In article , Richard Schtzl <Richard.Schaetzl@xxxxxxxxxxxxxxxxxxxx>
writes
>Another question,
>
>there was recently an discusion about this new digital-film for every
>camera. In this dicusion somebody claimed, that the equivalent
>sensibility of todays CCDs is around 100-400 ASA and in order to raise
>the sensitivity they had only the posibilty to make the CCD cells
>biger. The propblem is now, that makeing CCD arays biger, will increase
>there price unproportional, because of the difficulty to produce big
>flawless dies (this should be the name of the small silicone pieces).
>If this is true, we will never see CCDs, which could compete with
>classical silver halogen film.
I think you answered the question yourself - that is certainly the
problem right now, but it won't be the problem forever. One thing is
certain - if there is a general requirement within the silicon industry
to make larger die then the problems of defect density will be solved.
At the moment the requirement doesn't exist - memory and microprocessor
technologies are pushing the minimum geometries down in size, so there
is little general requirement to make bigger die, at least as big as a
35mm frame. However, in a few years time there will be little
alternative since the geometries will be so small as to be approaching
quantum limits. While only minor outlets require large die (and no
matter how important we might think it is, imaging sensors are small
beer in the silicon industry) there willnot be sufficient research
funding available to adequately address the problems.
>Which leads me to another question: If read, that the theoretical
>maximum sensitivity of film will be around ISO 819200/60.
>Can somebody (Kennedy?) confirm this?
>
Why do you conclude this? I can't follow your logic in getting to this
figure. In theory a single crystal of silver halide could be activated
by a single photon - so all that is required is that single crystal be
grown sufficiently large. Not much use for imaging purposes though.
Maybe you could explain what you meant, then I might be able to see what
the problem is.
--
Kennedy
Yes, Socrates himself is particularly missed;
A lovely little thinker, but a bugger when he's pissed.
Python Philosophers (replace 'nospam' with 'kennedym' when replying)
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