Digital BW, The Print

Anthony,

> > What is the source of the claim?
>
> As I've explained, it's not a claim, it's a fact.  I don't need a source.

Well, if it's just such a fact, then, surely, there are many sources you can
provide.  Without proper corroboration to your claim, your claim has no
basis in reality, at least as you have stated it.  I believe you are
misinterpreting the actual meaning of what you may have heard/read.

> Just as most people don't need a source to
> believe that the sun rises in the east...

One can use one's own observation to corroborate that fact, so your example
does not apply.

> > It's physiology that the human eye has
> > variable resolution, with the highest
> > area being in the very center ...
>
> That's what I mean by the "scanning action of the eye."  These figures
> correspond to the region of greatest acuity in the retina, the fovea
> centralis; this zone is scanned over an image by the eye in order
> to provide
> detailed vision over a larger area.

That clarifies your statement, and as I said, you can not extrapolate 6M
pixels based on that.  It's simply so easy to refute your claim based on a
simple inkjet print.  A 13 x 19 inkjet print at 720 DPI has 128,044,800
dots...what ever you want to call them.  I know that they are dithered, but
the resolution of they eye can still pick up very small detail in such a
print, so let's even say that 300 PPI for a non-dithered image, at 13 x 19
is 22,230,000...and I don't now about you, but I have an entire wall of 13 x
19 images that I can scan across and not move from my spot.

Additionally, it's required to have MORE resolution than the human eye can
discretely discern in order to have smooth transitions between changes in
tones.  Same issue with number of tones that an inkjet prints...vs...what we
can physically discern.  You actually don't want to discern tones!

You simply can not claim that the eye only has 6M equivalent, since you
don't know over how large an area.  For a 5x7 print, possibly...but for
something larger than an 8x10 or 11x14, that's simply not true.

> The resolution outside the fovea is so low that it makes virtually no
> contribution to the type of eyesight required to view photographs.

I disagree with that.  Have you ever looked at a mural?

> The figure of 6-8 megapixels, then, is the figure obtained by the scanning
> of the fovea over the entire print or image.

Oh?  How big is the image?

> > ... so you can't extrapolate the real
> > "resolution" of the human field of view as you have.
>
> Yes, I can, and I have,

Of course you can, but your initial premise is simply mistaken, and because
of that, you simply at the incorrect conclusion.

> This
> is how depth-of-field markings were calculated on camera lenses decades
> before my birth.

Er, no, that's really a different issue.

> The circles of confusion...

I know precisely how COC and DOF are calculated, thanks...and as I've said,
it's simply not enough information to draw the conclusions you have drawn.

> > It's a physical fact that your eye has higher
> > resolution in the center, and decreased resolution
> > around the periphery.
>
> I'm aware of this, and the figures I give are for the fovea.  Since the
> fovea is scanned over the entire image, its resolution applies to
> the entire
> image.  Even so, the total figure is 6-8 megapixels.  That's all you need.

Well, I simply know that to not be true, again, it depends on what size the
image is.

> > Then, of course, you can point me to an established
> > resource that supports your claim?
>
> No, you must do your own research, and your posts will be much more cogent
> if you undertake this before preparing any further replies to my posts.

No, Anthony, you're trying to wiggle off the hook.  It's an old tactic of
yours when cornered...YOU made the claim, so YOU must provide substantiation
to it.  Obviously, you can't, so I must dismiss your claim as simply
something you've concocted in your mind.

> > The number of pixels for a camera is ENTIRELY
> > UNRELATED to what the resolution of the human
> > eye is.  It depends on what size the resultant
> > image is!
>
> Images are typically viewed from distances that fall within a
> fairly narrow
> range in proportion to the print.  That's why everyone does not insist on
> shooting Tech Pan in 8x10 sheets, and it's also why virtually nobody is
> happy with prints made from aging digicams with 320x200-pixel sensors.

You're missing the point.

Austin