When its specification was released it surprised a lot of people, because in many ways it is a 
step backwards from the specification of the G6. That excellent f/2.0-3.0 lens has been replaced with a slower f/2.8-4.8 6x zoom, the 2in flip & twist monitor is replaced with a fixed 2.5in screen, and the RAW mode recording, crucial for top-quality professional results, has been lost altogether. Inevitably the 1/1.8in sensor has been upgraded to 10-megapixels, and it features image stabilisation and face-detection technology. Instead of a semi-pro enthusiast’s camera, it seems that Canon has decided to turn the G7 into something closer to the top end of its mid-range A-series compacts.
This is also reflected in the price. The G series has always been expensive, and in fact you can still pick up a brand new G6 for between £350 and £500, but the G7 has a recommended retail price of £449, and is widely available online for as little as £307. For comparison, the series-topping PowerShot A640 (10MP, 4x zoom, 2.5in LCD) is priced at around £220. Has Canon squandered the reputation of the G-series in an effort to appeal to a wider range of consumers?
Perhaps not, because the G7 still has a lot to offer the serious photographer. It retains the rangefinder-like styling of its predecessors, even more so than the G6 since it lacks that camera’s large rubberised handgrip. Build quality is well up to the usual standard with a solidly made mostly metal body, metal-hinged sprung hatches and chunky solidly mounted controls.
It is a surprisingly compact camera considering its specification, not exactly pocket-sized, but not obtrusively bulky. Unlike the G6 the lens has an automatic cover and retracts almost flush with the body, or at least as far as the removable bezel that hides the bayonet fitting for attaching accessory lenses. TrustedReviews - Canon PowerShot G7