Resolution Chart Comparison

Comparison cameras:

  • Nikon Coolpix P5000 (10MP, 3.5x zoom)
  • Canon PowerShot A640 (10MP, 4x zoom)
  • Panasonic DMC-LX2 (10MP, 4x zoom)
  • Canon PowerShot G7 (10MP, 6x zoom)

Shots here are of our standard resolution chart (version one or two). This chart allows us to measure the actual performance of the lens and sensor system. It measures the ability of the camera to resolve lines at gradually higher resolutions and enables us to provide a definitive value for comparison purposes. Values on the chart are 1/100th lines per picture height. So a value of 15 equates to 1500 lines per picture height. (Note that on version two of our chart the vertical resolution 1000 - 2000 lines have been horizontally flipped but are otherwise identical). For each camera the relevant prime lens was used. The chart is shot at a full range of apertures and the sharpest image selected.

Studio light, cameras set to auto, settings all factory default. If possible aperture was selected for optimum sharpness. Exposure compensation +0.3 EV to +1.3 EV.
Ricoh GX100 (3,343 KB; 10 MP) Nikon P5000 (2,305 KB; 10 MP)
Panasonic DMC-LX2 (4,821 KB; 10 MP) Canon PowerShot G7 (3,330 KB; 10 MP)

Resolution chart crops

Ricoh GX100 Nikon Coolpix P5000
Panasonic DMC-LX2 Canon PowerShot G7
Ricoh GX100 Nikon Coolpix P5000
Panasonic DMC-LX2 Canon PowerShot G7

Measurable findings

Camera Measurement
Absolute
resolution
Extinction
resolution
Ricoh GX100 Horiz LPH 2000 2600*
Vert LPH 1950 2400*
5° Diagonal LPH +1000 n/a
Nikon Coolpix P5000 Horiz LPH 1750 2050
Vert LPH 1800 2100*
5° Diagonal LPH +1000 n/a
Panasonic DMC-LX2 Horiz LPH 1600 2050*
Vert LPH 1700 2100*
5° Diagonal LPH + 1000 n/a 
Canon PowerShot G7 Horiz LPH 1775 2225*
Vert LPH 1850 2350*
5° Diagonal LPH + 1000 n/a 

* Moiré is visible
# Jagged diagonals
+ Chart maximum
LPH Lines per Picture Height (to allow for different aspect ratios the measurement is the same for horizontal and vertical)
5° Diagonal Lines set at 5° diagonal
Absolute res. Point at which all lines of a resolution bar are still visible and defined, beyond this resolution loss of detail occurs (below Nyquist frequency).
Extinction res. Detail beyond camera's definition (becomes aliased)
n/a Not Available (above the capability of the test chart)
n/v Not Visible (not visible on test results)

They're far from the cleanest results we've ever seen and the default sharpening is way too high, but there's no denying the resolving power of the GX100's lens and sensor combination, which is pretty much the highest we've seen on a compact camera - and knocks its nearest competitors into a hat. Our theory - certainly looking at the rather unpleasant artefacts and moiré as you approach extinction - is that the GX100's sensor has a very weak anti alias filter. Of course getting this much resolution out of a black and white resoution chart under ideal shooting conditions is one thing; seeing a real benefit in 'normal' photography is another thing altogether, and the effects of noise and noise reduction on low contrast detail mean that the GX100's photos are nowhere near as impressive as these results might suggest. Resolution and sharpness also drop off as you move away from the center of the frame.

We should also mention that the GX100 actually produces the highest resolution wide open - stopping down the aperture even a stop or two causes a slight loss of resolution; by the time you get to F5.6 or higher the loss of detail due to diffraction effects might not be noticeable in normal prints, but it is obvious on-screen. Because shooting wide open produces slightly softer corners we'd suggest the optimum shooting aperture ('sweet spot') is probably one stop in from the maximum.