Entry level Nikon 24mp?!

Wolfgang Weisselberg wrote:
Floyd L. Davidson wrote:
Wolfgang Weisselberg wrote:
Floyd L. Davidson wrote:
Paul Furman wrote:
Floyd L. Davidson wrote:
Eric wrote:
rOn Tue, 10 Apr 2012 17:33:35 +1000, wrote:
"Eric wrote:
The Nikon D1 was 2.4 Mp.

The actual sensor has 10,655,552 sensor locations, and 4 each of
them are binned in order to produce a single value for the Bayer
Encoded RAW file. The binning is done in hardware.

They should do that with any new 24MP camera, as an option at least.

It's probably not possible implement as a switchable option in
hardware without introducing serious noise.

Noise is not the problem. Electronics, not being a CCD and
having to bin over large spaces (to bridge between 4 reds or
blues) is. Image quality is too, then.

Yes. That adds up to *noise* is the problem.

That's like reasoning that drugs are the problem
for accidents on icy roads.

At least *try* to understand that not all image problems are
noise and that not all technological problems result in noise.

Childish arguments to no benefit are just not worth
a reply.

Some Canons have a smaller optional raw format.

Canon's "smaller option raw format" is not a raw format.

It is a raw format, but not in the sense that you get the
direct output of each sensel.

It simply is not a raw format.

It is not an image, it has to be cooked to provide an image,
therefore it's raw.

It has already been "cooked".

It is interpolated data, not
raw data that needs to be interpolated.

Could you expand on that?

That's a clear enough statement in itself. Do a little
research yourself and learn what it is.

In practice those that use it,
the advantages they use RAW for, but without having to store
all the data they don't care for in first place.

It's just a TIFF RGB format. Whoopee. They could shoot
JPEG to get the same effect...

News for you: CR2 is a JPEG RGB format.

It's a TIFF file format, with raw sensor data. It's not
an RGB image format. But the sRAW format is just that.

What's not clear to me, is whether that makes a sharper low res image in
the same way reducing after raw conversion will do.

Resizing to a smaller resolution does not make an image
"sharper" as such.

It thins the borders between ajdacent areas, just as wavelet
sharpen does. So not only the acutancy can rise.

No reply?

That *is* acutance. That's why USM is more effective on down
sized images and a high pass Sharpen is more effective on up
sized images.

It removes high frequency detail,

which, depending on the image and the amount of downsizing,
isn't there in first place (excluding high frequency noise).

Well, its true that if you shoot pictures of gray cards, there
isn't much high frequency detail. Otherwise there is.

Please do some FT on real world images, and prove your claim.

Again, childish arguments to no benefit are not deserving of a
reply.

From bayer patterns being very good but not perfect in the
restoration of high frequencies ( SQRT(2) of the pixel to pixel
distance) over the roll-off of AA filters down to camera shake,
slight misfocus and subject movement ... there can be many reasons
why high frequency detail simply isn't there in first place.

But for good photographers, who use good technique, there is
almost always enough high frequency detail to make a very
visible difference.

A "visible difference" between what and what? Do try a double
blind test on printed (or web sized) images, one 'original'
from bayer and one downsized to 70% ...

Another childish argument.

That is *precisely* why applying Sharpen almost always has a
significant effect.

'significant' meaning you can measure the difference, but you
cannot see it? 'significant' meaning a difference of several
orders of magnitude?

I did not make that distinction, so your attempt to make it is
just another example of the many childish arguments in your
article.

It's a *visible* effect.

BTW, whether Sharpen has a 'significant effect' depends very much
on where the high pass filter cuts off lower frequencies.

Whoopee.

and in
that sense reduces sharpness.

Which is irrelevant, unless you're actually seeing it at a
distance and resolution where such detail, if it was were,
would be visible. Most images just aren't viewed at 100%.

Prints commonly are.

'viewing distance'. 'loupe'.

