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Testing / Performance
*The Canon PowerShot A640 has a Digic II image processor that is included on previous A-series models; this processor typically fares well in terms of color reproduction. Results usually vary with different lenses and sensors and such. We tested the A640 by securing it to a tripod and photographing an industry standard color chart in optimal studio lighting.
The color chart, manufactured by GretagMacbeth, is pictured below but has been modified by Imatest imaging software to show the difference between the original colors of the chart and those same colors produced by the Canon A640. The PowerShot’s colors are depicted as the outer portion of each tile; the inner square corrects the ideal colors for luminance. The vertical rectangle in the center of each tile shows the original color of the chart; this is what colors should look like.
Below is another rendition of the digital camera’s colors. The GretagMacbeth’s colors are shown as squares, and the Canon PowerShot A640’s colors are shown as circles. The line connecting the two shapes depicts the degree of error.
The Canon PowerShot A640 shows fairly realistic colors with a relatively low mean color error of 6.5. Colors were over-saturated by an average of 7.3 percent, which is lower than most compact digital cameras’ colors. The A640’s overall score of 9.23 is impressive for a compact digital camera and shows that it has the capability to reproduce pictures very closely to what is seen with the eye.
**Still Life Scene **
Below is a shot of our still life scene, captured with the Canon PowerShot A640.
*The Canon PowerShot A640 touts the most resolution of any A-series camera with 10.1 megapixels on its 1/1.8-inch image sensor. The sensor is the same size as its predecessor, the A620, that had a 1/1.8-inch CCD but only 7.1 megapixels on it. We tested the PowerShot A640 by using it to photograph an industry standard resolution chart in optimal studio lighting.
The photo above is the sharpest shot we could glean from the A640. We photographed the resolution chart using different focal lengths and apertures to ensure we got the absolute sharpest shot. The image above was taken using an aperture of f/3.5 and a focal length of 21.7mm. Even at its sharpest, the corners of the frame are blurry.
Imatest imaging software determined the sharpest shot and output sharpness results in terms of line widths per picture height (lw/ph). This measurement describes how many alternating black and white lines of equal thickness could fit in the camera’s frame without blurring. The Canon PowerShot A640 resolved 1930 lw/ph horizontally with 9.6 percent oversharpening. It resolved 2163 lw/ph vertically with 5 percent oversharpening.
The Canon A640 performed decently; it captured more details in pictures than its predecessor. The 10.1-megapixel A640 earned a 4.96 overall resolution score.
Noise – Auto ISO* (2.62)
*As with other compact digital cameras, the Canon A640 is equipped with an automatic ISO setting. We tested its ability to meter an optimally lit scene and measured the resultant noise. The metering system worked fine, as it chose an ISO 100 setting. Unfortunately, there is way too much noise at that relatively low sensitivity setting. The Canon PowerShot A640 got a lackluster 2.62 overall auto ISO noise score, which is a new low below the A620’s 5.58 and the A520’s 6.76.
Noise – Manual ISO* (3.79)
*The A640 adds a little more sensitivity than its predecessor offered, but both cameras have the same Digic II image processor. We tested the manual ISO settings from 80-800 and plotted the noise on the following chart with the noise on the vertical axis and the settings on the horizontal axis.
Sadly, there is a lot of noise even at the lower sensitivity settings, so the steady curve doesn’t help at all. The 3.79 overall manual ISO noise score is only slightly lower than the A620’s 4.03 score.
Low Light* (7.0)
*So far, all of our testing has been done with bright studio lights. Because most users won’t have bright lighting around all the time, we tested the Canon A640 in lower lighting conditions of 60, 30, 15, and 5 lux. The first two tests of 60 and 30 lux are more common shooting situations equivalent to photographing a dinner party at a restaurant or the kids in the living room after dusk. We secured the A640 to a tripod, manually set the white balance, and turned off the flash for these images.
Colors remain fairly accurate the darker the lights go, but the color saturation fades from 8.8 percent oversaturated at 60 lux to 4 percent undersaturated at 5 lux. The noise increases as the shutter remains open; this happens on all compact digital cameras. Below is a chart showing just how much noise resides at each shutter speed. The noise is on the vertical axis and the exposure time is on the horizontal axis.
The shutter remains open from 1-15 seconds, and the noise definitely increases but it is not as bad as on other models. The Canon PowerShot A640’s ability to keep subjects illuminated in low light and its decent handling of noise makes it a decent all-around compact digital camera.
***Startup to First Shot (6.5)
*Some of the best pictures are spontaneous – something happens suddenly, and a good, or lucky, photographer gets a great shot. The length of time a camera takes to turn on and be ready to shoot can have a big impact on how lucky a photographer is apt to get. The Canon A640 took 3.5 seconds to get off its first shot after being turned on, in our tests. That’s longer than most cameras we test. Many compact cameras score in the neighborhood of 2 seconds, and DSLRs are usually under a second.
