|Quoting mirage (Reply 16):|
I think dynamic range still have a long way of improvement until it matches what human eye sees.
Quite simply, impossible. The overiding factor is bit-depth and file format. As long as A.net and the web only supports 24 bit images (8 bits per channel, red, green, blue) then you will only have 256:1 dynamic range. The only way around this is completely technical and would involve the internet supporting a higher bit-depth file format, with corresponding compatibility and file size limitations. That's a LONG way off if at all. Because except for professional or high-end photo applications, it's simply not needed for the 99.999% of the commercial business applications of the internet.
A better explanation.
The ability of a camera to capture high bit-depth images requires an image sensor with suitably high dynamic range (at least 4,000:1 for 12 bits per channel), and a correspondingly high A/D converter bit rate and a file image format that supports it. The weakest link in this chain of requirements determines the actual bit-depth of the captured image.
The physically small image sensors used in compact digital cameras provide a dynamic range of around 256:1. These cameras typically use 8-bit A/D converters, allowing up to 256 brightness levels for each RGB color channel. The images are stored as 24-bit JPEG images -- 8 bits per color channel.
The physically larger sensors used in digital SLR cameras have higher dynamic range capability than those used in compact cameras, and are able to capture more subtle tonal graduations. DSLRs are usually equipped with 10- or 12-bit A/D converters, providing distinction for 1,024 or 4,096 brightness levels per channel, respectively. Normally DSLRs offer the option to save the 10 or 12 bits of data per pixel as a RAW file, because JPEG only allows 8 bits of data per channel.
The A/D converter bit rate is normally designed to match the image sensor dynamic range capability. If the image sensor has only a 256:1 (8-bit) dynamic range, a 10- or 12-bit A/D converter may produce a smoother tonal range, but it can only provide 256 brightness levels per channel. Similarly, if image data is captured at 12 bits per channel, storing it as 16-bit TIFF will not create new brightness levels. Storing a 10- or 12-bit image as JPEG or 8-bit TIFF will cause the distinction between some brightness levels to be lost.