Full Review

The megapixel war is on and what sounded like a dream number a year ago, is now quickly becoming the "standard": 10 million pixels. Digital SLRs have seen a huge increase in popularity lately - partially due to the associated price drops. That makes it harder for high-end point-n-shoot cameras to finde a niche between the upper end point-n-shoots and the low-end SLR. Previously that meant below $1000, but the justification becomes less convincing with SLRs now being available well below that. The new G7 continues the high-end Powershot line for Canon, but is visibly different from the S3 IS. Not only does it sport a more classic body and the now mandatory 10 MPx sensor, the DIGIC III processor is not missing either. Yet, the biggest argument in the G7's favor might be the image stabilized long zoom (6x).


IN A NUTSHELL

The Powershot G7 comes at a surprise since the market segment of high-end point-n-shoot cameras seemed kind of obsolete. Yet it offers more functionality and better ergonomics than a typical compact camera, while keeping it in a smaller package and with more consumer oriented features than a SLR.

The ten megapixels may be a must-have in today's market, but overall features in favor of the G7 certainly are not limited to the sensor alone. A few innovative usability features (i.e. ISO dial) make the flipping through menus unnecessary. Flexibility is good enough for many enthusiasts that don't shy away from spending more money on accessories like an add-on lens or external flash, but still don't want to take the plunge into the SLR pond. Face tracking enables candit shots to turn into sharp portraits. The 6x zoom lens is not the longest in the market, but optical quality is very good despite the slightly "slower" characteristics.

On the negative side, the G7 feels more limiting due to the eliminated RAW recording (cost?) and reduced ergonomics for the sake of style. The small sensor (compared to SLRs) shows its limits in chromatic aberration and overall noise and loss of sharpness under less ideal conditions. Noise reduction algorithms (above 1.3 sec) are sophisticated and generally better than the noise at a higher ISO (400 and up). An example: I found it advisable to reduce ISO in case your exposure time at ISO-800 is near 1 sec. Forcing ISO-400 would enable the NR since exposure is now 2 sec.

Anyway, the Powershot G7 is a great compact camera, but somehow appears to have lost its luster -- despite being new. Main reason for the mixed feelings is the invasion of the low cost SLR which provide better performance at a similar price but of course in a bigger package. Yet on the other end, even more compact cameras than the G7 offer similar quality while loosing out in controls. If you can afford two cameras, I'd suggest the SD800 IS and the EOS 30D. However, if there is only room for one, the Powershot G7 might fit the bill (small in size and reasonable performance).


POWERSHOT G7 vs. SD900

The technical specs of the G7 read a lot like a SD900 with a bigger zoom and added image stabilization. Yet, visually they're actually quite different -- a tribute to the difference in target audience. The black housing of the Powershot G7 provides more room for ergonomics (handle) and controls as well as a hot shoe for an external flash. Yet it manages to stay well below SLR dimensions in size and weight, mostly due to the smaller sensor, battery and the integrated lens. The core of both cameras is virtually identical, with the same 10 MPx (0.556") sensor and same digic III processor as well as the same 2.5" (207,000 px) LCD display and optical viewfinder. Both cameras snap pictures in roughly 2 seconds (neither has a burst mode) and overall functionality regarding automated modes is very similar too. In fact, the price for the G7 is only $100 more than the SD900, and with the purchase of a Pixma printer Canon offers a $100 rebate for the G7.

Differences are more significant for enthusiasts that still hesitate to buy an SLR (i.e. due to size) and still would like a little more control. Starting with the lens, the G7 goes slightly wider with 7.4 mm (vs. 7.7 mm) and significantly longer with 44.4 mm (vs. 23.1 mm). The sensor size translates this into a 35 mm film equivalent of 35 mm - 210 mm (6x). The speed of f/2.8-4.8 is similar to the SD900, but not as impressive as the predecessor (S3 IS). The integrated IS certainly helps out to tame the longer focal length and across the range in low light. It feels similar effective in the "shot only" mode to the SD800 IS, but more relevant due to implications of a longer zoom. The hot shoe in the G7 is useful for a more powerful flash and a better position to reduce red eye. Depending on your flash design, bounce flash may be the most advanced additional feature the hot shoe opens for the user (with an additional $200 - $500 expense)

Overall picture quality is not surprising to be very similar to the SD900, with virtually identical noise (okay at ISO 800, bad at ISO 1600) and good quality in bright light. Situation dependent differences stem from the IS which is only existent in the G7 as well as the longer focal length (wider zoom) as well as the ability to control shooting parameters more closely (in case the program doesn't succeed). The G7 is clearly more versatile than the SD900, but at the cost of portability (pockets need to be larger) and overall slightly more complicated use (if manual is desired). Yet, in at least one example the G7 is even easier to use since it sports a direct ISO dial to quickly set the speed without having to hassle through menus.


DETAILS

Body: [****-] - The G7's retro style is in line with the current trend and easy to the eye. With edges a little sharper than the S3 IS, handling is affected by the slightly smaller grip. Compared to an SD900, the G7 is much easier to hold and operate with one hand. Yet, ergonomics suffered compared to the S3 due to the small grip and the trigger button location. (Retro isn't always better.) The G7 weighs a significant 140 g less than the S3. The smaller grip and lower weight are a direct result of the smaller battery. Good as it may seem, it also means that battery performance could have been better (with the previous larger battery which is almost 2x the capacity).

