Nikon new release D7100

David Taylor wrote:
On 11/03/2013 13:54, Floyd L. Davidson wrote:
[]
There is no question that given the right scene there
are all kinds of very nasty visible artifacts... moire
patterns.

Yes, given good focus, no camera shake, lenses working
at optimum, no atmospheric blur etc. etc.

Just because moire doesn't appear in every image doesn't
mean there is no aliasing distortion in every image.

Wrong.

No, that is absolutely correct.

If there is no information above Nyquist there can be no aliasing.

But do you actually think that moire is the only way
that aliasing presents?

There is no such thing today, and never will be, as a
camera that meets everyone's expectations. Nikon was
clearly taken by surprise at the popularity of what they
clearly considered a niche market D800E model, and are
unabashedly capitalizing on that with the D7100. It
would be foolhardy for them to decide they know it
actually has no benefit and not produce it.

Perhaps - but let's wait and see all those nasty images
from the D7100 with significant aliasing artefacts.
Let's see how many D7100 are returned to the camera
stores.

How about the images that have aliasing distortion that
is not moire... just added "detail" in places where it
shouldn't be.

--
Floyd L. Davidson http://www.apaflo.com/
Ukpeagvik (Barrow, Alaska)

David Taylor wrote:
On 11/03/2013 19:14, Alfred Molon wrote:
In article , David Taylor says...
Wrong. If there is no information above Nyquist there can be no aliasing.

But there is if you take out the AA filter.

Not if there is no information in the image on the
sensor at that spatial frequency - due to all the
effects I already mentioned.

But typically all of the effects you mention do not
remove sufficient information to avoid aliasing.

It might avoid moire, but that's just one particular
visible effect.

--
Floyd L. Davidson http://www.apaflo.com/
Ukpeagvik (Barrow, Alaska)

Me wrote:
On 11/03/2013 11:35 p.m., Floyd L. Davidson wrote:
snip

I don't think that is a correct evaluation of what
Nikon is doing at all. They try to sell what people
want to buy.

That doesn't mean Nikon is not aware that a 150MP
sensor will provide a better image in terms of aliasing.

http://imaging.nikon.com/lineup/dslr/d7100/sample.htm

I await more sample images with interest.

Do you actually expect Nikon marketing to provide images
that demonstrate a fault???

Indeed they did when the released the D800 and D800E,
IIRC, to demonstrate they issue they put up some photos
on the Nikon Imaging site of a woman wearing a kimono,
with moire clearly visible in the D800E shot.

There have been plenty of A:B comparison photos taken
with D800 and D800E put up on the 'net. With a tiny bit
of low radius USM applied to the D800 shots, they look
just like the D800E shots - I can't tell them apart at
100% pixel view anyway. The AA filter isn't a cure-all
either -
you can still get moire with the D800.

All of the above is exactly true.

Of particular significance is that last line, "you can
still get moire with the D800". That is with all these
other effects that David Taylor believes will remove it
for cameras without an AA filter *and* with an AA filter
in place.

--
Floyd L. Davidson http://www.apaflo.com/
Ukpeagvik (Barrow, Alaska)

On 12/03/2013 12:23 p.m., Floyd L. Davidson wrote:
Me wrote:
On 11/03/2013 11:35 p.m., Floyd L. Davidson wrote:
snip

I don't think that is a correct evaluation of what
Nikon is doing at all. They try to sell what people
want to buy.

That doesn't mean Nikon is not aware that a 150MP
sensor will provide a better image in terms of aliasing.

http://imaging.nikon.com/lineup/dslr/d7100/sample.htm

I await more sample images with interest.

Do you actually expect Nikon marketing to provide images
that demonstrate a fault???

Indeed they did when the released the D800 and D800E,
IIRC, to demonstrate they issue they put up some photos
on the Nikon Imaging site of a woman wearing a kimono,
with moire clearly visible in the D800E shot.

There have been plenty of A:B comparison photos taken
with D800 and D800E put up on the 'net. With a tiny bit
of low radius USM applied to the D800 shots, they look
just like the D800E shots - I can't tell them apart at
100% pixel view anyway. The AA filter isn't a cure-all
either -
you can still get moire with the D800.

All of the above is exactly true.

Of particular significance is that last line, "you can
still get moire with the D800". That is with all these
other effects that David Taylor believes will remove it
for cameras without an AA filter *and* with an AA filter
in place.

A worrying aspect to this, is that at present rate of progress, these
arguments are likely to to continue for a very long time indeed:
http://oi50.tinypic.com/10qgtjn.jpg
g

On 11/03/2013 23:23, Floyd L. Davidson wrote:
[]
Of particular significance is that last line, "you can
still get moire with the D800". That is with all these
other effects that David Taylor believes will remove it
for cameras without an AA filter *and* with an AA filter
in place.

The optical anti-alias filters used with DSLRs are not the same as the
analogue or digital brick-wall filters used in audio, and do not have a
sharp cut-off just below the Nyquist frequency.