*Shot to Shot (9.32)
*The A640 shoots an average of 1.45 frames per second in burst mode, when set to largest and best quality images. We did not run it long enough to fill a 2 GB memory card (which we were using for testing), but our experience suggested that its buffer keeps up with that shooting speed – it ought to keep shooting until the memory card is full, the batteries run out, or the photographer’s finger gets tired.
*The biggest complaint we hear about compact cameras is that they have long shutter delays – the lag between when the user presses the button and when the shutter clicks is too long. The Canon A640 is not a stellar performer in this respect – in our tests, the A640’s median delay was 0.63 seconds. That’s longer than many competing cameras. A good score for compact cameras is about 0.3 seconds. Users should learn to prefocus when possible, which can shorten the delay.
Canon’s A-series certainly isn’t the most attractive camera line, but it still follows traditional design rules. When viewing from the front, a hand grip protrudes on the left side with the PowerShot A640 logo emblazoned upon it. The labeled Canon 4x zoom lens sits on the right with its specs printed around its edge: "7.3-29.9mm 1:2.8-4.1." The telescoping lens extends in three segments from the body when the camera is powered on, but it still protrudes about a third of an inch when turned off. The outer edge of the lens is serrated and has a light silver color. This band can be taken off by pushing the semi-circular button at the bottom right of the lens and twisting counterclockwise. Taking the band off reveals threading for optional conversion lenses that the A640 is compatible with. Also on this side, halfway up the camera body, is a tiny bump that is hardly noticeable which indicates where the band fits around the lens for replacement. To the top right of the lens is the built-in flash unit, with a "10.0 Megapixels" label beneath it. To the left of the flash is the optical viewfinder that sits just left of the center of the lens. The optical viewfinder and flash units protrude slightly from the rest of the camera body, and it bends back to meld with the top. To the left of the viewfinder is a small AF illuminator and self-timer indicator. This feature sits above the Canon logo, and the built-in microphone that picks up monaural audio for the movie mode.
The back side of the A640’s camera body almost looks like a camcorder. The left side is occupied by a 2.5-inch LCD monitor that flips outward and rotates. On one side is a sturdy casing and a silver Canon logo and the other side is graced with the screen itself. Above the LCD is the optical viewfinder that appears as a tiny circular window with two LEDs to its right. The component protrudes slightly from the camera body, but it is not enough to make it exceptionally comfortable or anything. To the right of the viewfinder is a silver mode dial, and while technically located at the top of the camera, its serrated edge also shows on the back. To the right of the LCD is where the control buttons are crammed into a space about an inch wide and two inches tall. At the top of this space is a small mode switch, placed closer to the LCD that toggles between playback and recording modes. To the switch’s right are nine plastic bumps on the camera body that serve as a rudimentary thumb grip. Below these features are four circular buttons that surround a navigational control. The top two circular buttons operate the exposure compensation/delete (left) and print/transfer (right) functions. The button on the right has a LED in its center to show when it is transferring files to computers or printers. The round navigational dial consists of a circular Func./Set button surrounded by a ring with four dots in the cardinal directions. Above the dial are two icons for flash and the jump function. Below the dial are two more icons for macro and manual focus modes. The two buttons below the navigational control include Disp. on the left and Menu on the right. Overall, the back of the camera is typical of similar models. It is blank and serene on the left side that houses the LCD screen while the right side is overcrowded where the controls are crammed.
**Left Side ***(7.5)*
The left side isn’t particularly gorgeous, but it shows the sturdiness and functionality of the A640. The outer edge of the left side shows the black plastic casing common on this camera’s body. The inner portion of the left side has a shinier, but dark metal panel. It isn’t flat, and it seems to bubble out. Its central backbone has two screws in it, and a large joint shows where the LCD monitor connects to the camera and rotates.
This is the thickest portion of the camera body, meant to make handling more comfortable. The hand grip is constructed mainly from shiny dark metal that makes it slippery. There is a vertical niche toward the front, but this didn’t aid in comfort at all and didn’t seem to do much in terms of function or frill. The rear portion of the left side has a fixed chrome eyelet at the top and a stiff rubber door just below it. The door is connected with two rubber straps, but the outside of the door is already showing signs of wear (tight wrinkles in the corners), and it’s only been opened less than a dozen times. The door is labeled "Digital, A/V Out, DC-in" and has three separate ports beneath it. The door has a tiny strip carved out of its back so users can cram a fingernail in and pry it open. Below the door is a black plastic panel that is totally featureless.
The top shows rounded edges on the front and back with a few components protruding (flash on the front and optical viewfinder on the front and back). The PowerShot A640 logo and a smaller AiAF logo appear on the left side of the top. Towards the right side are several components crammed onto the thicker hand grip. There is an oval-shaped power button with a silver mode dial to its right. A small LED sits below the power button and to the left of the mode dial to show which position on the dial is activated. To the right of the mode dial is a circular web of holes that make up the built-in speaker, and the chrome eyelet is visible from this angle too. In front of the dial and the speaker, on the top of the hand grip, is the shutter release button surrounded by a zoom ring.
