Optics
At the professional end of the 35mm film-camera spectrum, Canon is renowned for
the quality of their optics. While we don't know the details of the A5's lens
construction (other than a notation in the documentation that it is an all-glass,
aspheric design), its performance certainly seemed worthy of the Canon heritage.
With a focal length equivalent to a 35mm lens on a 35mm camera, the fast f2.5
lens captures a slightly wider than "normal" field of view. (Moderate
wide-angle lenses of this type are the norm for most point and shoot cameras,
whether film or digital. In most point and shoot applications, the ability to
fit more of the subject into the frame is a decided plus.)
As we go to "press" ("web"?) with this review, we're waiting
for confirmation back from Canon on the A5's lens aperture: The spec sheet states
that it is a "f2.5" lens, giving no indication of any smaller aperture.
(This has been amended to indicate a minimum aperture of f11, as of 5/20/98.)
The lens autofocuses from 20 inches (50cm) to infinity in "normal"
mode, and from 3.5 to 20 inches (9 to 50 cm) in "macro" mode. The
macro mode provides for close-ups of small objects, covering an area of roughly
2.4 x 3.2 inches (6.2 x 8.2 cm) at closest approach. (For reference, the small
brooch in the "macro" test shot is about 1.05 inches (27 mm) wide.)
This is exceptionally good macro performance for a point and shoot camera, although
the slightly wide-angle lens makes for shorter working distances than would
a longer focal length.
A very welcome feature on the A5 was its built-in illuminator for the passive
autofocus system: When shooting in low light levels, the camera projects a bright,
striped beam from an on-board LED onto the subject, just before the shutter
fires. This provides a visible "target" for the autofocus system,
even in total darkness. Low-light autofocus capability (or the apparent lack
thereof) on various digital camera models has been a hot topic of discussion
in internet news groups. The autofocus illuminator of the A5 still won't save
you from blurred pictures caused by camera shake (see our note below, under
"exposure"), but should almost completely banish the problem of achieving
correct focus under low-light conditions.
Exposure
The PowerShot A5 is rated at an equivalent ISO speed of either 100 or 400, depending
on the image size selected: Large-size images are captured with an effective
ISO speed of 100, while the smaller image size uses "binning" on the
CCD array to increase the effective sensitivity to ISO 400. Unfortunately, we
didn't have the opportunity to test the high-sensitivity ISO 400 mode: We didn't
realize the higher sensitivity was only available in the low-resolution mode,
and so performed most of our testing at the higher resolution. It's interesting
though, that we found ourselves exclaiming over the A5's low-light performance,
even at the high-resolution setting.
With a shutter speed range of 1/6 to 1/750 seconds, Canon rates the usable
"metering range" of the camera as extending from EV 5 to EV 16.5.
(When we first received our review unit, Canon had rated at EV 7.6 - 16.5, which
we felt was far too conservative on the low end. Since then, they've amended
the specification to extend down to EV 5, a value consistent with our own testing.)
The autoexposure system works through the lens (TTL), and so is less likely
to be affected by stray light than otherwise. As noted earlier, the camera automatically
chooses the best combination of f-stop and shutter speed for the situation at
hand. A 10 second self-timer gives the photographer time to get into the picture
him/herself.
IMPORTANT NOTE: The 1/6 second lower limit on shutter speed can be a great
help in getting shots in conditions that would otherwise be too dark. This is
a long exposure though, well beyond most people's ability to hold the camera
steady enough to render a sharp image. Use a tripod when it's that dark! A few
pros may venture to hand-hold a 1/6 second exposure, but it's just about guaranteed
that most amateurs will have a hard time below 1/30 or even 1/60. 'Nuff said...
Like any autoexposure system, that of the PowerShot A5 is subject to being
"fooled" by unusual subjects, whether a light object against a dark
background, a backlit subject, or one that's unusually uniform in overall brightness
(such as a snow scene). To accommodate these situations, Canon includes an exposure
adjustment control with a range of +/- 2 f-stop (EV value) in 1/3 f-stop increments,
to accommodate these situations. Thus, if you think the situation calls for
it, you can request more or less exposure by adjusting the exposure-compensation
setting.
