Compared to... (contd.)

Now we'll compare the DiMAGE S304 to a few other cameras from our test archives. Here we're comparing colour and resolution to the Nikon Coolpix 995, Sony DSC-S75 and Olympus C-3040Z.

Colour Chart Comparison

Colour charts are shot in daylight, Auto White Balance, EV compensation +0.3 (all cameras), measured light ~10 EV. This test is also dependent on the accuracy of the camera's auto white balance, the colour charts are shot in daylight but some camera's white balance is better than others. All cameras are given 20 seconds to "settle" before the shot is taken.

As per other samples in this review the S304 image has been converted to the sRGB colour space using the Minolta Image Viewer application [info].

Minolta DiMAGE S304 (Resaved as sRGB) Nikon Coolpix 995
Sony DSC-S75 Olympus C-3040Z

As you can see the S304 does a fairly good job (after being run through the Image Viewer Utility), however its reds are noticeably tinged towards orange.

In the table below we're only measuring colour. The RGB values were measured from a VGA reduced image (to average colours, remove noise and eliminate JPEG artifacts) using the Eyedropper tool in Photoshop with a 5 by 5 Average Sample Size.

Patch

Minolta
DiMAGE S304

Nikon Coolpix
995

Sony
DSC-S75

Olympus
C-3040Z

Black 27,31,34 23,26,24 22,23,25 30,30,30
       
Middle Gray 82,93,95 98,99,98 92,95,96 102,102,100
       
White 217,221,221 213,210,210 193,195,194 201,202,201
       
Magenta 215,53,115 206,38,118 200,7,130 205,36,103
       
Red 211,54,48 197,29,47 204,0,25 195,29,36
       
Yellow 212,216,37 217,185,26 185,189,15 191,185,61
       
Green 16,134,64 9,136,57 35,140,34 8,136,61
       
Cyan 1,144,208 51,162,199 41,154,199 31,157,183
       
Blue 42,32,101 53,45,104 33,25,150 41,33,84
       

Minolta DiMAGE S304 observations:

  • White balance has left image with a very slight blue cast
  • Yellow and green are good
  • Red looks orange (too much green / blue value)
  • Blue is just as dull as Coolpix 995 / Olympus C-3040Z

Resolution Comparison

Shots here are of the PIMA/ISO 12233 standard resolution test chart (more of which are available in our comparison database). This resolution 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 8 equates to 800 lines per picture height.

Studio light, cameras set to auto, all settings factory default. Exposure compensation +0.7 EV for all cameras.

Horizontal resolution Vertical resolution 5 degree diagonal res.
Minolta DiMAGE S304
Nikon Coolpix 995
Sony DSC-S75
Olympus C-3040Z

Measurable findings (three measurements taken for each camera):

Camera Measurement Absolute Res. Extinction Res.
Minolta DiMAGE S304 Horiz LPH * 950  * 1250 
Vert LPH * 950  * 1250 
5o Diagonal LPH 850  n/a 
Nikon Coolpix 995 Horiz LPH * 900  * 1300 
Vert LPH 900  1400 
5o Diagonal LPH 900  n/a 
Sony DSC-S75 Horiz LPH 1050  1400 
Vert LPH 1050  1500 
5o Diagonal LPH 1000  n/a 
Olympus C-3040Z Horiz LPH * 1000  * 1300 
Vert LPH * 1000  1350 
5o Diagonal LPH * 900  n/a 

* Moiré is visible

Definition of terms:

LPH Lines per Picture Height (to allow for different aspect ratios the measurement is the same for horizontal and vertical)
5o Diagonal Lines set at 5o diagonal
Absolute Resolution Still defined detail (below Nyquist frequency*)
Extinction Resolution Detail beyond camera's definition (becomes a solid gray alias)
n/a Not Available (above the capability of the test chart)
n/v Not Visible (not visible on test results)
* Nyquist frequency defined as the highest spatial frequency where the CCD can still faithfully record
image detail. Beyond the Nyquist frequency aliasing occurs.

For absolute resolution the DiMAGE S304 fairs well, although it's not our highest resolution 3 megapixel to date. On the negative side the S304 exhibits fairly strong moiré colour interference from around 900 lines/picture height in both horizontal and vertical directions.