RE: [Rollei] [OT] digital question

["Austin Franklin" <darkroom >]

> At 04:48 PM 5/20/2003 -0600, you wrote:
> >This is off-topic, but I'm hoping some of you digi-wizards out there can
> >help.  I've noticed the newer and cheaper generation of digital cameras
> >(Nikon 3100, Canon A70) offer 3.2 megapixels but have a sensor array the
> >same size as their 2.1 MP models (1/2.7"), while the older generation of
> >3.2 MP models had an array size of 1/1.8".  Obviously, you still have the
> >same number of pixels to work with, but I'm wondering if there should be
> >any theoretical or real effect on image quality with the smaller arrays.
> >I've downloaded some images from the A70 and they look really
> nice.  To my
> >eyes they compare favorably with images from the older,
> larger-array models
> >like the Nikon 885.
> >
> >Anyone have any thoughts on this?  TIA...Phil
> >
> >Phil Swango
>
> Hi Phil,
>
>    There is a relation (that someone else might know better than
> I) between
> the pixel spacing and amount of noise. The smaller the CCD with a higher
> density will have a higher noise ratio than a larger sensor with larger
> pixel spacing. So the newer and cheaper digicams are of higher
> density and
> higher resolution, but it comes at a price. Some people are
> willing to put
> up with the noise for a cheap digicam, others are not, it's up to you. I
> seem to remember that someone on the list here actually designs
> CCD or CMOS
> digital sensors. Maybe they will be able to give you a better and more
> definitive explanation.

Hi Rick and Phil,

It may be me you are referring to...but I design digital imaging devices,
not the actual sensors...I design using them.  What you said is basically
true, typically smaller sensors of the same "technology" (meaning how they
are made, the actual structures of the cells etc.) will have higer noise.
But, as "technology" improves, the sensor may be able to be made smaller
with the same or less noise.  I'd have to see the specs for the two sensors
to actually say what the differences are.

Regards,

Austin

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