Canon PowerShot G1 X Mark III review

Canon has somehow shoehorned an APS-C-sized sensor into its flagship compact camera, but it’s come at a cost

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Apart from the sluggish zoom action, the PowerShot G1 X Mark III feels pretty responsive. You start it up by pressing a small power button on the top, and the camera has to extend the lens to get ready for shooting. So, the startup isn't instant, but it's pretty quick.

The autofocus is snappy too, as we've come to expect from Canon's Dual Pixel CMOS on-chip phase-detection AF technology. It does slow down and become a little less reliable in dimmer conditions, such as domestic household lighting, but in most conditions it's very good.

The tiny battery is a worry, though. One on trip out it was flashing red an hour or so after leaving the house (from a full charge), though on another it was fine. Even so, with a modest 200-shot capacity, you'd want to make sure it had a full top-up before any outing. It does support USB charging too, so you could always take a smartphone powerbank and the charging cable as a backup.

The camera has captured the warmth of this late afternoon sun beautifully, and apart from a little negative exposure compensation, it needed no manual intervention

The camera has captured the warmth of this late afternoon sun beautifully, and apart from a little negative exposure compensation, it needed no manual intervention

The big sensor may have forced some compromises in the lens specifications, but the payback is really excellent image quality. The lens may have been crammed into a tiny space, but it delivers real edge to edge sharpness and across the full zoom range. 

This was taken at the minimum focal length of 15mm

This was taken at the minimum focal length of 15mm

And this was taken at 45mm, the maximum zoom setting. The 3x zoom range is pretty modest and the lens drops two f-stops in aperture across the range, too

And this was taken at 45mm, the maximum zoom setting. The 3x zoom range is pretty modest and the lens drops two f-stops in aperture across the range, too

Canon's 24-megapixel APS-C sensor, meanwhile, delivers rich colours, strong contrast, and good dynamic range. With compact cameras you usually get small sensors so you need to be wary of pushing the ISO too high  but here, you have no such worries. Image detail starts to soften up by ISO 6400 as you'd expect, but up until that point, image quality stays much higher than you'd expect from a pocket-sized camera.

Incidentally, Raw shooters using Adobe Lightroom or Camera Raw programs should note that the default noise reduction (or lack of it) in these programs does not do Canon Raw files any favours. JPEGs straight from the camera are much cleaner than the Raw versions appear in the Adobe software, so don't judge the camera's noise levels on this alone!

This colourful graffiti really popped here, with -1EV exposure compensation to make the shadows go to a solid black

This colourful graffiti really popped here, with -1EV exposure compensation to make the shadows go to a solid black

The dynamic range is pretty good. This is a JPEG straight from the camera, and the Raw files have just a little extra highlight and shadow detail

The dynamic range is pretty good. This is a JPEG straight from the camera, and the Raw files have just a little extra highlight and shadow detail

Exposures made using the default Evaluative metering system were pretty much spot on too. This can be a bit wayward on some consumer Canon EOS DSLRs, where the exposure is linked heavily to the active autofocus point and can produce overexposure and erratic results, but there were no such problems here. All our test shots used the Auto white balance, and we didn't feel the need to tweak the colour balance in any of them.

You have to be more careful with focusing than with the average compact because the depth of field is more shallow.

You have to be more careful with focusing than with the average compact because the depth of field is more shallow.

There's no apparent lens distortion, either, which is especially surprising in such a compact lens. Normally, when you compare Raw files with JPEGs, you can see the effect of any in-camera lens corrections, but ours looked identical. 

This twilight shot was captured at ISO 100

This twilight shot was captured at ISO 100

And this version was taken at ISO 6400. You can see the difference in noise and detail rendition close up, but the colour, contrast and tonal gradations are almost identical

And this version was taken at ISO 6400. You can see the difference in noise and detail rendition close up, but the colour, contrast and tonal gradations are almost identical

Overall, while we have some misgivings about this camera's limited aperture range, sluggish zoom and weak battery life, the image quality it produces is excellent. If you got this kind of quality from an enthusiast level DSLR or mirrorless camera you'd be pretty pleased, so to get it from a camera you can slide into a jacket pocket is quite something.