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Re: CCD vs. Flying Spot



Ronald Martin wrote:

> .... anybody with a MK IIIC in the back room now has the future
> potentional of upgrading to a fully functional and competitive
> answer to the CCD alternative at a fraction of the cost.

Upgrading to "fully functional" would be a start in itself.

> But regardless of what the Physics textbook says, we can achieve a
> 30mhz sweep; an MTF flat to 800 lines; and a S/N ratio of 56db at
> .4 gamma and 59db at linear gamma.

Respectfully, cautiously, and reluctantly with a ten foot pole;
       30mhz.?  Measured where and how?

> ...our experience has taught us flying spots can still fly to new heights.

New Heights?  Is that in Jersey?

> We have yet to examine what can be done with higher sensitivity
> in the cell box, larger CRT surfaces, digital deflection, better optics
> etc., etc.,

The Cell box?  Perhaps a little quieter, but probably nothing dramatically
close to the S/N capability of a CCD scanner with its Solar light source.

Larger CRT surfaces?  How much bigger for what improvement?
A bigger CRT surface, enough to make a worth while difference,
would require new gate optics at the very least.  It would be interesting
though, what the shading, burn, and blemish, geometry, pincusion and
other deflection characteristics would look like with a 14" wide
CRT face?

Better optics?  If it's to improve S/N, again I ask, how much better
is it capable of getting especially by way of new optics?

> The CCD systems, on the other hand, require a huge amount of re-tooling
> to yield increases in resolution or performance.

The larger CRT, the new optics, and all of the etc., etc., mod's wouldn't
require re-tooling?

It's probably more accurate to say that the fact that the CCD scanner
is what it is, is more good than bad.  If the performance characteristics
is originally acceptable, than at least those characteristics will remain
consistent.  It is true though that in order to "scale up", as it were, to
higher resolution would certainly be a redesign, not a re-tooling.
 

Regards,
 

Michael C. Kaye