The left side of the A640’s bottom is a large door that opens to reveal the battery compartment and SD memory card slot. The door springs open, but it locks tightly with a switch on the door that must be slid toward the front of the camera while simultaneously pushing the door toward the outer edge. Almost in the center of the camera is the plastic tripod socket. The right side is cluttered with boring information like serial numbers and how many volts of power can flow through the camera.
As part of the Canon A-series and to keep with tradition, the A640 has an optical viewfinder. The viewfinder seems to be more of a convention than an actual functional component. The viewfinder provides only a vague resemblance of the captured image. The optical viewfinder zooms just as the lens does, but it certainly doesn’t provide the same view. There are blurry spots around the view, especially around the edges of the frame. The view is horribly inaccurate too. When the viewfinder is zoomed out to its widest (which isn’t very wide at all), the finished image captures more around each edge, and this is the optical viewfinder at its best. When the viewfinder is zoomed in, it cut off about a third of the captured image at the bottom. This is even worse in the macro mode. Photographers who insist on using the optical viewfinder should use the viewfinder only when zoomed out on subjects. Zooming in causes the viewfinder to be terribly inaccurate and makes it impossible to frame subjects properly.
The A640’s LCD monitor is among the largest on the Canon A-series digital cameras. This model’s predecessor, the A620, has a 2-inch LCD that folds out and rotates. While both cameras have folding and rotating LCD monitors, the screens are very different. The Canon A640’s larger 2.5-inch low-temperature polycrystalline silicon LCD screen has a much wider viewing angle. The A620’s screen solarized unless viewed straight on, requiring users to constantly twist and turn the monitor. The newer A640 won’t require as much fussing because the screen can be seen from above, below, and side to side. Images have good contrast and do well even in bright direct light, and that is good because the A640 doesn’t have a brightness adjustment like many other compact digital cameras do. The A620 and A640 both have 115,000 pixels of resolution on their LCD screens, but the limited resolution is spread even thinner on the PowerShot A640. This poor resolution makes manual focusing very difficult, but it is still a better option than the optical viewfinder since it has 100 percent accuracy in its framing. The LCD screen can be turned off or the display info changed from basic to full with the "Disp." button. In the setup menu, users can also add grid lines and/or 3:2 guide lines to really clutter the screen. The Canon A640’s LCD screen has disappointingly low resolution, but its wide view and flexible nature still make it a usable component.
The Canon PowerShot A640 has a built-in flash unit that is fixed to the front of the camera. It sits above the lens in the top right corner of the front. This makes it especially vulnerable to wandering fingertips and will produce a hard-edged shadow to the side of the subject. I snapped at least a few pictures that were half-bright because my left fingers had nowhere to go but in the way of the flash unit. When the top of the navigational control is pushed, only a few flash modes appear: On, Off, and Auto. This isn’t where the options end, though. There are a lot more in the menu system. The shooting menu lets users activate red-eye reduction and slow sync. It also lets users choose whether to fire the flash before the shutter opens or as it opens (1st or 2nd curtain options available in the shooting menu).
The flash is fairly powerful considering that it isn’t a unit that pops up and is relatively small (though also fairly unflattering for the same reasons). It lights up subjects from 1.5-14 ft when the lens is zoomed out and to 10 ft when zoomed in. The flash is also somewhat functional in the macro mode, where it lights from 9.8 inches to 1.5 ft. The flash’s light is nearly centered, but it doesn’t cover the entire frame very evenly. The edges definitely lack the light that reaches the middle. The flash’s power can be adjusted within the Func./Set menu to +/- 2 in 1/3 increments. This is a nice touch for close-ups and portraits when the flash tends to overdo it. Users who find that this flash range won’t cut it for their needs will want to purchase the optional Canon HF-DC1 slave flash that can extend the range to about 30 ft. It costs about a hundred dollars and automatically syncs with the built-in flash unit.
Overall, the Canon PowerShot A640’s flash is very functional, but it will likely need some tweaking with the flash compensation and mode to get the job done right.
A 4x optical zoom lens extends from the front of the camera body with its 7.3-29.2mm measurements. This is equivalent to 35-140mm in the common 35mm format and is longer than the standard compact 3x lens. Users can add even more zoom power with conversion lenses that attach to a threading when the outer rim is removed (via the button to the bottom right of the lens). If users want to pretend they have a tele-converter, there is a digital one available via the recording menu. It is found in the Digital Zoom sub-menu with Standard (4x), 1.4x and 2.3x options on hand. According to Canon’s August 24 press release that introduced the A640, this function "digitally emulates having a traditional tele-converter attached."
The Canon lens has some barrel distortion that shows up at its widest focal length and in macro shooting. It simply bends lines but not as dramatically as with a fish-eye lens. The A640’s lens has maximum apertures of f/2.8 at the 35mm focal length and f/4.1 at the 140mm focal length. This should allow sufficient natural light onto the image sensor, so users won’t have to boost the ISO or lengthen the shutter speed – both of which would increase the amount of noise in the final image. The lens is controlled by a zoom ring that surrounds the shutter release button. The control is large enough that is doesn’t completely cramp the hand to move and is a step up from some PowerShot models. When the lens itself moves, though, it makes quite a sound. It isn’t the chirping bird or a trapped moth sound like on some digital cameras, but it is a loud electronic noise – something that could be used as a special effect on a Hollywood set for an incoming UFO. Overall, the 4x optical zoom lens has a nice range and lots of flexibility with threading and optional conversion lenses.