Most photos aren't
all that sharp at full resolution, if for no other reason than the
existence of an antialiasing filter.

That isn't really true. The AA filter, in a properly processed
image, has just about exactly the same amount of high frequency
detail as a similar camera without the AA filter, except that at
frequencies very close to the Nyquist limit the signal to noise
ratio will be slightly reduced on the camera with the AA filter
(and conversely on camera without the AA filter the SNR will be
reduced by aliasing distortion throughout the frequency
spectrum).

That assumes a hard cut-off of the AA filter. I understand
that that's pretty hard to do in the real world.

It is virtually impossible to do, but that is not required
for what was described.

The high frequency components just below the Nyquist Limit are
reduced by the AA filter, but by no means eliminated because the
filter is not particularly sharp. Because of that the actual
frequency where maximum frequency distortion occurs will
intentionally be placed just above the Nyquist Limit. Most
designs will hit a minimum and at higher frequencies will have a
slope similar to the slope at lower frequencies. (On some that
slope may be very steep at frequencies well above the Nyquist
Limit, but hopefully that will also be at the upper limits for
any given lens that might be used, so between the filter and the
lens there is a very low response level at those frequencies
too.)

Whatever, the AA filter is a Low Pass filter, and a High Pass
filter can be applied in post processing with an almost opposite
frequency response to perfectly correct the rolloff provided
by the AA filter. At frequencies just below the Nyquist Limit (and
be aware that here are absolutely *no* frequencies above the Limit) the
correction from the Sharpen HP filter is at its highest. The filter
increases noise just as much as it increases desired signal, and
that is why the SNR is worse than it would without the AA filter but
the frequency response will be almost precisely the same.

Of course at lower and lower frequencies there is less and less
correction by the Sharpen filter, and therefore less and less
change to the SNR compared to an image taken without the AA filter.

So, where do I get a high pass filter that works exactly to
counteract the AA filter, and why do other filters provide
better results when the result is inspected visually?

What are you mumbling about?

In any case the reason images are apparently not sharp when
viewed at 100% is because a Bayer Color Filter encoded camera
simply cannot produce a tone transition in less than some number
of pixels, and the larger the demosiacing matrix the higher the
minimum for transition, as well as the more accurate the colors.

Actually, you are wrong here. Intelligent demosaicing
detects borders and doesn't smear them, irrespective of their
size. It's not a simple averaging process.

You simply cannot get a one pixel length tone transition,
without applying a Sharpen HP or USM filter. Yes different
demosaicing algorithms can produce sharper results, but absent
some form of sharpen, there are no truly "sharp" transitions.

What is 'truly "sharp"'? A single hot pixel? An aliased
line?

More childish argument rather than any real attempt at discussion.

I see lots of transitions from A to B with just one pixel in
between --- and since I cannot align the camera pixel borders
perfectly with the image ...

Actually, looking at resolution tests, one gets transitions
of 1.5 and less pixels.

No you don't.

Of course that isn't really "sharpness", but acutance, and again
it can be increased with either a high pass filter (Sharpen) or
application of Unsharp Mask.

Of course that's really sharpness, as such an averaging process
would reduce or destroy the visibility of e.g. thin parallel
lines, thus reducing resolution drastically.

There is no actual increase in resolution. All that happens
with either USM or an HP filter is that the difference between
existing tone transition edges in increased.

Ah, how exactly do you define 'resolution' and how do you
define MTF?

Standard definitions are fine. You can look them up any time
you want to carry on an adult discussion.

And if you can't, I will not respond again.

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

Floyd L. Davidson wrote:
Wolfgang Weisselberg wrote:
Floyd L. Davidson wrote:
Wolfgang Weisselberg wrote:
Floyd L. Davidson wrote:
Paul Furman wrote:
Floyd L. Davidson wrote:
Eric wrote:
On Tue, 10 Apr 2012 17:33:35 +1000, wrote:
"Eric wrote:
The Nikon D1 was 2.4 Mp.

