Noise Reduction; Highlight Tone Priority - Canon EOS 1D Mark III - Digital Camera SLR User Manual

By having 2 processors handle the workload, image processing is now approximately
1.5x faster; Compact Flash™ access speed is now 1.3x faster, and SD card access is
now 2x faster compared to the EOS-1D Mark II
Processors has also allowed analog-to-digital conversion to improve from 12 to 14 bits
per channel, meaning that tonal gradation for RAW images is now divided into 16,384
separate levels per channel rather than 4,096. When saved as a 16-bit TIFF image, the
image retains the full range of tones obtained with 14 bits. Also, JPEG images, at 8 bits
per color, are generated from the 14-bit data. Tonal skipping is thereby reduced
substantially, improving gradation and overall image quality.

Noise Reduction

Noise reduction for long exposures is equivalent to that on the EOS-1D Mark II
[C. Fn II-1; 1: Auto] is set, 1 sec. and longer exposures will undergo noise reduction
automatically, depending on the amount of noise detected in the image data. If [C. Fn II-1;
2: On] is set, all 1 sec. and longer exposures will undergo noise reduction.
Now, noise reduction for pictures taken at a high ISO speed is provided via [C. Fn II-2].
Although this feature works at all ISO speeds, it is especially effective for high ISO speeds.
At low ISO speeds, noise reduction is not really necessary. However, applying noise
reduction can reduce noise within shadow areas taken under low light.
Hilight Tone Priority This new feature extends the dynamic range of highlights by about one stop and improves
gradation within highlight areas. By expanding the range from the correct exposure level
(18% gray) to the maximum allowable highlight level, the gradation from the grays to
the highlights becomes smoother and loss in highlight detail is minimized. If [C.Fn II-3;
1: Enable] is set, the settable ISO speed range will be ISO 200- 3200. The display will
show "2oo" with the zeros in smaller characters. Depending on shooting conditions,
noise in the shadow areas may increase slightly.
III. IMAGE QUALITY IMPROVEMENTS
Image-processing Sequence Diagram
10M
14-bit A/D
conversion
CMOS
Highlight Tone Priority: ON
. The extra power of Dual DIGIC III Image
N
DDR
SDRAM
Front-end
Dual
processing
"DIGIC III"
circuit
Highlight Tone Priority: OFF
CF card
SD card
. When
N
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