Design / Layout
Model Design / Appearance*(6.75)*
A look at the A-series lineup shows just how much Canon has tweaked design in the past few years: not much at all. The Canon PowerShot A-series digital cameras have a certain utilitarian aesthetic to them. They all have chunky hand grips, telescoping lenses, optical viewfinders, and thick bodies. Most have folding LCD monitors and similar button and dial layouts. The Canon PowerShot A640 follows these traditional A-series guidelines, but it differs in its body color. Most A-series models – but not all – only come in the typical light silver color. The A640 has a black body that is comprised of plastic and metal panels. There are a few light silver highlights: the lens rim, shutter release button, mode dial, navigational control, etc. The overall appearance of the Canon A640 doesn’t scream "gorgeous," though consumers after something more stylish and trendy will likely gravitate towards Canon's SD-series; however, the SD-series doesn’t come with the same vast amount of manual controls.
Size / Portability*(5.5)*
The Canon PowerShot A640 isn’t a waif of a digital camera. It measures 4.31 x 2.6 x 1.93 inches. It has boxy dimensions, but its edges are rounded and the panels match well together. It weighs in at 8.64 oz (245 g), but that’s without the four AA batteries included. The A640 is much too chunky to slide into a pants pocket comfortably, but it can still be transported in a large coat pocket or hand bag. It doesn’t require a separate camera bag, although that never hurts (especially if you invest in the conversion lenses, slave flash, and other accessories). The A640 has a strap eyelet to attach an included wrist band, but this camera is too heavy to dangle from a wrist. Even if your wrists are incredibly strong, I still wouldn’t trust the flimsy wrist strap.
While consumers may curse the A640 for not being as skinny and portable as other digital cameras, they should forgive it when they handle it. The chunky hand grip keeps your palm from cramping permanently, and the placement of the controls and buttons are all within easy reach. There are a few potential problems, however, the metal hand grip material is slick, and the body is quite heavy. The hand grip shouldn’t be a big problem unless the photographer’s palms are sweating profusely or a coating of sun block was just slathered on. As for the weight of the camera, there’s really no way to change it. Users should make sure they have two hands on the A640 at all times, though.
Control Button / Dial Positioning / Size*(7.0)*
As previously stated, all of the A640’s buttons are nicely placed within easy reach. The zoom ring that surrounds the shutter release button is large, as is the enormous mode dial behind these features. The power switch on the back of the camera is a bit on the small side. The four circular buttons that surround the navigational control are nicely sized and spaced. Everything is properly labeled, although at first glance, the back of the camera looks cluttered because of all the buttons and labels. The navigational control consists of a central Func./Set button with a ring around it. The ring has four dots indicating the directions. When users push on a side, it doesn’t depress as much as one would expect. Still, it did its job and didn’t accidentally navigate to other menus.
This PowerShot has a menu system typical of its relatives. The more frequently used shooting options are located in a menu accessible by the Func./Set button. This menu is loaded with lots of options and a live preview of many of them. The menu is set up so that the items appear on the left edge of the LCD screen, and the options for each item appear to the right along with the live preview.
Other menus can be accessed via the Menu button (makes sense, right?). A menu system appears with tabs at the top dividing the three sub-menus: Recording, Setup, and Custom. There is a gray background, and the tabs are multicolored. The following is the recording menu.
This is the setup menu on the Canon PowerShot A640.
The Canon PowerShot A640 has a custom menu, but it doesn’t have many options. It lets users activate a startup image, startup sound, operation sound, self-timer sound, and shutter sound. There are only "On" and "Off" options for each of these items; this is very different from previous A-series digital cameras. Many A-series models, including the A620 that is being replaced by the A640, had at least three sounds and images to choose from. Sounds included howling dogs and chirping birds on previous cameras. The A640 only has the standard beep though. This boring menu can be spiced up with the included software though. Users can import their own startup image, self-timer noise, and shutter sound, if desired.
Overall, the menu system is intuitive as long as users understand the separation between the Func./Set and Recording menus.
**Ease of Use ***(7.0)*
Canon’s A-series is known for its ease of use, and the Canon PowerShot A640 carries on that characteristic. It is easy to handle with proper sizing and spacing of buttons. The menu system is well organized, and the mode dial streamlines shooting and makes it easy to just point and shoot. Navigation is intuitive with a traditionally styled multi-selector, and users can "jump" through large numbers of pictures with the top of the control. Overall, the Canon PowerShot A640 is easy to use especially considering that it offers manual control too.
The A640’s auto mode is simple to find with the green label on the large mode dial. All other modes are printed in black on the dial, so the auto mode is distinctive. In the auto mode, users can make a few selections in the Func./Set menu: Auto or Hi ISO, all three self-timer options, and the image size and compression options. The recording menu is also available, but it is shortened so that it doesn’t include complicated features like the AF Frame and Flash Sync. Flash and macro options can be activated with the multi-selector too. This makes the Canon A640’s auto mode sound overly complicated, but it really isn’t. Beginners and those who like to avoid hassle will appreciate the auto mode, as it does a great job most of the time anyway.
