Previous page Next page

ISO / Sensitivity accuracy

The actual sensitivity of each indicated ISO is measured using the same shots as are used to measure ISO noise levels, we simply compare the exposure for each shot to the metered light level (using a calibrated Sekonic L-358), middle gray matched. We estimate the accuracy of these results to be +/- 1/6 EV.

Indicated
ISO value
Samsung NX10
measured value*
Panasonic GF1
measured value*
Nikon D5000
measured value*
ISO 100
ISO 100
ISO 125
ISO 100
ISO 200
ISO 200
ISO 250
ISO 200
ISO 400
ISO 400
ISO 500
ISO 400
ISO 800
ISO 800
ISO 1000
ISO 800
ISO 1600
ISO 1600
ISO 2000
ISO 1600
ISO 3200
ISO 2500
ISO 4000
ISO 3200

This means the GF1 is having to use shutter speeds one third of a stop faster than the other cameras on test in order to give the same overall image brightness. The NX10 meanwhile, isn't quite as sensitive at its ISO 3200 setting as it should be, so needs shutter speed one third of a stop longer.

ISO Sensitivity / Noise levels

ISO equivalence on a digital camera is the ability to increase the sensitivity of the sensor. This works by turning up the "volume" (gain) on the sensor's signal amplifiers (remember the sensor is an analogue device). By amplifying the signal you also amplify the noise which becomes more visible at higher ISO's. Many modern cameras also employ noise reduction and / or sharpness reduction at higher sensitivities.

To measure noise levels we take a sequence of images of a GretagMacBeth ColorChecker chart (controlled artificial daylight lighting). The exposure is matched to the ISO (ie. ISO 200, 1/200 sec for consistency of exposure between cameras). The image sequence is run through our own proprietary noise measurement tool (version 1.5 in this review). Click here for more information. Room temperature is approximately 22°C (~72°F), simulated daylight lighting.

Samsung NX10 vs Nikon D5000 vs Canon EOS 550D/T2i vs Panasonic DMC-GF1

  • Samsung NX10: Pentax 50mm F1.4 (via adapter), Manual Exposure, WB tuned to neutral,
    Default Parameters, Standard Picture Wizard, NR Off, JPEG 14MP / Super Fine

  • Nikon D5000: Nikkor 50 mm F1.4 G lens, Aperture Priority, Manual WB,
    Default Parameters, Standard Picture Control, Gradation Normal, NR Normal, JPEG Large / Fine

  • Canon EOS 550D: Canon 50 mm F1.4 USM lens, Aperture Priority, Manual WB,
    Default Parameters, Standard Picture Style, NR Standard, JPEG Large / Fine

  • Panasonic DMC-GF1: Olympus 50mm F2.0 Macro (via adapter), Manual Exposure, Manual WB, Default Parameters, Standard Film Mode, Default Parameters, Noise Reduction Standard (0), JPEG Large / Fine
  Samsung NX10 Nikon D5000 Canon EOS 550D Panasonic GF1
ISO 100
ISO 200
ISO 400
ISO 800
ISO 1600
ISO 3200

The NX10 comfortably keeps pace with its APS-C peers (the EOS 550D/Rebel T2i and Nikon D5000) all the was up to ISO 800. At ISO 1600 its noise reduction is significantly reducing it in detail compared with the Canon, though it's still on a par with the Nikon. Only at ISO 3200 does it really fall behind, with large blotches of chroma noise and splodgy noise reduction removing all the fine detail.

It's a little harder to compare to the GF1, given how different an approach the two cameras take to noise reduction - the Panasonic doesn't suppress luminance noise to nearly the same degree but retains more detail as a result. In terms of detail, the Samsung doesn't appear to offer any great advantages at high ISO.

Noise graphs

  Samsung NX10 vs Nikon D5000 vs Canon EOS 550D vs Panasonic DMC-GF1
Chroma
Black
Gray

Measured ISO sensitivity is on the horizontal axis of this graph, standard deviation of luminosity on the vertical axis.

The graphs tell the same story that the image crops began - the Samsung does very well until ISO 1600, at which point both the noise really starts rising. It's worth bearing in mind, though, that although the Panasonic is showing higher noise figures, it's also retaining considerably more detail. Because the Samsung has more pixels than the Nikon or Panasonic, noise would be still lower when considered on a whole-image basis.

RAW noise

Raw noise compared (ACR)

We use a standard raw converter (Adobe Camera Raw usually, as it is often the first third-party software to offer support for new cameras), in order to provide a comparatively level playing field. We can't be sure ACR is doing exactly the same thing to all files but its more neutral than using the manufacturers' software (which is often based on the same algorithms as their in-camera processing).

Noise reduction is set as low as possible

  Samsung NX10 Nikon D5000 Canon EOS 550D Panasonic GF1
ISO 100
ISO 200
ISO 400
ISO 800
ISO 1600
ISO 3200

RAW Noise graphs

  Samsung NX10 vs Nikon D5000 vs Canon EOS 550D vs Panasonic DMC-GF1
Chroma
Black
Gray

In RAW the NX10 is rather less convincing - producing more noise than ever other camera here. This means it's having to apply greater levels of noise reduction to achieve the low noise measurements shown in its JPEGs.

Previous page Next page
38
I own it
1
I want it
20
I had it
Discuss in the forums

Comments