here's what I've seen

http://www.dectris.com/sites/pilatus1m.html

obviously this one is designed for X-ray wavelengths. The pixels are too large and the price too high (I enquired about buying one for my lab, ~£300,000 for a 1MPix one :shock but photon counting detectors do work nicely and remove the problem of saturation.

Of course you still hit the same noise floor when there aren't enough photons as you do with a CCD.

are you talking about photon counting imaging sensors? that would be very interesting, do you have a link for that?

Now that you mention it I've seen something like that for X-rays. At the moment the spatial resolution is diabolical, no where near good enough for visible light imaging, but of course CCDs started out that way so perhaps in a few years....

it all depends on how Hoya choose to handle the situation. Do they want to own a Camera/Lens company?

did they buy Pentax because they want to sell their own products using the Pentax brand to get an easy leg up into a notoriously difficult industry to enter, or because they believe that with financial support and a few tweeks Pentax can be made into a profitable arm of their company while maintaining its own traditions. Or did they just buy Pentax because they wanted the medical imaging bit and cameras came as part of the bundle.

It's too early to really tell, but I haven't seen Hoya stomping all over Pentax up to now.

We all know Pentax can make good lenses and good cameras, deppending on how Hoya handles it, who supplies the cash doesn't necessarily have to make any difference at all to the quality.

if you want to stop someone doing something, the first thing you have to know is how they do it

Maybe so, but the question was how to improve MY Pentax, which is a K10D

glad they're working on it/have fixed it though. One more thing to look forward to for when I finally replace my beloved K10D.

sortof,

the way it works is:

light falls on the sensor and interacts with the semiconductor, creating electron-hole pairs. Readout is in the form of an analogue voltage proportional to the number of electrons generated.

According to the spec sheet for the Kodak sensor which matches the specs of the 645D most closely (we don't know if that's the actual sensor to be used, but the specs will be similar) it has a saturation charge of ~41 thousand electrons.

Since you can't have part of an electron, there are 41000 possible levels of output from that sensor. 2^14 is ~16000 levels while 2^16 is ~65000 levels. So assuming that sensor (which may or may not be the one in use in either camera), 16bit should be better than 14 although not quite as much as might first appear.

Interestingly, though I don't know the specs for the K10D's sensor, that sensor has a similar pixel size and therefore probably similar saturation charge, meaning K10D's 22bit A/D converter is almost certainly mostly hype as there are only about 15.5bits of data there to digitise.


So in short, yes, you're right, we're too close to quantum physics to pretend that true analogue signals exist in nature at this point, but the step up from 14 to 16 bit does appear to be justifiable from the sensor specifications.


What I do find interesting is this really highlights for me how wrong people are when they say things like "yes but CCDs will always keep getting better". Actually it looks like we're getting dangerously close to the theoretical limits of what can be done with some of this stuff.

that would be pretty snazzy, though you'd have to be able to disable it so as to avoid nasally operated AF and metering

the sensor is analogue, it produces a voltage signal which is measured by the A/D converter. The sensor itself doesn't have a "native" bit level.


The other question which as far as I know is yet to be answered is how many bits do you actually get in the RAW files. As Stefan reminded us above, the K10D has a 22bit A/D converter but only outputs 12bit RAW files which limits the benefit.

oh I thought of something else,

somehow link the AF system to white ballance so the AF is accurate under all lighting conditions. It's irritating that it goes funny under tungsten light, right when you want to be using f/1.4 because it's dark so don't have the depth of field to accomodate out of focus shots.

good link