**Movie Mode ***(7.25)*
The A640 has a movie mode available straight from the mode dial, and that is helpful when it is needed on the fly. Like many of its Canon siblings, this PowerShot has good-looking video. It records at television-quality 640 x 480 pixels at a frame rate of 30 per second. That frame rate can be slowed down to 15 per second too. The same frame rates are available at a smaller resolution of 320 x 240 pixels. Photographers can shoot up to an hour or 1 GB at a time. There is also a video mail option that records 160 x 120 pixels at 15 fps for up to three minutes. Previous Canon digital cameras had a "fast frame rate" setting that allowed users to shoot video at 320 x 240 pixels at 60 fps for one minute; however, the A640 does not have this mode. While it was neat to watch the smooth movements in the LCD screen, this mode was still pixilated on the television screen and so it will not be missed much on the A640.
There is a lot of flexibility within the movie mode. Users can select Standard, Compact, Color Swap, and Color Accent movie modes by pushing right and left with the multi-selector. White balance, self-timer, and My Colors settings can be chosen from the Func./Set menu. When the A640 is recording, the optical zoom freezes, but the 4x digital zoom is available. It degrades the image quality, so is not recommended for extensive use. The A640 records monaural audio, and it sounds good for the most part. However, if there is loud noise within close proximity – i.e. ripping Velcro, clapping, singing – while there is also background noise, the recorded audio sounds like it misses a few beats here and there. It does fine recording voices and even sounds, but it goes haywire when the volume changes suddenly. Movies can be played back on the camera normally or in slow motion (with a 5-step adjustment to show just how slow you want it). Movies can also be divided into two clips in the playback mode, so users can delete unwanted footage – or they can save both pieces of the clip. Overall, the Canon PowerShot A640’s movie mode is impressive and offers a lot of features for its price range.
Drive / Burst Mode*(6.0)*
From the Func./Set menu, self-timer and burst modes are available. There is the standard Single mode, of course, followed by the Continuous mode. The latter shoots 1.5 fps which is very slow and can hardly be called a burst mode at all. However, it still has some redeeming qualities. The files are incredibly large (10 megapixels), and the camera can snap pictures to the capacity of the memory card. Surprisingly, the flash isn’t disabled in the burst mode – unless manually disabled. The A640 still shoots with the flash at a decent clip. There are three self-timer modes: 2 and 10-second delays, and a custom self-timer that lets users select a delay of 0-30 seconds with a burst of 1-10 shots at the end. This is handy for group portraits where you want several copies of the same shot just to make sure everyone’s eyes are open.
The playback mode is accessed by a small switch on the back of the camera. The switch has grooves which make it easier to push, but the grooves aren’t deep and are very small. This means to access the playback mode, you might have to sacrifice a fingernail or two. Once there, however, there are plenty of things to do: view, organize, and edit.
Viewing can be done file by file or by index screens with 9 pictures on them at a time via the wide end of the zoom lever. Pushing the zoom lever toward the telephoto side zooms in on individual pictures from 2-10x. Viewing is made simple with the automatic rotation function; this is especially great for slide shows. There is an on-camera button for erasing photos, but if users want to delete more than one at a time they will have to enter the playback menu.
Erasing photos by entering the menu isn’t very streamlined. It’s good if you want to delete all the photos, but if you want to delete only half of them, you’ll get a good thumb workout. Pictures and videos can be shown without file info, with basic file info, with a full set of parameters, and even a histogram (although viewing the histogram and file info shrinks the actual image to about a quarter of the size of the screen). A very basic slide show feature is also available.
Movies can be viewed normally or in 5 levels of slow motion forwards or backwards; this is an interesting and fun feature. Movies can also be primitively edited, or they can be divided into two clips. This makes it easy to get rid of boring or unusable footage.
There are also editing features for still pictures, outlined in the playback menu a few paragraphs above. The My Colors effects can be applied to still pictures but not to movies. The voice memo function records up to 60 seconds of audio with each image.
As far as organization goes, the A640 doesn’t categorize photos the way newer PowerShot cameras do. Still, it has a "jump" feature that lets users move through lots of pictures 10 at a time, 100 at a time, or it can move to the shot date, movies, and folders on the memory card. The "jump" feature is accessible from the top of the multi-selector. The playback mode is an overall success.
