Canon G1XMk3 High ISO noise is high.

The G1X3 can be used effectively for documentary work indoors provided one keeps to the wide end of the zoom where f2.8 is available and the location is reasonably well lit.

I recently compared high ISO noise levels in my Canon G1X3 with a Panasonic G85 Micro Four Thirds (M43) camera.

Somewhat to my surprise I found that at around ISO 6400 the G85 Raw files had about 0.3 stops (EV steps) less noise than those from the G1X3.

The G1X3 is described by most reviewers as utilising the same 27mm diagonal Canon APS-C sensor with dual pixel autofocus (DPAF) as several recent models including the EOS 80D, EOS M5 and M6 and others.

If we look at  Raw file data published by DXO Mark (www.dxomark.com) we can see that cameras using the 16Mpx  M43 sensor, including the G85 have a DXO Mark “Sports” (meaning high ISO) score of around 650, while cameras using the Canon sensor score around 1300, which is equivalent to one stop or one EV step higher (higher is better on this scale).

I generally find that there is about a one EV step difference in high ISO noise levels between “one inch” (15.9mm), M43 (21.5mm), APS-C (27-28mm) and so-called “full frame” (43mm diagonal) sensors with newer versions scoring a bit better than older versions at each size.

So DXO Mark’s results for the Canon EOS80D, EOS M5, M6 and similar models are in line with expectations.

DXO Mark has not yet published its results for the G1X3 as of 15 April 2018.

I looked at Digital Photography Review’s Raw Studio Scene results comparing the G1X3, G85, EOS M5 and EOS M6 and Sony A6500. I found that the appearance of digital noise (luminance and color)  in the ISO range 3200, 6400 and 12800 was in line with DXO Mark’s numeric results.

I also found that RAW noise  levels from the G1X3 were in line with my findings.  The EOS M5 and M6 had about one stop less noise at high ISO settings than the G85 but the G1X3 had a bit more noise than the G85, which I estimate at about 0.3 EV steps.

Strangely, the DPR review narrative comments on G1X3 JPG noise levels but not Raw noise levels. 

The G1X3 high ISO JPGs do have low noise but the penalty for that is a marked loss of sharpness which is easily seen on the DPR Studio Scene.

Summary  It appears Canon has Done Something to their 27mm DPAF sensor in the G1X3 to downgrade its high ISO noise performance.

I cannot recall seeing any narrative reference to this in a published review of the G1X3 although as Jesse Stone might say,  “the information  is out there, you only have to let it in”.

This will not be welcome news for buyers contemplating purchase of a G1X3 which has already attracted some negative comment (from myself and others) about the modest (f2.8-5.6) aperture range of the lens.

Several cameras which use the “one inch” (15.9mm diagonal) sensor would appear to be more suitable for indoor, low light work including any of the Sony RX100 models, the Panasonic LX100 and even Canon’s own G5X. Each of these models has a much wider lens aperture across the zoom range than the G1X3.

I am still happy to recommend the G1X3 for its compact size, very reliable, accurate autofocus, excellent lens and very good image quality in the low to mid range of the ISO scale.