From: Bart van der Wolf on

<george_preddy(a)yahoo.com> wrote in message
news:1117934606.605577.297030(a)g47g2000cwa.googlegroups.com...
SNIP
> Bayer DSLRs are characteristically blurry and soft because the true
> optical resolution is the resolution of each, individual, tiny,
> subdivided, R, G, or B exposure, [...]

How typical, only half-truths (if any).
Did you forget about lens quality and the anti-aliasing filter, which
are the true source for blur? Resolution is limited by that, the
sampling density, and output magnification.

Bart

From: Big Bill on
On 4 Jun 2005 18:23:26 -0700, george_preddy(a)yahoo.com wrote:

>> >There is absolutely no reason why the three color samples have to be
>> >taken at the same 2D location.
>
>The point is they have to be taken. Bayer hardly takes any color
>samples given their phony monochrome MP ratings. Listing monochrome
>MPs is a scam. There are NO WHERE NEAR enough color samples taken with
>a Bayer sensor to support the advertised color MPs.

You *do* understand, don't you, that the Foveon sensor only samples
monochrome light, right? It's an inherent characteristic of today's
photo sensors used in consumer cameras.The concept that Foveon somehow
managed to capture color where everyone else captures only monochrome
is wrong.
Foveon measures luminance as filtered by the silicon, whereas Bayer
filtered sensors use a Bayer filter. Each then asigns color according
to where each sensor is located.
If you didn't know that, you do know.
So Foveon sensors have no inherent superiority or even ability to
capture olor. All color is asigned by the firmware in the camera. What
differs is *where* the filtering is done.

--
Big Bill
Replace "g" with "a"
From: Big Bill on
On 4 Jun 2005 18:23:26 -0700, george_preddy(a)yahoo.com wrote:

>Interpolation never adds optical resolution.

Exactly. That's why somany are saying the Sigma SDx cameras are 3.43MP
cameras; the 10+MP figure is arrived at through interpolation.

--
Big Bill
Replace "g" with "a"
From: george_preddy on


C Wright wrote:
> On 5/30/05 3:42 PM, in article
> 1117485741.612985.156090(a)o13g2000cwo.googlegroups.com,
> "george_preddy(a)yahoo.com" <george_preddy(a)yahoo.com> wrote:
>
>
> >
> > My point stands. Digital sharpening ruins images because it plows
> > through every pixel blindly, instead of leaving sharpness/blur to
> > optics. That is why film lovers hate digital, the result is flat and
> > lifeless, often even inverted.
> >
> > If you sharpnen digitally, you are simply exceeding the capabilites of
> > your camera at the expense of quality. The only proper way to handle
> > digital images that are breaking down is to print them at the size they
> > were intended. There are no acceptable algorithmic crutches that can
> > substitute for sensor count.
> >
> George (if that is your name) you are a piece of work! Any digital
> sharpening that I have done does not plow through every pixel blindly.
> Sharpening that I am familiar with is adjustable according to threshold,
> radius and degree or amount.

That has nothing to do with lens optics that should produce blur in
some places and sharpness in others.

> Millions of images taken by thousands of
> digital photographers, and sharpened digitally, disprove your assertion that
> they are all exceeding the capabilities of their cameras at the expense of
> quality.

No it doesn't. Digital has a very bad reputation among no-comprimise
photographers, because the overwhelming majority of people who use
digital don't understand that their Bayers take 3 very small RGB
exposures, then combine them while upscaling by 400%. The upscaling
makes the pics blurry and flat. Artifically sharpening from top to
bottom, without regard to optics may make some of the edges arbitrarily
sharper, but flattens the overall image even more, or may even
perceptually invert parts of it.

It is no coincidence digital is criticized by serious photographers and
clients--even if they don't understand why, they know a flat, lifeless,
low resolution image when the see it.

From: george_preddy on


Bart van der Wolf wrote:
> It was already clear that you don't understand the difference between
> monochrome (single color), and spectral band. Each sensel is natively
> sensitive to a spectrum of roughly 350 to 1000 nm, and filters
> restrict that to 3 (sometimes 4) slightly overlapping spectral bands.

Oh, and I thought monchrome sensors always produced a big solid 1 color
rectangle.