Digital BW, The Print

Austin writes:

> Well, if it's just such a fact, then, surely,
> there are many sources you can provide.

Yes, there are.

> Without proper corroboration to your claim,
> your claim has no basis in reality, at least
> as you have stated it.

Your logic is flawed.  The availability or unavailability of corroboration
for an assertion is independent of its objective validity; you cannot assume
that an assertion is without basis in reality in the absence of
corroboration, just as you cannot assume that it is based upon reality with
corroboration.

> I believe you are misinterpreting the actual
> meaning of what you may have heard/read.

I know.  You're entitled to believe whatever you wish.

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

Really?  How does one determine the direction east through one's own
observation?

> That clarifies your statement, and as I said,
> you can not extrapolate 6M pixels based on that.

Because you say so?

> 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.

I have no idea what you are trying to say here.

The resolving power of the human eye is limited to 30 seconds of arc, under
the best conditions conceivable.  Details of this size cover just one cone
cell in the retina.  Details smaller than this cannot be distinguished from
one another, and so any level of detail exceeding this level is unnecessary
for visual presentation.

> 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.

No, it is not.

> You simply can not claim that the eye only has
> 6M equivalent, since you don't know over how
> large an area.

But I do, and I've explained that several times.  The area is that of an
image viewed from a distance roughly equal to its diagonal, e.g., a
10x10-inch image viewed from 14 inches.

> For a 5x7 print, possibly...but for something
> larger than an 8x10 or 11x14, that's simply not true.

For constant proportional viewing distance, it is always true, no matter how
large the print.

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

I've done better.  I've read the physiology texts.  Dissection of the retina
is a pretty good way to determine absolute limits on resolution.

> Oh?  How big is the image?

I'll repeat this again:  The image is viewed from a distance roughly equal
to its diagonal.  In that position, the angular area it subtends needs to
contain 6-8 million pixels in order to match the visual acuity of human
vision.  Just about anything beyond that is wasted; anything below that may
show a lack of detail to those with reasonably keen vision.

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

No, it's not.  Depth of field exists only because human visual acuity is
finite.  There is no such thing as DOF independent of human vision; in the
objective world outside of humanity, the only part of an image that is
actually in focus is the part falling on the plane of focus for a given lens
setting.  Furthermore, DOF is calculated based on accumulated knowledge
concerning maximal human visual acuity; the existence of DOF tables and
markings demonstrates that this knowledge has been stable and available for
many decades.

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

I've already explained image size often enough.  Please refer to any one of
my previous explanations.

> No, Anthony, you're trying to wiggle off the hook.

What hook?

> It's an old tactic of yours when cornered...YOU made
> the claim, so YOU must provide substantiation
> to it.

I'm under no obligation to substantiate anything.  If you don't wish to
believe me, you don't have to.  The same is true for anyone else reading my
posts.  And anyone who wishes to find out for himself can do the research.
I know what he will find, but it will be much more persuasive to him if he
finds out for himself, especially if he has a personality like yours.

> Obviously, you can't, so I must dismiss your claim
> as simply something you've concocted in your mind.

Okay.  I only reply to you to help clarify things for others; what you
accept or dismiss personally is of no importance to me.

> You're missing the point.

You're not making a point.