Canon PowerShot G7 X Review and Test

Dec 17, 2014--The PowerShot G7 X is Canon's newest compact camera with a 20MP BSI CMOS sensor and an aspect ratio of 3:2. It incorporates Canon's newest image processor--DIGIC 6—that provides fast image recording and high-speed continuous mode. This is the same processor found in the company’s 7D Mark II, albeit in a dual version in the DSLR.

The Canon PowerShot G7 X is a compact camera with a high-speed zoom lens. The unit contains a large 20MP CMOS sensor and a DIGIC 6 processor. A multifunctional lens ring and additional setup dials make handling easy.

The camera has an integral high-speed 4.1X 24-100mm zoom lens (35mm film equivalent). The variable aperture still retains a high-speed character with the change from wide to tele, being just f/1.8 to f/2.8, which is quite unusual for compact cameras. In combination with the large sensor (for a compact camera) it allows users to easily create images with a shallow depth of field.

The camera has a pop-up flash, but an accessory shoe for external flash is missing. The camera offers Wi-Fi and NFC functions. The interfaces are located on the right hand side of the body.

By pressing the “RING FUNC.” button on the back the photographer can set up the function of the lens ring. In standard automatic mode (STD) this ring is used to change ISO speed settings, but of course it can also be used for zooming, manual focusing, white balance settings and more. The ring is located flush with the body and is very slim. A larger ring would be more comfortable.

The Canon G7 X has a mode dial on the top that allows the photographer to choose standard exposure modes and automatic modes. A second dial is used for EV compensation control. A zoom switch helps to change focal length, but the photographer can use the lens ring to zoom as well.

The camera has a 3-inch LCD screen (1,040,000 RGB dots) that is used as control center for menu setup but also as an electronic viewfinder. A dedicated EVF or optical viewfinder is missing. The LCD screen can be flipped upwards (180 degrees) to shoot selfies. In full automatic mode, the camera will switch to the portrait scene mode and changes the lens ring function to focal length. The tilting monitor is handy when taking macro shots near the ground, but a fully articulated LCD with a swivel joint would be more helpful.

The new Canon offers all standard exposure modes: P, TV, AV and M. It has a setup dial on the top which offers an additional “C” mode to save a customer defined setting In addition, the G7 X offers scene modes and a video mode that allows the use of manual exposure settings when recording videos. A second dial, which is located directly beneath the mode dial, allows for EV compensation settings in a  +/- 3 EV range.

The monitor can be flipped upwards by 180 degrees. This can be used for photographing images near the ground or more likely is aimed at the selfie crowd.

The control field on the back allows the user to set up drive mode, flash mode, focusing mode and display settings. It offers a setup dial that encircles the control field and is helpful for menu navigation or image parameter control. The camera has a built-in flash that is activated by a little switch on the left hand side of the body. An accessory shoe is missing, so the G7 X can't use external, add-on flash systems.

Comments on Image Quality

Color: The Canon reproduced the GretagMacbeth chart with a little over-saturation, with red colors especially boosted. This is noticeable in our portrait shot and the test box shot, where red elements seem to “glow.” The skin tone reproduction is good, but the skin tone in our portrait has a visible shift into the magenta area of the color space, which is used, we believe, to optimize or beautify these color areas. In some pictures this effect looks a bit overdone.

The automatic white balance system showed a very good performance. The gray patterns in the test chart are nearly perfectly centered and only the brightest gray and nearly white pattern show shifts into the yellow and green direction. The background in our portrait shot was reproduced with a slightly bluish cast.

The camera reproduced the portrait scene with very high, even exaggerated sharpness (see details in hair structure). The saturation of the red color (t-shirt) is very high and the skin tones have a slightly high magenta rate.

 Sharpness: The camera showed a very good result in the resolution test. The test chart was reproduced with 3350 of 3648 lines per picture height. The high sharpness is also a result of a very intense sharpness filtering and image processing by the DIGIC 6 processor and causes noticeable overshot and undershot effects. These effects are noticeable in our portrait shot: The hair structure of the model is over-sharpened and has a slight artificial look. In the test box shot the over sharpening of the contrast lines of the large Siemens star causes a strange result: The contrast line has a halo effect that is blurred (elements outside of the plane of focus), so the white halo extends into the black area of the lines.

The test box shot was reproduced with very neutral gray tones in the background. Colors look natural, even though some nuances (red colors) have a very high saturation.

Noise: The noise test results of the Canon G7 X are very good. The camera showed a slightly higher noise level than Canon cameras with an APS-C sized sensor, but this is still a very good result for a compact camera. The luminance noise factor doesn’t cross the 1.0 percent line until ISO 3200. Color noise gets visible in images with ISO 1600 settings and higher: color noise is filtered by an efficient algorithm. Only at ISO 12,800 do the noise filtering effects become annoying.

The camera showed excellent results in the dynamic range tests. The Stouffer chart was reproduced with 11.2 f-stops, which is a remarkably high result for a compact camera. Between ISO 200 and ISO 3200 the camera keeps this high level with 10 to 11 f-stops.

Comments on Video Quality

Due to its good color reproduction with only slightly oversaturated nuances, the camera achieved a high image quality result. The white balance settings are good and the camera neutral and is able to record neutral and coherent colors.

The resolution results are a little disappointing: The camera reproduced the full HD test chart with 684 of 1080 lines per picture height. Because of the low sharpness there are only minor aliasing or Moiré effects.

The results of the noise tests are very good: The camera records nearly noise-free videos up to ISO 1600. At ISO 3200 color noise artifacts become noticeable; at ISO 6400 the noise is clearly visible. Dynamic range results are extremely good and comparable to the results in photo mode. The camera achieved a maximum of 11.7 f-stops, which is a very high result for video recording system.

Pro

compact camera with large image sensor

manual camera settings; Raw mode

shallow depth of field effects possible (due to high speed lens and large sensor)

Con

missing optical viewfinder

These are edited test results and comments by Betterphoto, the testing lab for TIPA (Technical Image Press Association), an organization in which I serve on the Technical Committee.