Specifications

Overall improvement in
image quality
Image-recording quality
One of the many respects in
which EOS DIGIT
AL cameras
have made continuous progress
is that their low-noise CMOS
sensors have gained megapixels.
At the same time, various
image-processing features have
been incorporated and image
quality has been improving
apace. The EOS-1D Mark IV
has effectively built upon this.
Overall image quality is clearly improved with both image sensor advances (16 Megapixels,
gapless microlenses and so forth) and image processing function upgrades. The default
settings apply high ISO speed noise reduction, Auto Lighting Optimizer and lens
peripheral illumination correction. In the case of previous cameras, noise reduction at
high ISO speeds greatly reduced the maximum burst during continuous shooting.
However, with the EOS-1D Mark IV and DIGIC 4, this drawback has been eliminated
(except at the “Strong” setting).
Some notes on perceived image quality are appropriate here. First, images shot with the
EOS-1D Mark IV tend to reveal blur and defocus more easily than images shot with
the EOS-1D Mark III or EOS-1D Mark II, especially when viewed at the same size
(for example, when viewing at 100% on a computer monitor). After all, the EOS-1D
Mark IV provides 16.1 Megapixels — approximately 1.6 times more than the EOS-1D
Mark III (10.1 Megapixels) and approximately 2 times more than the EOS-1D Mark II
(8.2 Megapixels).
As long as final print size is the same, the visible effects of blur and defocus are the same
regardless of pixel count. However, it is becoming popular to view images on computer
monitors; thus, clients and photographers are increasingly concerned about blur and defocus
in images shot with high-resolution cameras. EOS-1D Mark II and EOS-1D Mark III
users should understand the increased likelihood of blur and/or defocus when using high-
resolution cameras. To prevent these image defects, photographers should use faster shutter
speeds at high ISO settings and/or shoot with IS (Image Stabilizer) lenses.
As shown in the table here, there are nineteen image sizes to choose from. As with the
EOS-1D Mark III, the JPEG quality (compression rate) can be set to one of ten levels for
each of the L, M1, M2 and S sizes.
85
IV–23. IMAGE PROCESSING AND RECORDING
Technology High Image Quality Effects
1. Approx. 16.10
Megapixel CMOS
High resolution, low noise
2. 14-bit A/D conversion,
signal processing
Excellent gradation
3. High ISO speed noise
reduction
Low noise at all ISO speeds
4. Auto Lighting
Optimizer
Automatic correction to obtain
favorable brightness and
contrast
5. Lens peripheral
illumination correction
Automatic correction of
peripheral light fall-off