I'm sure this topic has passed many times.
So this topic is redundant, but it will only be short-lived :-)
Most current digital backs have a dynamic range of 12 f-stops.
Current DSLRs promote a 14bit-A/D conversion, MFDB are in the 16bit range.
My understanding is that this bit-talk referes to color depth, so my question is:
How many f-stops can a DSLR handle? And why are they more limited than MFDB's?
Authors note: This topic is in no way a do-I-really-need-a-25k-digital-back-when-I-can-buy-a-5k-canikon? So please, don't go where I didn't :-)
An interesting and somewhat complex set of questions. Your first question "How many f-stops can a DSLR handle?" is difficult to answer because dynamic range is a moving target on any digital sensor, camera or back. It changes based on a number of factors. It can be influenced by ambient temperature, cooling capability, exposure time and package electronics–among other factors.
For instance, for every 6.3°C increase in sensor temperature of the Kodak 39mp sensor the dark current noise will double and decrease dynamic range by about one stop.
The measure for dynamic range is not the bit-depth of the A/D converter. The A/D converter can not replace dynamic range that the analog sensor (CCD or CMOS) is unable to capture. Knowing the bit-depth of the A/D converter does not tell you the dynamic range of the capture device.
Also, the specification given by manufacturers of "f-stops of dynamic range" is not standardized. It is based on the maker's standard for a given set of conditions.
The measure of dynamic range is signal-to-noise ratio at a specific temperature. As mentioned above, increases or decreases in sensor temperature have a dramatic effect on dynamic range (signal/noise ratio). So, depending on a host of variables, the dynamic range varies.