Custom Image Presets*(7.5)*
This digital camera has a healthy selection of scene modes. It keeps three of the custom image presets directly on the mode dial: Portrait, Landscape, and Night Scene. The other scenes are grouped together under the "SCN" position on the mode dial: Foliage, Snow, Beach, Fireworks, Underwater, Indoor, Kids & Pets, Night Snapshot, Color Accent, and Color Swap. Users can change between scenes by scrolling right and left on the multi-selector. Most of the Func./Set menu is disabled, but the image size, compression, and self-timer options are still up for grabs. Exposure compensation can also be adjusted from the on-camera button. Many of these scene modes are seen on other cameras, but the Color Swap and Color Accent presets are unique to Canon PowerShot digital cameras made in 2006 and onward. The Color Swap preset lets users select two colors within the frame to trade. I chose to swap the color of my red couch with the glossy yellow of my son’s toy box. The result was an image of a yellow couch and red toy box – but the couch also had dark red shadows in spots and looked very ugly. Color Swap isn’t the most usable mode, but it is unique and fun to play with. It just shouldn’t be taken seriously. The Color Accent mode highlights one color and dims all else to blacks, whites, and grays. This is cute for accenting lips or the metallic green of your new car.
Manual Control Options
Like many of its A-series siblings, the Canon PowerShot A640 offers a nice range of automatic to manual control. Users can graduate from the scene modes to the program and priority modes, to the fully manual mode. The shutter speed and aperture are changed using the multi-selector and the exposure compensation button. This isn’t the fastest or easiest way of doing things, but there just isn’t room for jog dials galore on the A640’s body. Still, the amount of manual control offered is great for the price of this digital camera.
The Canon PowerShot A640 has a 9-point through-the-lens auto focus system that has three modes: AiAF (default), FlexiZone, and Center. The AiAF system lights up green boxes around various areas of the frame to show where the camera is focused. The Center option is fixed to the middle, of course. The FlexiZone AF mode is very interesting. It allows users to manually move the focus point all around the frame with the multi-selector. The auto focus system works quickly and effectively, something that can’t be said of all compact digital cameras. It does focus much better and faster at the widest focal length over the telephoto end. The A640 normally focuses from 1.5 ft to infinity, but it has a macro mode that shortens that range. The macro mode is accessible from the bottom of the multi-selector and can focus as close as 0.39 inches in wide and 9.8 inches in telephoto. The A640’d auto focus system performed decently in low light, although it did take more time. The camera is equipped with a small, orange auto focus assist lamp to illuminate subjects that are dimly lit.
The bottom of the multi-selector accesses the manual focus mode in addition to the macro mode. Users can scroll right and left with the multi-selector to change the focus; as they do so, a scale shows up with distances on it. In the recording menu, users can choose whether to activate a zooming function in the manual focus mode. It enlarges the center of the image so it’s easier to see. This function isn’t complimented by the LCD screen’s resolution though. With only 115,000 pixels on the 2.5-inch screen, it is hard to focus on detailed subjects.
Newer PowerShots are equipped with a Digic III processor that allows for even greater sensitivity, but the A640 still has a decent range from 80-800. This model also has automatic and High ISO Auto settings; the latter is for low light photography. All of the options are located in the Func./Set menu with a live view when scrolled through. This is a nice setup, and it helps users choose the best setting for the exposure.
While the available options were sufficient, the A640's noise levels were unacceptably high. To view a more elaborate report on the A640's noise levels and image quality, refer to the testing/performance section of the review.
Also located in the convenience Func./Set menu are the Auto, Daylight, Cloudy, Tungsten, Fluorescent, Fluorescent H, Underwater, and Custom white balance settings, also with a live view. These proved to be fairly accurate, with the Custom option trumping them all as usual. It is simple to set, and that is imperative for the target audience of this camera. There is a small bracket in the center of the frame where the white balance is measured, so rather than filling a room with white, users need only to frame something white in the tiny bracket. An on-screen prompt alerts users to push the Menu button when the white subject is framed.
There are 21 exposure modes on the Canon A640 ranging from automatic to manual. Many of the scene modes allow users to adjust the exposure compensation though. +/- 2 EV is available in steps of 1/3 via the designated exposure compensation button. There is a live view along with the exposure compensation scale that is shown at the bottom right corner of the screen.
There are live views of the three metering modes in the Func./Set menu: Evaluative, Center-weighted Average, and Spot. The first is the camera’s default, and works well in average lighting but is fooled by backlit subjects. For those situations, the other two modes work well. For pictures when the subject is off-center and the lighting a bit strange, the Spot mode works well. Its tiny metering point can be manually moved along with the FlexiZone AF point. This grants more flexibility to users of the Canon A640.
**Shutter Speed ***(7.0)*
The A640 offers a wide shutter speed range for a compact digital camera: 15-1/2500th of a second. The camera automatically chooses the shutter speed unless in the Manual or Shutter Speed Priority (Tv on the dial) modes. There is no live view when changing shutter speeds in the priority mode, but there is one in the manual mode – which is helpful. When the aperture is open to its brightest f/2.8 in the manual mode, the shutter speed is limited to 1/1250th of a second. This shouldn’t hinder any photographic opportunities.
The A640 has a 4x optical zoom lens with maximum apertures of f/2.8 at wide and f/4.1 at telephoto. The f/2.8 aperture is standard now on lenses, but the f/4.1 is at least a full stop brighter than what competing cameras offer. Throughout the lens range, f/8 is as small as the aperture goes; this is also common on compact digital cameras. Once again, there is a live view when switching apertures in the manual mode but not in the priority mode. Here are the choices at the widest focal length: f/2.8, f/3.2, f/3.5, f/4.0, f/4.5, f/5.0, f/5.6, f/6.3, f/7.1, and f/8.0. At telephoto, the only addition is the maximum f/4.1 setting with those above it still available.