While the range and fine control of the exposure-compensation on the A5 was
excellent, we found the procedure for setting it to be rather vexing: To begin
with, exposure compensation can only be selected when the camera is operating
in "program" mode, requiring the mode dial to be set accordingly prior
to the exposure. (In fairness though, this is also a blessing, as the camera
remembers the program-mode settings from one time to the next, allowing you
to switch back and forth between exposure-compensation and full automatic operation
very quickly.) Our biggest complaint with the exposure compensation system though,
was the number of back-panel menu/button operations we had to cycle through
to effect a change. We counted no fewer than 6 button-pushes needed to change
the exposure compensation setting. For the record, we much prefer exposure compensation
adjustments that can be made "on the fly," without navigating a series
of menus. Despite our gripes about the user interface though, we really liked
the degree of control afforded by the 1/3-stop increments, and the wide +/-
2EV adjustment range.
We also liked the focus/exposure lock function of the A5, that allows you to
pre-set the exposure prior to the shot itself: Pressing the shutter button halfway
actuates the autofocus and autoexposure systems, without triggering the shutter
itself. Once the exposure and focus is set in this fashion, they will stay "locked"
at the selected settings as long as you continue to hold down the shutter button.
With this feature, you can easily accommodate off-center subjects by turning
to center them, locking the focus and exposure, then turning back to frame the
shot to your liking before firing the shutter.
The built-in automatic flash has a working range of 8 inches to 11.5 feet (0.2
to 3.5 meters), and offers the standard set of operating modes, including "red-eye"
reduction, force fill, automatic, and of course "off," for those situations
in which you want the camera to just do its best with the light available.
The A5's white-balance compensation is automatic, and does a good job of correcting
for widely varying lighting conditions. The "indoor portrait" test
shot retained enough of the warmth of the incandescent lighting to preserve
the original "feeling," without the color cast overpowering the colors
of the subject.
In its normal operating mode, the PowerShot A5 cycles fairly rapidly between
exposures, even in high-resolution mode: We timed the minimum interval between
exposures at about 3 seconds. (This is quite a bit faster than most digital
cameras, particularly higher-resolution ones.) If this isn't fast enough for
you, the camera also has a "continuous" mode, in which the camera
will record up to 15 frames at one-second intervals, as long as the shutter
button is held down, and sufficient memory is free. Images captured in continuous
mode are only stored at the small size of 512x384 pixels though.
Operation and User Interface
The PowerShot A5 makes extensive use of its bright, clear LCD panel for user-interface
functions, as well as image preview/review. The camera is controlled by a top-mounted,
thumb-operated "mode dial," and a total of six pushbuttons plus the
shutter release button.
One of the first surprises we encountered with the A5's user interface was
the option to set the language used for the menus to our choice of no less than
10 different languages! (English, German, French, Netherlands, Dutch, Swiss,
Italian, Norwegian, Swedish, or Spanish) Being only monolingual even on our
best days, we opted for English. (It turns out our review unit had the European
ROM set, hence the broad range of languages. US versions will only support English,
French, German, and Japanese.) The language menu is accessed by setting the
control knob to Play mode (see below), and then pressing the Set and Macro/Jump
buttons simultaneously.
Menus controlling various camera functions can be accessed in most camera modes
by pressing the "menu" button on the back panel. The contents of the
menu displayed will vary, depending on the mode the camera happens to be in
at the time.
Major camera modes are selected via the top-mounted "mode dial" thumbwheel
that also serves as the power switch (the camera is off when the dial is set
to the "Locked" position. Available camera modes are automatic or
"program" (manual) image acquisition, "stitch assist" mode
for panoramic or mosaic-shooting support, play mode, "multi" mode,
and PC mode. Turning the camera on by rotating the mode dial out of the locked
position automatically retracts the protective metal lens cover.
Record Modes
"Auto" mode is the setting you'll probably use for most of your picture-taking:
In this mode, focus, exposure, white balance, and flash operation are all automatically
set by the camera itself. No modification of the automatic settings is provided
for, that capability being reserved for "program" mode. Auto mode
also limits you to the "large" image size, although you can select
either of the two levels of compression that are available. Auto mode does allow
you to use the A5's macro capability, however.
In "Program" mode, you can manually control the flash setting, turning
it on (forced or "fill" flash), off, or enabling the red-eye reduction
function. In this mode, focus, exposure, and white balance are still automatically
controlled, although you can override the automatic exposure control by setting
an exposure-compensation value of up to +/- 2EV units, as described earlier.