As you have now resorted to personal attacks, don't expect any further
response from me.
--
Cheers,
David
Web: http://www.satsignal.eu

On 12/03/2013 02:25, Me wrote:
[]
A worrying aspect to this, is that at present rate of progress, these
arguments are likely to to continue for a very long time indeed:
http://oi50.tinypic.com/10qgtjn.jpg
g

Nice one! There really should not be an argument, as the physics and
signal-processing theory are well understood. The discussion is really
about "when are aliasing artefacts sufficiently weak that they can be
ignored?". Different people will have different requirements.
--
Cheers,
David
Web: http://www.satsignal.eu

David Taylor wrote:
On 11/03/2013 23:23, Floyd L. Davidson wrote:
[]
Of particular significance is that last line, "you can
still get moire with the D800". That is with all these
other effects that David Taylor believes will remove it
for cameras without an AA filter *and* with an AA filter
in place.

The optical anti-alias filters used with DSLRs are not
the same as the analogue or digital brick-wall filters
used in audio, and do not have a sharp cut-off just
below the Nyquist frequency.

The anti-aliasing filters have a much sharper cutoff
than the other various "filters" you have listed. The
simple fact is that lens diffusion is a extremely poor
substitute for a real anti-aliasing filter. Diffusion
virtually does not work! That is because by the time
the highest frequency components are reduced sufficiently,
the lower frequency components have also been reduced to
the point that the image is "soft".

As you have now resorted to personal attacks, don't
expect any further response from me.

What "personal attacks" would that be? Get real!

As for no further response, you have not responded with
anything approaching a valid comment yet; so it might
indeed be nice of you do hide. Just don't deny what you
have already said by claiming that its mention is
somehow an attack on you. It's an attack on the
comments you've made, which are so clearly invalid as to
be inappropriate.

--
Floyd L. Davidson http://www.apaflo.com/
Ukpeagvik (Barrow, Alaska)

On 11/03/2013 19:48, Me wrote:
[]
Indeed they did when the released the D800 and D800E, IIRC, to
demonstrate they issue they put up some photos on the Nikon Imaging site
of a woman wearing a kimono, with moire clearly visible in the D800E shot.

There have been plenty of A:B comparison photos taken with D800 and
D800E put up on the 'net. With a tiny bit of low radius USM applied to
the D800 shots, they look just like the D800E shots - I can't tell them
apart at 100% pixel view anyway. The AA filter isn't a cure-all either -
you can still get moire with the D800.

Yes, you would expect this. Unlike the filters (analogue and digital)
used in audio, the optical low-pass filter used in cameras does not have
a particularly sharp cut-off. It's not a "brick-wall" filter (i.e. one
have near zero response just after Nyquist and near 100% response just
before Nyquist).

As there is not "correct" value for such a comprise filter, you find
some cameras having a slightly stronger AA filter (set at a lower
spatial frequency) and others compromise the other way, set the nominal
cut-off at a higher spatial frequency, and hence produce sharper images,
but with a great possibility of aliasing artefacts.

But if there is no information at or above the Nyquist frequency, there
can be no alias artefacts.
--
Cheers,
David
Web: http://www.satsignal.eu

David Taylor wrote:
On 09/03/2013 11:03, Wolfgang Weisselberg wrote:
David Taylor wrote:

All I'm saying is that it's (excuse the pun) not black and white. Given
a sufficiently high pixel density, the AA filter may not be required
under certain circumstances, and as pixel density increases, those
criteria are increasingly likely to be encountered.

I agree. I just disagree with you that current DSLR pixel
counts are close to a 'sufficiently high pixel density'.

Again, you are putting words in my mouth which I didn't say.

So do we agree that current DSLRs don't have 'sufficiently
high pixel density'?


It appears that
for today's combinations of those variables, with 24 MP DX cameras and
36 MP full-frame cameras we are either approaching or have reached
"sufficiently high" for many people for much of the time.

But here you are saying that current DSLR pixelcounts are
close to a sufficiently high pixel density (at least for
many situations) --- which is what I 'put on your mouth'!


Test cases, super-expensive lenses, and particular subjects excepting.

Good macro lenses are not super-expensive, for example.

-Wolfgang

David Taylor wrote:
On 11/03/2013 23:23, Floyd L. Davidson wrote:

Of particular significance is that last line, "you can
still get moire with the D800". That is with all these
other effects that David Taylor believes will remove it
for cameras without an AA filter *and* with an AA filter
in place.

The optical anti-alias filters used with DSLRs are not the same as the
analogue or digital brick-wall filters used in audio, and do not have a
sharp cut-off just below the Nyquist frequency.

True but irrelevant unless the D800E will have less moire
(or less likely moire) in the identical conditions where the
D800 non-E has moire.

As you have now resorted to personal attacks, don't expect any further
response from me.

Uh --- where *is* the personal attack?

All I can see is the claim that you believe that stuff like
non-perfect lenses, stopping down a bit, imperfect focus
etc. will prevent moire for high pixel count cameras. That may
be a misrepresentation you can correct (e.g. "I agree that the
D800 pixeldensity is too low for preventing moire generally,
but by now I am talking about ..."), but a personal attack?

Unless you read that as "hehe, David is soo stupid, he actually
believes that the D800E can't have moire, the idiot". Which is
not what was written!

-Wolfgang