Quality & Size Options

The GH1 can shoot in four different aspect ratios, with three sizes for each. There are two JPEG compression levels, Fine and Standard. You can also shoot RAW files, either alone or combined with a Fine or Standard JPEG.

Dynamic Range (7.76)

The GH1 scored well in our dynamic range testing, though we did find one oddball result that recurred even after running the test again, adding a grain of salt to the results. As shown in the chart below, the dynamic range starts at a modest but acceptable 6.35 stops at ISO 100, lowers slightly through ISO 200 and 400, then somehow expands again dramatically at ISO 800 before resuming its predicted downward path. We believe this is a result of significant noise reduction image processing that kicks in at the ISO 800 level. Ordinarily, we test dynamic range with the camera’s noise reduction system turned off, but that was not possible with the GH1. More on how we test dynamic range.

Once again, the cameras with larger sensors posted superior results, though the GH1 dynamic range is still respectable at this level, especially compared to the dismal showing for the Olympus E-30. Taken as a whole, the GH1 scores well here, meaning it should successfully hold onto details in high-contrast scenes.

Image Stabilization (4.60)

Our tests of the GH1 image stabilization system revealed some benefits, though not a radical improvement. On the plus side, having image stabilization on never had a negative impact on resolution (which frequently occurs), and when the camera is shaking a lot and the shutter speeds are relatively fast (above 1/60 second), the system is quite effective. At slower shutter speeds and high camera shake, though, there was essentially no effect. And shooting with lower shake levels (about what you’d find when holding the camera with both hands), there was a slight benefit gained at slower shutter speeds.

We test a camera’s image stabilization by mounting it in a custom-designed motion-control rig that produces predictable, computer-controlled movements. A slanted-edge test chart is shot multiple times at a range of shutter speeds, both with the rig set to high shake and low shake, and with image stabilization turned on and off. The resulting images are analyzed using Imatest software to determine how effectively the image stabilization system improves actual resolution results. More on how we test image stabilization.

The GH1 uses optical image stabilization, offering three image stabilization modes. Mode 1 employs image stabilization at all times when the camera is in Record mode, and Mode 2 only uses the system when the shutter button is pressed. Mode 3 compensates only for up and down movements, to allow smooth horizontal panning. Of course, stabilization can also be turned off altogether, using a switch on the lens barrel.

The low shake setting reflects typical shooting situations, when you’re holding the camera with two hands. As shown in the graphs above, the system proved effective at limitng horizontal shake at the two shutter speeds that generally mark the lower limits you’d expect to shoot handheld without flash, though at other speeds and for vertical shake the system didn’t offer much improvement.

When we cranked up to shake to high (as if you were trying to shoot one-handed, or while moving), there are significant effects on horizontal shake at 1/250 and 1/125 second shutter speeds, but not much else to brag about.

Image Stabilization Comparison Table			Expand
	Low Shake IS Off	Low Shake IS On	High Shake IS Off	High Shake IS On
1/500
1/250
1/125
1/60
1/30
1/15
1/8

The areas where the system proved effective, and the fact that it didn’t cause problems elsewhere, earned the GH1 a respectable if unexciting score for image stabilization. (We don’t have image stabilization scores for the Nikon D90, hence the missing data in our comparison chart.)