Digic Iii And 14-Bit A/D Conversion; Image Recording And Processing - Canon EOS 40D White Paper

DIGIC III and 14-bit A/D
Conversion
Image Recording and
Processing
Following its appearance on the EOS-1D Mark III (in tandem form), the EOS 40D also
uses Canon's latest image processor, the DIGIC III. It retains the DIGIC II's widely
admired image detail, natural colors and high speed, while providing 1.7 times faster
signal processing speed.
The analog output signal from the imaging element is converted into a digital signal
with 14 bits (16,384 colors) per channel instead of the previous 12 bits (4,096 colors).
The result is digital data with finer gradation. With RAW/sRAW images recorded at 14
bits, one can use Canon DPP (Digital Photo Professional) software to process and save
the image as a 16-bit TIFF image. This yields the maximum range of colors afforded by
14-bit processing. Also, because images recorded in JPEG (8 bits per color) are also
generated from 14-bit RAW data, there are fewer blown highlights than before and
gradation is excellent. Even in the case of highly saturated subjects or subjects with
high contrast and clear differences between light and dark features, high quality color
reproduction and smooth tone rendition from highlights to shadows are possible.
When compared to the EOS 30D, the image quality of the EOS 40D is appreciably better.
Resolution is now higher, with approximately 10.1 megapixels versus the 8.2 megapixels
of the EOS 30D. Image quality is higher because of the DIGIC III and 14-bit image pro-
cessing. Noise reduction of high ISO shots, first offered on the EOS-1D Mark III, is
enabled via C.Fn II-2. Highlight Tone Priority (ISO range 200-1600*), makes gradation
finer from grays to highlights, reducing the likelihood of blown high values. This feature,
too, first appeared on the EOS-1D Mark III. It is set on the EOS 40D via C.Fn II-3.
* Standard output sensitivity. Recommended exposure index.
On the image-recording quality selection screen, when one
selects the image-recording quality, the respective pixel
count (horizontal x vertical) and the number of shots possible
with the current CF card are now displayed as well. Also,
sRAW (approximately 2.50 megapixels), another feature
from the EOS-1D Mark III, has been added as a highly useful
image-recording quality option.
Small RAW can also be recorded simulta-
neously with any JPEG recording quality.
For image size and number of possible
shots with their respective image-recording
settings, see the chart given here.
III. PERFORMANCE
Quality Selection Screen
Fig. 37 Quality selection screen
Selected image-recording quality and
the respective pixels are displayed
Image-recording
Image File Size Possible Shots
Quality [Approx. MB] [Approx.]
L (Large/Fine) 3.5
L (Large/Fine)
1.8
2.1
M (Medium/Fine)
M (Medium/Fine)
1.1
1.2
S (Small/Fine)
0.7
S (Small/Fine)
RAW 12.4
12.4+3.5
L (Large)
12.4+1.8
L (Large)
12.4+2.1
RAW+
M (Medium)
12.4+1.1
M (Medium)
12.4+1.2
S (Small)
12.4+0.7
S (Small)
7.1
sRAW
L (Large) 7.1+3.5
L (Large) 7.1+1.8
7.1+2.1
sRAW+
M (Medium)
M (Medium) 7.1+1.1
7.1+1.2
S (Small)
7.1+0.7
S (Small)
The number of possible shots (battery life) and continuous shooting speed are based on Canon's testing
standards and a 1GB CF card. The size of one image, number of possible shots (battery life), and contin-
uous shooting speed are based on JPEG quality 8, ISO 100, and the Standard Picture Style. (These fig-
ures vary depending on the subject, memory card brands, ISO speed, Picture Style, etc.)
Possible shots
Maximum Burst
[Approx.]
High- Low-
Speed Speed
274 75 205
523 171
523
454 140 454
854 303 854
779 271 779
625
1451 1451
76 17 20
59 16
14
16
66 14
65 14 16
16
70 14
16
69 14
72 20 16
17
135 34
90 21
17
107 17 22
17 22
103
116 17 23
115 17 24
124
25
17
6