strategy to the construction of the separate HD / 2K RGB frames as described in Reference
[1]. No demosaicing processes whatever are employed.
Within the 4K CMOS image sensor there is an innovative readout mechanism that directly reads out four
2K video components in parallel. They are R, Gr, Gb, and B (each at 1920 x 1080 or, in the case of
the C500, they can be selected as 2048 x 1080 depending upon the particular choice of “2K”). Because
of the nature of the Bayer pattern the two green components Gr and Gb are spatially offset with respect
to each other. When they are summed to form the final 2K Green component the traditional first order
horizontal and vertical sidebands cancel which eliminate a major source of aliasing. As a consequence
the optical low pass filter can be better optimized for an unusually high green MTF. For more
information on how this works please see Reference [2].
The Sensitometric characteristics of the two cameras are identical as described in Table 1 and are more
fully described in Reference [3].
Table 1
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In-Camera Recording in the EOS C500 and C300
Both camera employ identical in-camera recording capabilities. They both deploy an MPEG-2 codec to
do this recording.
Figure 3 Summarizing the salient features of the in-camera recording within the C500 and C300
More specific details of the in-camera recording are summarized in table 2. It will be noted that both
are “worldcams” in that they originate and record all of the internationally standardized digital HD
formats. In the case of the C300 this recording can constitute the primary program capture. In the case
of C500 it is used as an HD proxy of the separately and externally recorded uncompressed 4K/2K/HD
material –for use in the offline editing process.
Table 2
EOS C300 EOS 500
In-Camera Recording In-Camera recording
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In-Camera Recording in the EOS C500 and C300
Both camera employ identical in-camera recording capabilities. They both deploy an MPEG-2 codec to
do this recording.
Figure 3 Summarizing the salient features of the in-camera recording within the C500 and C300
More specific details of the in-camera recording are summarized in table 2. It will be noted that both
are “worldcams” in that they originate and record all of the internationally standardized digital HD
formats. In the case of the C300 this recording can constitute the primary program capture. In the case
of C500 it is used as an HD proxy of the separately and externally recorded uncompressed 4K/2K/HD
material –for use in the offline editing process.
Table 2
EOS C300 EOS 500
In-Camera Recording In-Camera recording
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EOS C500 as High performance 2K or HD Acquisition System
Where the C300 is intended as a compact camcorder with on board MPEG-2 recording, the C500 is
intended to originate considerably higher performance 2K or HD digital component video which is then
captured on a broad choice of world renowned external digital recorders.Comparing Figure 4 with the
previous Figure 3 will reveal the significant elevation in the 2K/HD performance of the C500.
Figure 4 Summarizing the salient specifications within the C500 processing that sharply
distinguish it from the C300
What is Unique about the 2K or HD Video Components in EOS C500
There is a distinct benefit to structuring the RGB video components in the manner described –in terms
of delivering unprecedented overall image quality in the 2K / HD RAW output:
1. Full and equal bandwidth RGB 4:4:4 video components
2. Selectable as 12-bit or 10-bit RGB components
3. Because no debayering process is required –any form of reconstruction errors and associated
aliasing artifacts are totally avoided
4. No compression is applied to these RAW signals
5. The direct readout of the four separate video components: R Gr Gb B as a 4 : 4 : 4 : 4 set
of 1920 x 1080 (or 2048 x 1080) is followed by the digital summation of the two green
components Gr and Gb –to produce the “Super Green” that has been one of the striking
differentiators of the C300, C100, and C500 cameras. That special Green video has (a)
enhanced dynamic range, (b) higher resolution, and (c) virtually zero aliasing –see Ref [2].
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6. RGB 444 at 12-bit is available at all international standard frame rates up to 60P. If desired, this
can be switched to 10-bit.
7. If higher frame rates than 60P are sought –the EOS C500 can be switched from 12-bit RGB 4:4:4
to 10-bit YUV 4:2:2 and this component set can be originated as high as 120 progressive fps
(selectable in 2-frame steps from 62 to 120 fps as shown in Table 4).
8. Canon Log [4] is applied to each of the RGB components which are then delivered as 12-bit RAW
components for recording.
9. To restore a linear light representation from Canon-Log in postproduction a conversion to linear
space should be in accordance with the mathematics shown in Reference [4]
External Recording of 2K or HD
The EOS C500 delivers these RAW RGB video components to an external recorder via a standardized 3G
SDI serial interface. A single 3G SDI interface will support all progressive frame rates up to 29.97P. Two
such interfaces will support RGB components up to 59.94P. Table 3 summarizes the primary
characteristics of the component video that can be delivered to the external recorders. Note that the
C500 only originates progressive frame rates in contrast to the C300 (the C500 in-camera interlaced
formats are derived from the progressive)
Table 3
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EOS C500 2K / HD Slow and Fast Motion Recording
In addition to the standardized frame rates shown in Table 3, the C500 can be switched into a variable
frame rate mode which supports slow motion playback from the recorders, or alternatively, motion that
has been speeded up for special effects. Table 4 summarizes the modes of operation that are
supported.
Table 4
Summary
The C500 is different to other large-format single-sensor digital cinematography cameras. It
directly originates from a 4K Bayer CFA Super35mm image sensor three full bandwidth RGB 2K
or HD video components that are exceptionally clean of artifacts. Combined with the
exceptional sensitivity of the camera and its 12-bit depth and 12-stop exposure latitude –this is
2K / HD at its very best. The summation of the two green components endows the final
matriced Luma with unusually high sharpness and freedom from aliasing across the 2K
passband. This, in turn, allows any downstream image enhancement to be dispensed with –
further contributing to the cleanliness of the imagery and providing a natural sharpness that is
especially valuable to the reproduction of human facial close-ups.
References
[1] Canon White Paper: “New Super 35mm CMOS Sensor for Cine Motion Imaging”
[2] Canon White Paper: “RGB Resolution Considerations in a New CMOS Image Sensor for Cine
Motion Imaging”.
[3] Canon White Paper: “Sensitometric Characteristics of the EOS C300 Digital Cine Camera”
[4] Canon White Paper: “Canon-Log Cine Optoelectronic Transfer Function”
All of these listed White Papers can be found on the Canon website via the following URL:
http://www.learn.usa.canon.com/resources/artices/2012/cinemaeos_white_papers.shtml
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