Previous page Next page

ISO Accuracy

The actual sensitivity of each indicated ISO is measured using the same shots as are used to measure ISO noise levels, we simply compare the exposure for each shot to the metered light level (using a calibrated Sekonic L-358), middle gray matched. We estimate the accuracy of these results to be +/- 1/6 EV (the margin of error given in the ISO specifications). Note that these tests are based on the sRGB JPEG output of the cameras, in accordance with ISO 12232:2006, the standard used by camera manufacturers.

By our tests, the G1 X's measured sensitivities are about 1/3 stop lower than indicated across the ISO range (i.e. images are fractionally darker than expected for any given set of exposure values). A discrepancy this small has little practical impact in real world use.

Noise and Noise Reduction (JPEG)

Note: this page features our interactive noise comparison widget. By default, we show you the default noise reduction settings of the camera tested, and three other models of the same class. You can select from all available NR options, and from other cameras. The 'tricolor' patches beneath the familiar gray/black/portrait images are taken from the same test chart, and show how noise impacts upon blue, green and red areas of a scene.

ISO range noise comparison

At its default 'Standard' noise reduction setting, across the ISO range, the Canon G1 X captures JPEG images that show a remarkably good mix of noise reduction and detail retention. Up to ISO 1600 you pretty much don't need to worry about noise, with only some smearing of fine low-contrast details but very good overall and high-contrast detail.

At ISO 3200 and higher the loss of fine detail is starting to become more obvious, albeit initially only at a 100% magnification. Chroma noise is remarkably well under control but makes a first visible appearance at ISO 6400, when you can spot purple traces in plain-colored areas. That said, these traces pretty much disappear if you reduce the viewing size to the dimensions of a 24 inch screen, so there is no need to worry if you don't print or otherwise output very large formats.

Chroma noise gets more intrusive at the very highest ISO setting, occasionally in a banding pattern, but again even these highest ISO images retain good saturation and high-contrast detail and are therefore perfectly usable at smaller output sizes or for web display.

All in all the PowerShot G1 X yields better high-ISO results, with more detail and more pleasant rendering of noise, than the current line of APS-C Canon DSLRs, such as the EOS 7D or 600D. The fact that the raw output of these cameras is near identical this can be attributed to improvements in the JPEG engine.

The G1 X gives you some control over high-ISO noise reduction - you switch from 'Standard' to either "Low' or 'High' - but unfortunately you loose this control as soon as you switch to raw or raw+JPEG shooting. In those modes noise reduction is fixed at the 'Standard' setting.

Raw noise (ACR 6.7 Beta noise reduction set to zero)

As we've seen above the G1 X's JPEG output is very good in terms of both measured noise and retention of detail. That is only partly due to the Digic 5 processor's JPEG engine doing a very good job. In addition the camera performs very well at the sensor and raw capture level. Both chroma and luminance noise levels are low for this class of camera and roughly in line with the enthusiast DSLR Canon EOS 7D, the sensor of which is closely-related to the G1 X's.

Previous page Next page
Our favorite products. Free 2 day shipping.
Support this site, buy from dpreview GearShop.
Canon PowerShot G1 X


Total comments: 9
By rugosa (2 months ago)

I bought a G1X 2 weeks ago from a person that bought it for his wife for Christmas. She found it too much camera for her needs and so I bought it with about 10 shots total for $400. I usually shoot with a Nikon D300 and the Nikon higher priced lenses. For underwater and a light carry around I had a G10 for 5 years. After 2 weeks of shooting I must say that I'm amazed by the IQ of the photos this camera puts out. Low light shots up to ISO 1600 are allot better than my D300. It's not a perfect camera but then non of them are. Ordered a Canon 500D close up lens for it after seeing how well that worked on Marco Nero's photos with the G1X on . This camera also shoots some very good underwater photos from examples I have seen on the internet so I picked up Canon's case on sale for my trips south. All told I think that although this camera is not for everyone most owners give it at least an 8/10. has another good review, great landscape photos

Comment edited 51 seconds after posting
By Gunzorro (2 months ago)

I've been wanting this camera since it was announced. I'm primarily a DSLR shooter, and FF at that. I also have owned a G6 and currently G10 and S110. So, I'm pretty familiar with where this camera fits in and what a step it is for Canon to take.
I just bought a used version at a very nice price so will be trying it out in the near future.
I would have rated the camera a little higher, based on my past experience with Canon and reports I've read from reviews and owners. Particularly, Optics and Performance would have got a couple ticks up in my estimation. I think a 79 or 80 would have been appropriate -- being practically in a category of its own: attached zoom, large sensor, compact camera.
It won't be a camera for everyone, true. But if you want better IQ than P&S and use it as a second camera to your DSLR for quick grab shots and take-anywhere convenience, you should be well served! :)

jan snks
By jan snks (5 months ago)

Image quality G1X, dpreview reports "excellent image quality across the ISO range without nasty surprises".
I would like to refer to the review of this camera. They reported a nasty Light Leakage phenomenon at higher ISO settings and short shutter times. This defect seems to be confirmed by Canon.
Would anybody comment on this ?

By millhoud (6 months ago)

I've noticed that the g1x took this studio shot at f7.1 , while other "enthusiast" compacts (g15 or p7700...) at f4.5. Could somebody explain me why's that? It would be nice to know the shutter speed too. Thanks

Richard Butler
By Richard Butler (6 months ago)

It's to offer enough depth-of-field (it's a 3D target).

This has a sensor much bigger than the others, so needs to be stopped-down further in order to provide enough depth-of-field.

By millhoud (6 months ago)

Please sorry my ignorance, but to achieve this it has to use a slower shutter speed too or, thanks to the higher light-catching capabilities of the bigger sensor the g1x uses comparable shutter speeds as, say, the g15 or p7700 , with a smaller aperture?

By lem12 (7 months ago)

If Canon increases DR able to at least match T2i and updates its Panorama mode (similar to the Sony's would be great), this would be true compact I'm looking for. I'll buy it no doubts!

By Wildbegonia (7 months ago)

Almost but not there yet.

By Ponderer (8 months ago)

G1x Cannons almost camera
Almost an APS-C sensor, Almost a good EVF, Almost enough lens magnification, Almost small enough. A good first try for a company that just started designing cameras.

Total comments: 9