Program mode also allows you to select the "small" image format, as
well as the CCD Raw (no compression) image-storage mode. Finally, Program mode
allows you to select either single-shot or continuous shooting, or the self-timer
function.
At first, we found the need to switch to "program" mode to make even
the simplest adjustment annoying, but we soon came to appreciate the ability
to preserve custom camera settings, and to switch rapidly between the custom
setup and the fully automatic defaults. - The "program" mode settings
are stored separately, so you can (for instance) adjust the settings for indoor,
non-flash shooting, perhaps including some exposure compensation, and then quickly
switch back and forth between the default setting (which would use the flash)
and the custom non-flash configuration with a flick of your thumb on the control
wheel. We actually found this capability quite useful in various shooting situations.
While in either Auto or Program modes, the control menu presents functions
relevant to image recording. You can select between two different image compression
levels for file storage, or turn the "Review" function of the LCD
panel on or off. (When Review is enabled, the LCD illuminates briefly after
each shot is taken to show you what you just captured. You can also turn the
LCD on or off manually at any time by pressing the rear-panel "LCD"
button.) The Record menu also allows you to reset the system of file numbers
(described below, under image storage) assigned to images.
The Record menu also branches to a "setup" sub-menu, allowing control
of LCD brightness, audible alerts, power saving functions, overall camera reset,
and date/time setting.
Play Mode
Once you've captured images, you'll of course want to view them. This is accomplished
by selecting either "Play" or "Multi" mode with the mode
dial. Operation of these two modes is very similar, the only difference being
that the "multi" mode displays images as 9 thumbnails at a time. In
play mode, the "+" and "=" buttons display the next or previous
recorded image, while the Macro/Jump button selects "jump" mode, in
which the +/- buttons skip to the last or first image on the CF card, respectively.
In multi mode, images are displayed in groups of nine, and the currently-selected
image is indicated by a green border. You can move the selection box forward
or back one image at a time by pressing the + or - button, or to the next or
previous group of nine images when jump mode is enabled. When you switch from
Multi back to Play mode, the currently-selected image will be displayed full-size
on the LCD screen.
In Play mode, the menu system provides a variety of functions relevant to viewing
or reviewing your images, and also supports image-marking for subsequent direct
printing via a Canon photo-quality printer.
The first entry on the Play menu is "show info," which displays the
current image number, total number of images on the CF card, file number, creation
date & time, and protection setting icon. (Another Play menu entry lets
you "protect" selected images, so they won't be erased when an "erase
all" function is performed.)
The "slide show" Play menu entry lets you set the camera to scroll
through images stored in memory, specifying how long each is displayed, and
whether the show will loop back to the beginning when it reaches the end. This
feature is becoming increasingly common on digital cameras, but Canon has taken
it a step further by not only allowing you to mark which images to include in
a slide show, but also by providing for three different slide shows to be held
in the camera simultaneously. Images on the CF card may appear in one, all,
some, or none of the three shows interchangeably. Of course, you can also select
"all images" when you want to cycle through the entire memory card.
Options for display time can be set to Manual (using the +/- buttons), or 3,
5, or 10-second intervals per slide. Slide shows always display images in the
order in which they were stored on the CF card.
Storage management is provided by the "erase" function. With it,
you can erase images individually, while scrolling through thumbnails of the
images on the card, or all at once. As mentioned earlier, you may optionally
"protect" some images so that they will survive an "erase all"
function.
We briefly mentioned earlier that the A5 can be used with a small photo printer,
also marketed by Canon. We don't have specifications for it, but the CD-200
printer can accept CF cards from the A5 directly, to provide continuous-tone
prints approximating conventional prints of the sort you'd get at a drugstore.
In similar fashion to marking/unmarking images for slide shows, you can also
mark/unmark pictures to be printed on the CD-200. Once the desired image files
have been marked, you simply remove the CF card from the camera, plug it into
the printer, and hit the Print button - the printer does the rest, independently
of the camera.
Setup functions accessible from the Play menu include those described previously
for the Record mode, plus options for setting the date/time, formatting a CF
card, and choosing the menu language.
