The Canon FS27XX scanners are cases where you need a large gamma to obtain good results (2.0-2.5). Right now the backend collects 12-bit data and converts them to 8 bit with a 4096 byte gamma table (or exports them as 16-bit data). This usually works well; but I admit that there are situations where a few more bits of depth would be welcome.
Even if your scanner has got exposure controls, the question remains whether it scans with fixed settings and manipulates the raw digital data, or whether it really adjusts the gain and zero of the amplifiers. This is probably the point where some companies try to save money; good analog circuitry is expensive. Regards, Ulrich Deiters
