This is an area of the market that's seen some exciting changes recently. In the past, a high-end compact camera would have a slightly larger sensor than a regular point-and-shoot model – for example, a 1/1.7-inch sensor rather than the usual 1/2.3-inch – and this would give a modest and useful boost to the image quality.
You would also get a better quality lens, manual control, the ability to shoot raw files and a higher grade of finish and construction.
Canon PowerShot S120 and S200
Canon's two smallest high-end compacts fit into this category. The S120 is highly regarded for its size and power, using a control ring around the lens for many common adjustments. It comes with a 12-megapixel sensor and a 5x zoom with a minimum focal length of 24mm equivalent and an f/1.8-5.7 maximum aperture.
The S200 is a slightly cheaper version, with a 10-megapixel sensor and 24-120mm f/2.0-5.9 lens. The ISO range is slightly reduced and the screen on the back has a lower resolution.
If you find these cameras are too small, the PowerShot G16 could be the answer.
Canon PowerShot G16
The G16 is the last of Canon's 'old-school' high-end compacts. It has a 1/1.7-inch sensor, like the smaller S120 and S200 models, but in a larger body, with more external controls, an optical direct vision viewfinder and a 5x 28-140mm equivalent lens.
The zoom range might sound similar to the S120 and S200, but the maximum aperture is much wider at longer focal lengths. The smaller PowerShots can only manage f/5.7 and f/5.9 at full zoom, but the G16 lens offers f/1.8 at its shortest focal length, but only drops to f/2.8 at full zoom.
The issue with the G16 is that it still uses a relatively small 1/1.7-inch sensor, where rival makers are moving towards larger sensors in their high-end compact cameras. This is why the next two Canon PowerShots are so interesting.
Canon PowerShot G7 X
The G7 X is smaller and simpler than the G16 (it's hardly larger than the S120 and S200), but it has a much larger 20.2-megapixel 1-inch sensor – almost four times the size of the G16's. Larger sensors usually mean larger lenses, so it's all the more impressive that Canon has managed to match (more or less) the zoom range of the G16 with a 24-100mm f/1.8-2.8 lens.
The G7 X doesn't have a viewfinder, nor any means of attaching one, but that's design compromise in order to produce such a small camera.
It does, however, have a flip-up touch-screen display, built-in Wi-Fi and a full HD movie mode which allows full manual control over shutter speed, lens aperture and ISO, together with frame rates up to 60p.
Canon PowerShot G1 X Mark II
The G1 X Mark II has a larger sensor still – a 1.5-inch device somewhere between the 1-inch sensor of the G7 X and the APS-C sensors in Canon's DSLRs in size.
The original G1 X followed the same, rather bulky design of the G16, but the Mark II version is slimmer and neater although – controversially – Canon has dropped the optical viewfinder (though you can clip on an optional EVF unit).
The G1 X Mark II has a 12.8-megapixel sensor designed more with overall image quality and low light performance in mind than outright resolution, and a 24-120mm equivalent f/2.0-3.9 zoom lens.
It does have a larger sensor than the G7 X, but the lens is not as fast at long zoom settings and the outright resolution (megapixels) is lower.
If these cameras still don't offer the kind of image quality, control and versatility you're looking for, then the next logical step is Canon's range of digital SLRs.