Stitch Assist Mode
A number of digital cameras now provide features that support the creation of
"panoramas" by stitching-together multiple images. Here again though,
Canon has gone most of the industry one better: Not only does the PowerShot
A5 support conventional panoramas, including both horizontal and vertical camera
orientations, but it offers a unique 2x2 matrix stitching mode as well. Like
"program" mode, stitch assist mode also enables several manual camera
functions, including flash mode selection, and macro operation.
In all the stitching modes, the A5 leaves a portion of the previous image (or
images, in the case of the 2x2 matrix) on the LCD screen, while running the
LCD as a "live" viewfinder showing what the camera is currently pointed
at. Having the adjoining piece(s) of the panorama or matrix available on-screen
while you're framing the next shot is a tremendous help in achieving good alignment
between adjacent images, a critical requirement for good final "stitch"
results. You'll still probably want to use a tripod and possibly even one of
the special pan heads sold for such purposes, rather than hand-holding the camera,
but even with a tripod, the stitch assist is very helpful. Finally, the A5 offers
the capability to re-shoot an image that's already part of a panorama, if you're
not happy with the orientation, exposure, etc. As far as we know, this ability
to drop back into the middle of a sequence of panorama shots to re-shoot a bad
image is unique to Canon and the A5.
As we mentioned, direct support in the camera for assembling a 2x2 matrix of
images is unique in our experience. The net result is a very high resolution
image. (You'll necessarily lose some image area to the required overlap between
adjacent images, but you can easily achieve 1600 x 1200 images in this manner.)
Image Storage and Interface
The PowerShot A5 stores images on a removable CompactFlash card, with a capacious
8 MB unit included as standard equipment. These cards are quite compact, although
not as much so as the SSFDC "SmartMedia" cards used in some cameras.
The advantage of the CF cards though, is that they are available in very large
sizes (as of this writing, up to 48 meg), for quite reasonable prices. Adapters
allowing CF cards to be read in standard PC-card slots on laptops are available
from either Canon or third parties, and well worth the modest cost if your computer
has PC-card slots: Downloads via the PC slot take seconds, as compared to minutes
for transfers over a serial cable.
The maximum number of images that can be stored on each card varies quite a
bit, depending on the combination of image size and compression level selected.
As mentioned earlier, the A5 saves images as standard JPEG files (making it
a "finished file" camera) at two different image sizes (1024x768 and
512x384) and two different compression settings (normal and fine), all selectable
by the user. A fifth option is to store image in a "CCD Raw mode, in which
the raw data from the CCD is stored directly on the card, without any in-camera
processing. The Raw mode saves uncompressed files of 960x768 pixels, in a proprietary
format. Average file sizes range from 940 KB for the Raw mode through 180 KB
for Large/Fine images, to 85 KB for Large/Normal mode, all the way down to 30
KB for Small/Normal mode. With the included 8MB CF card, these file sizes translate
to a capacity of 8 - 236 images per card. The large memory capacity will doubtless
encourage most people to save images in the Large/Fine mode, allowing an average
of 44 images per card.
As a minor side note, we liked the fact that we could easily insert or remove
the CF card while the camera was mounted on a tripod. Not a big thing, but some
cameras use a bottom-mounted latch for the CF socket, meaning you have to unmount
it from a tripod in order to pull the card. We also liked the consecutive numbering
system for the image files: The camera keeps a running count of exposures, and
attaches a unique number to each image. Images are automatically placed in folders
on the CF card, and a new folder is created for every 50 image files. Thus,
when you download the images onto your hard disk, you never have problems with
image files having the same name overwriting each other. Whenever you change
the camera's battery, the file count jumps to the next 50-unit block. As mentioned
earlier, this file count can be manually reset at any time via the Record menu
interface.
Data can be downloaded from the camera via a standard serial interface, at
a maximum speed of 115 Kbaud. Download of a typical Large/Fine mode image took
about 18 seconds on our standard 133MHz, non-MMX Pentium PC. (Standard-quality
images take about half as long to download.) Canon provides two pieces of software
for downloading images from the camera: A Photoshop(tm) acquire plug-in for
Mac users, and a TWAIN driver for the Windows crowd. On their respective platforms,
these programs provide pretty universal coverage: Many Mac-based imaging programs
support the Photoshop plug-in standard, while TWAIN support is nearly universal
under Windows.
