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Resolution Chart Comparison (JPEG and RAW)

Images on this page are of our standard resolution chart which provides for measurement of resolution up to 4000 LPH (Lines Per Picture Height). A value of 20 equates to 2000 lines per picture height. For each camera we use the relevant prime lens (the same one we use for all the other tests in a particular review). The chart is shot at a full range of apertures and the sharpest image selected. Studio light, cameras set to aperture priority (optimum aperture selected), image parameters default. Exposure compensation set to deliver approximately 80% luminance in the white areas.

What we want to show here is how well the camera is able to resolve the detail in our standard test chart compared to the theoretical maximum resolution of the sensor, which for the charts we shoot is easy to work out - it's simply the number of vertical pixels (the chart shows the number of single lines per picture height, the theoretical limit is 1 line per pixel). Beyond this limit (which when talking about line pairs is usually referred to as the Nyquist frequency) the sensor cannot faithfully record image detail and aliasing occurs.

This limit is rarely attained, because the majority of sensors are fitted with anti-aliasing filters. Anti-aliasing filters are designed to reduce unpleasant moiré effects, but in doing so, they also reduce resolution (the relative strength and quality of these filters varies from camera to camera). In theory though, a sensor without an AA filter, when coupled with a 'perfect' lens, will deliver resolution equal to its Nyquist limit. Therefore, even though it may be effectively unattainable with normal equipment in normal shooting situations, an understanding of a sensor's theoretical limit provides a useful benchmark for best possible performance. Nyquist is indicated in these crops with a red line.

On this page we're looking at both JPEG and Raw resolution. For a (more) level playing field we convert the latter using Adobe Camera Raw. Because Adobe Camera Raw applies different levels of sharpening to different cameras (this confirmed) we use the following workflow for these conversions:

  • Load RAW file into Adobe Camera RAW (Auto mode disabled)
  • Set Sharpness to 0 (all other settings default)
  • Open file to Photoshop
  • Apply a Unsharp mask tuned to the camera, usually 100%, Radius 0.6, Threshold 0
  • Save as a TIFF (for cropping) and as a JPEG quality 11 for download
JPEG (3648 x 2736) 1.6MB RAW (3648 x 2736) 11MB

Vertical resolution

JPEG
RAW

Horizontal resolution

JPEG RAW

The Canon Powershot G12 gives impressive performance in our resolution tests, and all nine lines of our test chart are accurately resolved up to around the 2200 LPH point from the camera's JPEG output, and approximately 2300 LPG when shooting RAW. This is impressively close to the Nyquist limit, which is equal to the G12's vertical output pixel count - i.e. 2736 pixels/LPH. In terms of resolution, the G12 compares very well to the three cameras in our high-end compact camera group test, published late last year.

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Comments

Total comments: 4
white shadow

I am revisiting this review after almost 5 years of owning and still using the Canon G12. Despite all these years of use, the camera is still going strong and still one of my favourite compact cameras I have, the other being the Ricoh GR.

I am still amazed that this humble camera can produce excellent 12" X 18" prints over the years. It goes to show that one should not underestimate a small sensor compact camera like the G12.

It is unfortunate Canon is not making compact cameras this way with all the dials of the G12 anymore.

Five years have passed and I am not letting this camera go. There should still be many years of life to go.

Comment edited 5 minutes after posting
2 upvotes
cgarrard

you aren't alone ;) I've written reviews on the G10/12/15/16.. the are all excellent cameras, but yes, I prefer the extra dials and heft of the G10/11/12 for most shooting. Canon should go back to more dials on the next G (g7 isnt a G to me, its an S )

Carl

1 upvote
white shadow

I am now here in Chiangmai/Chiangrai for about 10 days for a short discovery trip to shoot the Karen hill tribe. If you haven't been here you should make this place your next trip. Great place for street photography, food and even some wildlife photography.

Despite bringing along my "better cameras" like my full frame DSLR, a micro 4/3 camera with 4 lenses and a Ricoh GR, the Canon G12 is used the most. It is reliable, have very good colour and easy to use that it always capture the right moments without fail. Great for street portraits and intrepid photography. The excellent photo quality is also due to its CCD sensor instead of a CMOS one. Unfortunately, we don't get this anymore. The dials and simple UI are what make this camera outstanding even after 5 years.

The best camera is still the one that has the ability to capture the moments accurately the most.

Comment edited 4 minutes after posting
1 upvote
cgarrard

"The best camera is still the one that has the ability to capture the moments accurately the most."

Exactly.

Carl

0 upvotes
Total comments: 4