The actual sensor has 10,655,552 sensor locations, and 4 each of
them are binned in order to produce a single value for the Bayer
Encoded RAW file. The binning is done in hardware.

They should do that with any new 24MP camera, as an option at least.

It's probably not possible implement as a switchable option in
hardware without introducing serious noise.

Noise is not the problem. Electronics, not being a CCD and
having to bin over large spaces (to bridge between 4 reds or
blues) is. Image quality is too, then.

Yes. That adds up to *noise* is the problem.

That's like reasoning that drugs are the problem
for accidents on icy roads.

At least *try* to understand that not all image problems are
noise and that not all technological problems result in noise.

Childish arguments to no benefit are just not worth
a reply.

You not understanding does not make my arguments childish.
In fact, a child would understand ...


Some Canons have a smaller optional raw format.

Canon's "smaller option raw format" is not a raw format.

It is a raw format, but not in the sense that you get the
direct output of each sensel.

It simply is not a raw format.

It is not an image, it has to be cooked to provide an image,
therefore it's raw.

It has already been "cooked".

If that was true, it would be equivalent to a JPEG. It's not.


It is interpolated data, not
raw data that needs to be interpolated.

Could you expand on that?

That's a clear enough statement in itself. Do a little
research yourself and learn what it is.

I'm so *not* going to do your homework for you.
If you don't have proof for your claims, so be it.


In practice those that use it,
the advantages they use RAW for, but without having to store
all the data they don't care for in first place.

It's just a TIFF RGB format. Whoopee. They could shoot
JPEG to get the same effect...

News for you: CR2 is a JPEG RGB format.

It's a TIFF file format, with raw sensor data. It's not
an RGB image format.

TIFF is a whole class of formats. And yes, the CR2 is an RGB
format --- it has to be! What other colours are there on the
sensor? And it's compressed with a JPEG lossless compression.

But the sRAW format is just that.

Or so you say.


It removes high frequency detail,

which, depending on the image and the amount of downsizing,
isn't there in first place (excluding high frequency noise).

Well, its true that if you shoot pictures of gray cards, there
isn't much high frequency detail. Otherwise there is.

Please do some FT on real world images, and prove your claim.

Again, childish arguments to no benefit are not deserving of a
reply.

Actually *measuring* the frequencies would be childish and not
deserving a reply ...

Well, that speaks volumes.


From bayer patterns being very good but not perfect in the
restoration of high frequencies ( SQRT(2) of the pixel to pixel
distance) over the roll-off of AA filters down to camera shake,
slight misfocus and subject movement ... there can be many reasons
why high frequency detail simply isn't there in first place.

But for good photographers, who use good technique, there is
almost always enough high frequency detail to make a very
visible difference.

A "visible difference" between what and what? Do try a double
blind test on printed (or web sized) images, one 'original'
from bayer and one downsized to 70% ...

Another childish argument.

Actually *testing* your claims is a childish argument?

Well, that speaks volumes.


That is *precisely* why applying Sharpen almost always has a
significant effect.

'significant' meaning you can measure the difference, but you
cannot see it? 'significant' meaning a difference of several
orders of magnitude?

I did not make that distinction,

Exactly, you said just 'significant'. You made no distinction
at all. And that can mean anything between "just measurable"
and "everybody dies" --- on the very same slide even --- as the
Columbia Accident Discovery Board noted.

so your attempt to make it is
just another example of the many childish arguments in your
article.

Asking for clarification is childish?

Gee, I sure don' wanna be grown up like you, you have to
guess everythin' and can't never ask.


It's a *visible* effect.

Rather than a *tactile* effect? Under which circumstances does
it happen to be "almost always" visible to the naked eye at normal
viewing distance on a print or web display?

BTW, whether Sharpen has a 'significant effect' depends very much
on where the high pass filter cuts off lower frequencies.