Video Out
In addition to the serial computer interface, the PowerShot A5 also has a connector
for displaying images via standard NTSC video. This is a capability we've generally
found more useful than we first expected: Connected to a TV with a video input
jack, the A5 becomes a portable presentation machine! Since you can upload images
back into the camera, you can select the best/most appropriate shots, put titles
on them with the included PhotoImpact (Windows) software, load them back into
the camera, and then play them back for a presentation. As frequent business
travelers, we've also found digital cameras a great way for the family back
home to feel more connected with our business activities: A "slide show"
of sights and people from a business trip is great for sharing the events of
the trip with the kids. (And with the spouse left behind!)
Power
The PowerShot A5 can be powered either by an (included) high-capacity rechargeable
NiMH battery pack, or by a standard 2CR5 lithium battery (available at most
camera stores). Additional NiMH battery packs can be purchased separately from
Canon. This combination strikes us as a good working solution, and the inclusion
of the NiMH battery pack as standard equipment is especially welcome: Our standard
recommendation for new digital camera owners is to buy a set of high-capacity
NiMH AA cells. We found the Canon NiMH battery pack provided good power longevity,
and recharged quickly in the provided AC adapter/charger unit. With a second
battery pack, you could literally shoot continuously, with one pack charging
while the other was in the camera.
The ability to use a standard 2CR5 lithium cell for "emergency backup"
power is very welcome too: The cell is small enough to not constitute an onerous
burden for the roving photographer, and the exceptional shelf-life of lithium
batteries (measured in years) means that a single backup battery could last
the life of the camera. (A word to the wise though: Even a fully-charged NiMH
pack has a fairly limited shelf-life, due to their tendency to self-discharge
- Be sure to give your NiMH packs a boost before any extended outings!)
The A5's battery charger also serves as an AC adapter, through the use of a
dummy battery pack that connects via a cord to the charger unit. That's right:
A dummy battery pack! - The contraption looks exactly like the standard battery
pack, only it has a cord extending from the bottom of it. To use it, you just
insert it into the camera in place of the normal pack, and plug the cord into
the charger. Although we can't say why, given its faintly Rube-Goldbergish appearance,
we actually liked the "dummy battery" better than the standard plug-the-cord-into-the-tiny-socket
approach of most cameras. By contrast though, some users may find it inconvenient
to physically remove the battery every time they want to run from AC power.
One thing we didn't like about the arrangement was the inability to both power
the camera via the adapter and charge a battery simultaneously: You can only
do one or the other.
IMPORTANT NOTE (For first-time A5 users): This is so embarrassing that we almost
didn't include it, but finally decided that the grief it might save our readers
would be well-worth our deflated egos. When we first received our eval sample
of the A5, we immediately tore into the packaging, slapped the battery and CF
card into the unit, and . . . nothing! Deadness, total lack of electronic activity.
We were within a hairsbreadth of calling Canon when we happened to slide the
latch on the battery compartment cover into the "locked" position.
Voila! - It turns out there's a switch hidden in the battery compartment cover,
and the camera won't power-up unless the cover is locked. For some reason, we
found the action of locking the battery compartment completely unintuitive,
perhaps because it latches shut on its own even if the lock isn't set. There
- we've humiliated ourselves publicly, but probably saved thousands of readers
five minutes of frustration. (Not to mention saved Canon at least a few hundred
tech-support calls!)
Included Software
Canon is unusual among digital camera companies, in that much of the software
they provide with their cameras is private-labeled and available only from them.
While unusual, this isn't at all a bad thing, because Canon's proprietary software
is very functional. The overall suite of applications favors the Windows platform
somewhat, but all important capabilities are available on the Mac as well (excepting
only the slide-show upload function). Standard applications bundled with the
PowerShot A5 include Adobe's PhotoDeluxe version 2.0 (Mac and Windows), and
ULead's PhotoImpact 4.0 (Windows only). Canon's own products include the panorama
and matrix-stitching program PhotoStitch (version 2.1 for Windows, 2.0 for the
Mac); an unusual "album" photo-organizer program called TimeTunnel
(version 2.2 for Windows, 1.6 for the Mac); SlideShow Maker (Windows only),
an application for assembling slide shows to upload back to the camera for playback
via the video output; and Zoom Browser (Windows only), an enhanced image organizer/viewer/downloader
application. Also provided are version 2.2 of Canon's Photoshop(tm) plug-in
for the Mac, and version 2.2 of their TWAIN driver for Windows systems.
