At 3:06 AM +0000 1/6/03, olympus-digest wrote:
>Date: Sat, 4 Jan 2003 19:18:51 -0800
>From: Stephen Scharf <scharfsj@xxxxxxxxxxxxx>
>Subject: [OM] Re: olympus-digest V2 #3795
>
> >Date: Sat, 4 Jan 2003 14:43:18 -0500
> >From: Joe Gwinn <joegwinn@xxxxxxxxx>
> >Subject: [OM] The coming generation of 35mm CCD digital cameras
> >
> >I just read the February 2003 issue of Outdoor Photographer.
> >
> ><snip>
> >
> >It's interesting that CMOS sensors are used, not CCDs. CMOS and CCD
> >are different kinds of integrated chip designs. Semiconductor
> >memory chips are CMOS, and CMOS optical sensors are based on memory
> >chips. The difference is that while CMOS sensors are easier to make
> >in large physical chip and pixel-count sizes, their optical
> >performance (especially noise) traditionally isn't nearly as good as
> >CCDs. Apparently, the art of making CMOS sensors has progressed to
> >the point of practicality in photography, although CCDs still reign
> >in scientific applications.
>
>What you say may have true traditionally, but it is no longer with
>the current state of the art for CMOS D-SLR sensors. The reason that
>these mfr's are using CMOS is because they NOW perform BETTER than
>CCD's. The propriety CMOS sensors that Canon developed for their
>D-SLRs are reknown both for their image quality AND their low noise;
>considerably lower than CCD's. Moreover, they consume considerably
>less power, and therefore make their batteries last longer.
I was more or less agreeing, but I don't know that CMOS sensors are *better*
than CCD sensors, in absolute terms. Perhaps cheap CMOS sensors are better
than or at least equal to cheap CCD sensors (plus necessary external logic),
but the astronomy community still uses big, expensive CCD sensors, cooled by
liquid nitrogen. If CMOS sensors can beat CCD sensors, the astronomers will
switch over fairly quickly, as even an expensive sensor is a trivial cost
compared to the cost of a major telescope, so it makes sense to use the best
sensor money can buy.
Joe Gwinn
< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >
|