Lens: [*****] - The zoom lens ranges from 7.4mm to 44.4 mm with a maximum aperture of f/2.8 (wide) - 4.8 (tele). Equipped with Image Stabilization, the 6x zoom lens doesn't go as wide as the SD800 IS, but significantly longer than both SD800 and SD900. The 0.556" sensor translates the zoom range into a film equivalent of 35mm - 210 mm, or versatile enough for most uses. The maximum aperture of 4.8 at 210 mm is "fast" enough to allow for some good portrait shots with a pleasing background blur, though the bokeh isn't the most appealing (round) I've ever seen. The S3 lens showed slightly better performance with f2.0-f3.0, though the zoom only reached to a film equivalent of 35mm - 140mm and really doesn't compare apples to apples. The G7 allows the use of proprietary add-on lenses (i.e. macro).

Flash: [****-] - Integrated typically means limited. This is mostly due to its close position to the optical axis (red eye, no bounce), but for party pictures greatly limited by the standard E-TTL (without distance readout and adjustable flash power). Rated up to 4 m, limitations may justify an external flash. Otherwise, it does the typical preflash to reduce the pupil size to reduce red eye. The Auto ISO mode is the only adjustment the G7 provides to react to different flash density based on object reflectivity and distance. SLRs show similar limitations and external flash is simply going to provide better light. (Some modern SLR cameras like the EOS Digital Rebel XTi actually provide E-TTL II capability even for the internal flash.) The white balance for flash exposure is tuned towards a slightly warmer tone which makes for more pleasing portraits, but needs to be considered when shooting neutral objects.

Display: [****-] - The 2.5" screen is used in many cameras and identical to the SD800 IS or SD900. Hence, performance is very similar in normal daylight (good), indoors (excellent) and direct sunlight (poor). At least for the latter case, the S3's LCD status display is much easier to read! Nevertheless, both viewing angle and resolution (207,000 pixels) are very good. The anti-glare coating is very effective. As usual, an optional cover is highly recommended. Unlike the S3 IS, the G7's display cannot swivel out to accommodate odd posture -- or provide cover when retracted.

Functions: [****-] - Geared towards more control in a point-n-shoot format, the G7 obviously provides greater control and the buttons in return improved access. For instance the ISO dial and a programmable button as well as the photo mode dial make for quick access while a camera like the SD900 or SD800 IS would have you navigate through the menu to achieve the same. Naturally, that improves setting speed greatly and allows to focus more on the picture. Relative to the processor, the G7 of course sports face tracking as well as a stitching assistant. Unfortunately the RAW format as used in the S3 and typically SLRs cannot be found in the G7. This may be a tribute to the picture processing that happens in the digic III chip.

Sensor: [****-] - Aside from the question whether 10 MPx really make sense in such a small package, the 0.556" sensor holds a total of 10.4 MPx out of which 10.0 are recorded in the picture. With this being the same sensor that ultimately feeds the same processor as in the SD900, differences are as expected: none. As for any other Bayer sensor configuration, chromatic aberration can be observed at extreme contrasts only. Smaller sensors and the associated wider angle sign responsible for the visibly worse aberration compared to an SLR. Further, the needed interpolation is one of the causes why a Bayer sensor feels "softer" than a Foveon -- a rare breed.

Quality: [****-] - Given that technical parameters are the same, the only visual difference between the G7 and the SD900 is in the lens properties. The G7 allows to stick with the optical zoom where the SD900 only offers up-scaling via digital zoom. Since this is nothing other than a simulated picture out of a much lower resolution, the digital zoom might as well be avoided and left to Photoshop (or PhotoPaint etc.) Given there is enough light, the picture quality is actually quite good and even better with a tripod at the longest zoom setting (despite IS). The Auto sensitivity keeps the ISO sensitivity between 80 and 400, or in manageable ranges. The digic III provides sophisticated noise reduction algorithms over 1.3 seconds, which reduce the resolution slightly via blurring noisy pixels. Yet especially at ISO 1600 the noise is basically unacceptable. Knowing its limitations, the G7 reduces resolution drastically for ISO 3200 by averaging a number of pixels to tame the noise. (Sometimes better than no picture at all)

Speed: [***--] - As with most cameras with an integrated zoom, the start-up speed consists to a large degree of the lens extension. It takes the G7 about 1.4 sec. to be ready (power up). Auto Focus is by no means instant but good for the class with roughly 0.4 - 0.6 sec. Once in focus, the G7 has a minimal delay from pressing the button to actually taking the picture (0.12 sec of "shutter lag"). Not fast enough for action shots, but good for everything else. The G7 also offers to turn the display off and use the freed-up computing power for a much better shutter lag of roughly 0.05 seconds. (Highly recommended for action shots, though less convenient.) The exposure time ranges from 15 sec to 1/2000 sec. Noise reduction is automatically used when using exposures over 1.3 seconds -- a much needed feature. The G7 is capable of capturing two pictures every second.(The difference to the SD900 appears to be more of marketing reasons than technical ones since in practical terms both are identical.)

© 2006, theuerkorn