This is a screen shot showing comparison between several key frames in a test made using 1/3rd stop intervals, with 1/10th stop repeat accuracy from studio flash, to show how Hi200 works in the Alpha 100. The values used by the Alpha 100 may not be identical to the earlier models - I was told that with the D7D, the Hi and Lo Zone Matching used ISO 160 sensor EI, and ISO 100 and 250 metering EI respectively. On the basis of these tests, the A100 appears to use ISO 100 as the sensor EI and ISO 200 as the metering EI, for Hi200.

Note that the RAW file density (ACR is used to create unmodified raw previews here by setting defaults to match the in-camera JPEG as closely as possible) is the same for Hi200 at f/16 and ISO 200 at f/22 - one stop underexposed. To yield a normal raw density, Hi200 must be overexposed by one stop to f/11. But the Hi200 JPEG created in camera is if anything brighter in the shadows than the 'correct' ISO 200 f/16 JPEG, while holding the bright backlit area behind the target (a zone lit to clip the highlights) well.

If you shoot raw with JPEG, the only effect of enabling Hi200 on the A100 is to produce roughly one stop of underexposure all the time. To get the benefit of the Hi200 tone curve, you must either use the in-camera JPEG, or use Sony Image Data Converter. IDC will completely remove the differences visible in ACR, by using embedded JPEGs for previews - and by applying 'High' Zone to the raw conversion automatically for the Hi200 raw.

Although the raw file data is not affected by the zone matching, and other programs can not read the tags which mark the zone matching, IDC will process the image identically to the in-camera JPEG by default and you will never be aware that the raw file contains what amount to 1 stop underexposed pixel values overall.