Whoopee.

Which means that "almost always" is wrong.


That assumes a hard cut-off of the AA filter. I understand
that that's pretty hard to do in the real world.

It is virtually impossible to do, but that is not required
for what was described.

The high frequency components just below the Nyquist Limit are
reduced by the AA filter, but by no means eliminated because the
filter is not particularly sharp. Because of that the actual
frequency where maximum frequency distortion occurs will
intentionally be placed just above the Nyquist Limit. Most
designs will hit a minimum and at higher frequencies will have a
slope similar to the slope at lower frequencies. (On some that
slope may be very steep at frequencies well above the Nyquist
Limit, but hopefully that will also be at the upper limits for
any given lens that might be used, so between the filter and the
lens there is a very low response level at those frequencies
too.)

Whatever, the AA filter is a Low Pass filter, and a High Pass
filter can be applied in post processing with an almost opposite
frequency response to perfectly correct the rolloff provided
by the AA filter. At frequencies just below the Nyquist Limit (and
be aware that here are absolutely *no* frequencies above the Limit) the
correction from the Sharpen HP filter is at its highest. The filter
increases noise just as much as it increases desired signal, and
that is why the SNR is worse than it would without the AA filter but
the frequency response will be almost precisely the same.

Of course at lower and lower frequencies there is less and less
correction by the Sharpen filter, and therefore less and less
change to the SNR compared to an image taken without the AA filter.

So, where do I get a high pass filter that works exactly to
counteract the AA filter, and why do other filters provide
better results when the result is inspected visually?

What are you mumbling about?

Isn't it childish to claim you don't understand the English
language?


In any case the reason images are apparently not sharp when
viewed at 100% is because a Bayer Color Filter encoded camera
simply cannot produce a tone transition in less than some number
of pixels, and the larger the demosiacing matrix the higher the
minimum for transition, as well as the more accurate the colors.

Actually, you are wrong here. Intelligent demosaicing
detects borders and doesn't smear them, irrespective of their
size. It's not a simple averaging process.

You simply cannot get a one pixel length tone transition,
without applying a Sharpen HP or USM filter. Yes different
demosaicing algorithms can produce sharper results, but absent
some form of sharpen, there are no truly "sharp" transitions.

What is 'truly "sharp"'? A single hot pixel? An aliased
line?

More childish argument rather than any real attempt at discussion.

Asking for clarification what 'truly "sharp"' does mean to you
is childish?


I see lots of transitions from A to B with just one pixel in
between --- and since I cannot align the camera pixel borders
perfectly with the image ...

Actually, looking at resolution tests, one gets transitions
of 1.5 and less pixels.

No you don't.

http://www.dpreview.com/reviews/samsungnx200/10
http://www.dpreview.com/reviews/sonyslta77/16
http://www.dpreview.com/reviews/sonynex5n/8
http://www.dpreview.com/reviews/sonyslta35/8
http://www.dpreview.com/reviews/olympusepl3/12
http://www.dpreview.com/reviews/sonynexc3/11
http://www.dpreview.com/reviews/olympusep3/14
http://www.dpreview.com/reviews/nikond5100/13
http://www.dpreview.com/reviews/canoneos1100D/11
http://www.dpreview.com/reviews/canoneos600d/11


Of course that isn't really "sharpness", but acutance, and again
it can be increased with either a high pass filter (Sharpen) or
application of Unsharp Mask.

Of course that's really sharpness, as such an averaging process
would reduce or destroy the visibility of e.g. thin parallel
lines, thus reducing resolution drastically.

There is no actual increase in resolution. All that happens
with either USM or an HP filter is that the difference between
existing tone transition edges in increased.

Ah, how exactly do you define 'resolution' and how do you
define MTF?

Standard definitions are fine. You can look them up any time
you want to carry on an adult discussion.

And if you can't, I will not respond again.

Poor little child.

-Wolfgang