Picture Quality / Size Options*(7.5)*
The 10-megapixel Canon PowerShot A640 offers a few image sizes in the Func./Set menu: 3648 x 2736, 3648 x 2048 (widescreen), 2816 x 2112, 2272 x 1704, 1600 x 1200, and 640 x 480. These JPEG images can be compressed to Normal, Fine, or SuperFine files. At the top resolution and compression, an image file measures about 3.4 MB. This won’t leave a lot of room on a small memory card. In fact, it’s enough for only 9 pictures on the included 32 MB MMC card. Of note is that there are no image sizes optimized for 4 x 6-inch prints. Canon tried to skirt this issue by providing 3:2 guide lines that can be activated in the recording menu. However, users who want perfectly cropped 4 x 6-inch prints won’t have any way to print directly from the camera; they will have to upload the photos to a software program for cropping before printing.
Picture Effects Mode*(8.5)*
This PowerShot is loaded with picture effects, due mainly to the built-in My Colors mode. Available from the recording and playback modes, My Colors provides the following options: Vivid, Vivid Blue, Vivid Green, Vivid Red, Neutral, Sepia, Black & White, Positive Film, Lighter Skin Tone, Darker Skin Tone, and Custom Color. There is a live view that shows the effects of each when scrolled through in the Func./Set menu, although the titles of the effects are intuitive. Users can customize color with +/- 2 adjustments in full steps on the following parameters: Contrast, Sharpness, Saturation, Red, Green, Blue, and Skin Tone. Movies can be tinted all these colors before recording, but it cannot be changed in the playback mode. Overall, these effects aren’t replacements for Photoshop but are fun to play with and are easy to use.
Connectivity / Extras
*The Canon PowerShot A640 comes with a CD-ROM that has version 29.0 of Canon’s Solution Disk. It includes ZoomBrowser EX, PhotoStitch, and an EOS Utility window. The ZoomBrowser EX program offers basic organizational and editing functions, and PhotoStitch connects all the pictures from the camera’s Stitch Assist mode. The EOS Utility program allows users to do everything from control the camera remotely to uploading customized shutter sounds and startup images. This is fairly elaborate software for a compact digital camera.
*Jacks, ports, plugs*(5.0)*
On the right side of the camera is a stiff rubber door. Beneath it are three separate jacks for USB, AV output, and DC input. The USB 2.0 hi-speed mini-B jack connects the camera to printers, computers, and other USB-enabled devices. The AV jack outputs mono audio in NTSC or PAL format for television slide shows and movie viewing.
Direct Print Options (7.0)
The Canon PowerShot A640 connects to all PictBridge compatible printers with its USB cable, but Canon roots for the Canon CP and Selphy printers, of course. With these branded printers, users can create passport-sized photos and "movie prints." Print orders can be created in a sub-menu of the playback menu.
Once orders are created and the camera is connected to a printer, users need only to push the Print/Share button with the LED in the center to transfer the order.
The camera is a decent weight on its own, but the batteries add quite a bit of heft. The A640 accepts 4 AA batteries which are convenient to find in drug stores but aren’t nearly as light as most lithium-ion batteries. The alkaline AA batteries last for 280 shots, and that is decent compared to most other AA-powered cameras. With rechargeable Ni-MH batteries, the camera can get up to 500 shots per charge (these stats are with the LCD screen on the whole time). The batteries are crammed under a door with a lock; when it opens, it springs open so users will have to beware of falling batteries.
The Canon PowerShot A640 accepts SD, SDHC, and MMC media. The camera does not have internal memory, but it comes with a 32 MB MMC card. The card is loaded next to the batteries in the compartment below the hand grip. Consumers who purchase the camera will definitely need more memory than what is provided in the package. 32 MB is only enough for 9 pictures at full resolution, so users who also want video will have to splurge on more memory.
Stitch Assist – With its very own position on the mode dial, the Stitch Assist lets users choose whether to shoot right to left or left to right with the exposure compensation button. When the button is pushed twice, users can tweak the exposure compensation on its regular +/- 2 scale. The live preview shrinks significantly when shooting in this mode, but it does provide an overlay so users can line up the last shot with the next shot. The camera’s Stitch Assist mode doesn’t limit how many photos can be snapped in succession, and the camera doesn’t actually stitch them up together. It is just what it says it is: an "assist." The pictures must be loaded to a computer with the included PhotoStitch software and attached that way.
*Tethered Shooting – *Using the Canon A640, the included software, and the included USB cable, users can sit at their computers and snap pictures remotely with the camera. This doesn’t exactly work as a web cam. But still shots can be taken, as long as the camera is in the recording mode. Otherwise, the camera will transfer pictures to the computer in the playback mode.
