Fuji Super CCD
Fuji's proprietary Super CCD design of CCD image sensor has been the cause of a lot of confusion and hot air on the net, and the occasion for some misleading marketing hype.
This design arranges the actual photo-sensor pixels in an diamond array. This gives them some benefits in laying out the ancillary electronics on the chip, and means that each photo-sensor is physically larger than would be possible in a conventional rectangular array. Larger photo-sensors means lower noise (for any given technology).
However, to be useful, the camera has to produce pictures in standard formats (like TIFF and JPEG), all of which require that the image be represented as a rectangular array of pixels. Fuji handles that by interpolating up to a rectangular array twice the size of the octagonal structure of the actual sensor. Thus many of the Fuji cameras using the Super CCD have a maximum resolution setting of twice the number of photo-sensors on the imaging chip.
Resolution tests with conventional lens test charts tend to show Super CCD cameras as having slightly more resolution than conventional sensor cameras (but nowhere near twice the resolution). However, it's widely believed that the unusual array has simply improved resolution on vertical and horizontal lines, heavily featured in conventional lens test charts, at the cost of resolution on diagonal lines.
Unfortunately, with some models Fuji marketing has attempted to market the maximum file size as the actual resolution, causing a certain amount of bad feeling among digital camera users.
Two series of SuperCCDs are used in Fujifilm's cameras: The SR type with two different pixel sizes, or the HR type with just one pixel size.
Links
- A Fuji press release on the Super CCD sensor is archived at http://www.dpreview.com/news/0001/00013103fujipixel.asp
- newer Fuji document here: [1]
- SuperCCD FAQ in ephotozine.com
