Canon USA (www.usa.canon.com)
has updated its G-series line of cameras with the new PowerShot G7, priced
at $599.99. This newest entry has ten million effective pixels, utilizing
a CCD imager. The imager is based on Canon's 1/1.8-inch technology, a
form factor that has been in use for some time. The PowerShot G7 employs
a 6X optical zoom lens, with a focal length of 7.4-44.4mm f/2.8-4.8 (35mm
film equivalent: 35-210mm). This is one of the longer zoom lenses for
a pocket digital camera; a majority of digital cameras have a zoom factor
of 3X to 4X. The PowerShot pairs this 6X lens with an optical viewfinder,
rather than the electronic viewfinder that is found on so many other
long-zoom lens cameras. Although the camera does have a 4X digital zoom
feature, I would not recommend using it to any great extent. I have found
that it does not enhance your photographs much. You can give it a try
if the subject of your photograph is far away and you cannot get closer,
but be prepared for some disappointment.
Previous versions of the G-series cameras featured an LCD monitor that
could be rotated and flipped from its docked position on the back of the
camera body. The G7 features a brilliant 2.5-inch TFT monitor, with fifteen
levels of brightness control, and fixed in a permanent position. This may
not be the most important feature in making a purchase decision, but it
is very convenient and makes it much easier to take candid photographs.
The monitor offers excellent color and good visibility in daylight. The
only time I had any trouble was when I was shooting in bright, open sunlight,
but then, every LCD monitor reacts the same in these circumstances. In
every other situation, the camera provided good viewing.
The PowerShot G7 offers you a wide selection of shooting modes. These include
the standard Manual (M), the Shutter-Priority (Tv), Aperture-Priority (Av)
and Program, when the camera selects both the shutter speed and the ƒ-stop.
The camera can set shutter speeds from fifteen seconds to an action-stopping
1/2000th of a second. In Shutter-Priority mode, the shutter speeds are
set via the control dial on the back of the camera body. A thermometer-style
tape display pops up on the LCD monitor to show you what shutter speed
you are setting. It is a large, clear display, making it very easy for
you to confirm what you have selected. In Aperture-Priority mode, aperture
selection, ranging from ƒ2.8 to ƒ8, is affected the same way
shutter speed is.
These four shooting modes are only the beginning of the PowerShot G7's
shooting set-ups. In addition to having a Movie setting, you can turn the
mode selection dial to "SCN" or Special Scene. The G7 has a series
of sixteen scene-specific shooting scenarios in what Canon calls the Image
zone, plus "Stitch Assist" which helps you to stitch images together.
These Special Scenes set the camera up for specific situations or locations,
such as taking someone's portrait in Portrait mode, shooting in the snow
in Snow mode or on the sand in Beach mode. There is even one scene for
boosting the PowerShot G7's ISO to a setting of 3200.
ISO is normally set via a dial on the top of the camera body. The ISO range
of the G7 is nominally ISO 80 to ISO 1600. You have to remember that as
you increase your ISO, i.e., your camera's sensitivity to light, you may
have to make adjustments to your shutter speed or aperture to compensate,
depending an your shooting mode.
The PowerShot G7 saves image files in one of several JPEG compression levels
-- Superfine, Fine and Normal -- with the Superfine offering the smallest
amount of JPEG compression and Normal the greatest compression. You also
can select the number of pixels used to record your image, as high as 3648
X 2736 pixels in the Large (L) setting, and as low as 640 X 480 pixels
in the Small (S) setting. The camera also can be set to a widescreen capture
of 3648 X 2048, in a 16:9 aspect ratio.
If you have the camera set in Movie mode, you can select both the frame
rate and pixel count for recording your movies. Movies can be set from
160 X 120 pixels up to 1024 X 768 pixels. You can access frame rates at
either fifteen frames per second or thirty frames per second. Files are
saved in a Quicktime format.
But knowing the feature set of a camera is only part of the story. You
also want to know about the quality of the photographs you will get. In
the case of the PowerShot G7, their quality will tell you a lot.
I am most impressed with the great color fidelity the G7 offers. I took
several pictures using a GretagMacbeth ColorChecker (www.gretagmacbeth.com).
Each shot was set to a different ISO setting. Regardless of the ISO, the
G7 was consistent in its presentation of the colors represented on the
ColorChecker. The three additive primary colors, Red (R), Green (G) and
Blue (B), were sharp and vibrant, as were the subtractive primaries, Cyan
(C), Magenta (M) and Yellow (Y). The fourth subtractive primary Black (K),
as part of the grayscale, was sharply delineated, as were the other grayscale
patches.
I did run into one problem, however, in carrying out my tests. As I increased
the ISO above 80 (Figure
1), I started to see too much electronic noise
in the pictures. By the time I got to an ISO setting of 1600, my images
appeared to have a bad case of the measles (Figure
2). Skin tones had developed
a severe case of acne and blue sky now looked as if it had been stabbed
with a marking pen. Every image at the higher ISO settings was overrun
with a splotchy, mottled appearance. Your pictures should be fine as long
as you keep the G7 at a nominal setting of ISO 80 or 100, but I cannot
recommend using the higher settings.
In my opinion, all this electronic noise has cropped up because digital
cameras now offer a pixel count that far exceeds the needs of the average
photographer. You do not need ten million pixels to create a good image
of your grandmother or to capture a memorable scene at the Grand Canyon.
With the never-ending race to cram more and more pixels on the same amount
of silicon, the camera’s imager, picture quality will continue to
suffer.
The bottom line for the Canon PowerShot G7? It is, indeed, a worthy successor
in the G-series line of cameras. I miss some of the old features, bemoan
some of the new, but in the end, I would give this camera a strong "buy" recommendation.
©2007 Rick Oldano
All Rights Reserved
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