We have to admit that we haven't played extensively with the A5's software,
due to the extremely short time we had the system in-house. (Our testing was
conducted very early in the A5's product cycle, when there were only 6 evaluation
units in the US, so the we had to get everything done in a couple of days.)
In our admittedly limited testing though, we found the PhotoStitch software
to work quite well, although as with most such applications, a tripod is really
a requirement, even with the help of the camera's stitch assist mode.
On other fronts, "TimeTunnel" is an interesting concept, deriving
its name in which images are presented as thumbnails arranged spatially according
to when the original image was taken. This is an interesting approach that makes
sense conceptually, but we frankly found it more confusing than useful. We unfortunately
had only very limited contact with Zoom Browser, and none at all with Slide
Show Maker.
Test Results
As with all Imaging Resource camera tests, we encourage you to let your own
eyes be the judge of how well the devices performed: Explore the links at the
bottom of this page, to see how well the PowerShot A5 performed, and how its
images compare to other cameras you may be considering buying.
Overall, we were consistently impressed with the image quality of the A5: We
predict that this will be a very successful camera, as it combines appealing
ergonomics and a strong feature set with absolutely first-rate imaging.
As with virtually every digital point & shoot camera we've tested, we found
the A5's viewfinder slightly inaccurate: The area shown in the viewfinder is
slightly smaller than that captured by the sensor. The LCD screen is ever so
slightly more accurate, displaying a tiny amount more image area than does the
optical viewfinder. Both LCD and optical viewfinders are slightly biased toward
the top of the scene, meaning that your images will end up offset downward by
2-3% of the picture height. We're really nit-picking here though, as both LCD
and optical viewfinders on the PowerShot A5 are among the most accurate we've
tested.
Using the "WG-18" ISO test standard, the PowerShot A5's visual resolution
measured a very good ~550 line pairs per picture height in both the vertical
and horizontal directions, although the vertical resolution showed a slight
advantage. (Whenever we can dig out from under the load of cameras waiting for
us to test, we'll post an article elsewhere on the site explaining image resolution,
and this new international standard for resolution measurement.)
In real picture-taking situations, the PowerShot A5 proved itself a superb
performer, rendering good detail and excellent color in all conditions. (Look
at the colors of the flowers in the outdoor portrait shot, the excellent skin
tones in the "musicians" image, and the well-balanced color in the
house image.) You can get a good idea of the camera's detail-handling capability
by looking at the standard house image. The "Davebox" test image reveals
slightly under-saturated colors, but very good tonal rendition, with detail
preserved in both moderate highlights and shadows. (Notice that almost every
swatch of the long vertical grayscale wedge is visible, and that the delicate
pastels in the Q60 target are preserved down to row "C.")
The PowerShot A5's macro capability was especially impressive for a non-zoom-lens
camera: At its closest working distance of 3.5 inches (8.9 cm) (!) it captured
an area of 2.4 x 3.2 inches (6.2 x 8.2 cm). (The small brooch in the "macro"
test shot is about 1.05 (27mm) wide.) While not approaching the "microscopic"
macro capabilities of some zoom-equipped cameras, the A5 is an absolutely stellar
performer in this area: If you need high-quality macro images at an affordable
price, this alone could swing you to the PowerShot A5.
Conclusion
We found the Canon PowerShot A5 to be an exceptionally appealing digital camera.
It offers very good image quality in an uncommonly compact package, with a very
rugged feel. It provides exceptional macro capability, as well as some of the
best low-light performance we've seen to date. (This article was written in
mid-May, 1998.) Nice touches include the standard-equipment NiMH battery pack
and charger, and the inclusion of the relatively large 8 MB CF memory card.
Overall, this would be an excellent choice for anyone looking for good image
quality in a fixed focal-length digital camera at an attractive price point.
(It's initial "street price" is projected at $699.)
Reader Sample Images!
Do you have a PowerShot A5 camera? If you'll post an album of your
samples on one of the photo-sharing services and email us at photos@imaging-resource.com,
we'll list the album here for others to see!
For More Info:
View the data sheet for the PowerShot A5
View the test images from the PowerShot A5

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