Canon PowerShot A630 – This digital camera was released alongside the A640 and replaces the A610. The Canon PowerShot A630 has 8 megapixels and comes with all the same modes and options as the A640. They are so similar that the user manuals are the same, with only a few notes here and there on where they differ. There are a few minor adjustments to the specs including a slightly faster burst mode, better battery life, and shorter digital tele-converter on the Canon A630. Indeed, this camera snaps 1.8 fps rather than the A640’s 1.5 fps. The alkaline AA batteries last longer at 350 shots over the A640’s 280-shot lifetime. The Canon PowerShot A630 has a digital tele-converter function, but it reaches 2x instead of the A640’s 2.3x. One of the bigger differences that will perhaps go unnoticed by most point-and-shooters is that the A630 cannot shoot remotely by a computer like the A640. Both PowerShot digital cameras have the same 2.5-inch LCD, 4x lens, and flash components. The A630 can be found online easily for about $250.
Casio Exilim EX-Z1000 – This 10.1-megapixel camera is Casio’s version of the high-resolution pocket cam. It produces unrealistic colors, poor quality in low light, and disappointing detail in resolution testing. It does not have manual exposure control like the Canon, but it allows a few adjustments in its auto mode. Even those adjustments aren’t much though; for instance, the maximum manual ISO setting is 400. Like many of its Casio relatives, the Exilim EX-Z1000 has a vast number of Best Shot scene modes,38 to be exact. The 0.9-inch thick digital camera has a shorter 3x optical zoom lens and a wider 2.8-inch LCD screen with much better resolution of 230,000 pixels. It can be found online for less than $300.
Panasonic Lumix DMC-LX2 – This compact digital camera has 10 megapixels, but they come on a 1/6.5-inch 16:9-formatted image sensor. The LX2 has its luxuries and problems. It has a 2.8-inch LCD screen with 210,000 pixels that still falls short of the standard but beats the Canon A640’s screen any day. This digital camera has similar modes ranging from scenes and automatic to priority and manual. It has a movie mode that records 1280 x 720-pixel resolution at 15 fps, and it has smaller resolutions at better frame rates. Complimenting the movie mode is the optical image stabilization that keeps movies smooth and pictures free of blur. Other manual controls include exposure compensation, ISO to 3200, and white balance with custom and fine-tuning settings. The Panasonic LX2 has a rickety built-in flash and some serious shutter lag issues. Its burst mode is fast at 3 fps, but it maxes out its buffer on the third frame. The Panasonic Lumix LX2 sells for a retail of $399.
Who It’s For
Point-and-Shooters – This digital camera is created with these consumers in mind. The Canon A640 is easy to use, has an interesting and large LCD screen, and takes decent pictures.
Budget Consumers – The Canon PowerShot A640 is one of the most expensive in its lineup because of its massive 10-megapixel image sensor. Sure, the A640 is cheaper than the 10-megapixel Canon Rebel XTi, but budget consumers looking for a compact camera with lots of resolution can still find cheaper options.
Gadget Freaks – The resolution on the image sensor may sound appealing, but there really isn’t much to entice the gadget freak otherwise.
Manual Control Freaks – These consumers will appreciate the variety of levels of control with the auto, priority, and manual modes. Users can customize everything from the flash power to the white balance and contrast. The traditional exposure control of shutter speed and aperture is available too.
Pros/ Serious Hobbyists – The Canon A640 has plenty of resolution, but it couldn’t satisfy a professional. Serious hobbyists might get into this model with its manual modes and options, conversion lenses, and slave flash.
The Canon PowerShot A640 has its own niche in the market that may make it priceless to some consumers. It is the only 10-megapixel compact digital camera that has manual control over shutter speed and aperture. There are a few other compact 10-megapixel cameras, but their manual controls are lacking. Consumers who are dead set on owning 10 megapixels with manual control will have to fork over the $399 retail or $350 street price. Consumers who are looking for a compact digital camera that has plenty of resolution and manual controls will probably want to look at other models though. The Canon PowerShot A630, for instance, comes with all the same modes and features as the A640, but it has 8 megapixels instead of 10. It also costs significantly less at about $250 online.
The PowerShot A640 has more pros than cons. It has a lot of resolution at 10 megapixels, but that won’t be necessary for most users of this camera. Point-and-shooters won’t need to create life-size prints since most will make small prints with an occasional enlargement. Believe it or not, the resolution isn’t what makes the A640 great; in fact, the resolution significantly hurts the camera's performance.
What makes the A640 a solid camera is that it allows beginners to develop their photography skills by graduating from the scene modes to the manual mode without needing to buy different cameras. A few of the A640’s highlights include a rotating 2.5-inch LCD screen that has a wide view, a built-in flash with adjustable power, easy to use control and mode dial interface, and in-camera editing for simple direct printing. The Canon A640 is a bit pricey with its $399 retail. Bargain hunters can go for its PowerShot companion, the A630, though. It has 8 megapixels with the same modes and many of the same features – for about fifty to a hundred dollars less. Considering that most point-and-shooters won’t create huge prints, the A630 may be a better buy. The Canon PowerShot A640 is still a good digital camera though – if you’ve got the cash.
Specs / Ratings