The D70s has a damn fine imaging sensor the Sony ICX453AQ, as used in the QHY pro OSC camera. This QHY camera performance is "excellent". The bayer matrix on these sensors is reasonably easy to remove thus they are good candidates to
"mono-fy" your DSLR. Which will increase photo sensitivity by 2~3x just from that alone.
The sensor has pixel size ~7.8um which like the Canon 20D (6.4um) is pretty damn good for grabbing photons and achieving a good image scale (arc sec/pixel) for most users. Most more modern DSLRs have pixel size below 5 microns or smaller which is not ideal for photo catching and image scale is all wrong. That said, the newer DSLRs have much lower read/amp & sensor noise.
Problem with the D70 is that it has no live view although this can be overcome by taking a series of shots, enlarging them, and focusing between them for optimum (thus the need for tethering software to do this). The other issue is "amp glow" and general noise, attributed to the design etc. Readout noise of the
D70s is more than twice that of a Canon
20D and newer DSLRs are much much lower than the 20D! The QHY 8 camera cools this D70 sensor so noise is much lower and design has achieved lower noise.
So, over all, the D70 is not bad, particularly wrt to sensor pixel size it just lacks appropriate tethering software like backyard Nikon and is a little noisy. It is well worth a look at. In fact I'd love this sensor in a more modern camera...
already doing that!
