Entry level Nikon 24mp?!

Eric Stevens wrote:

Four pixels make a Bayer cell.

Only in terms of repeating patterns. Not in terms of resolution
(which is higher). Nor in terms of how demosaicing works (which
needs more pixels).

-Wolfgang

"Eric Stevens" wrote in message
...
On Tue, 10 Apr 2012 19:33:10 +1000, "Trevor" wrote:
"Eric Stevens" wrote in message
news

Says 2.7 Mp total, 2.66 Mp effective. Where do you get a 10.8Mp sensor?

Four pixels make a Bayer cell.

2.7 million Bayer cells = 2.7 x 4 million pixels = 10.8Mp

It all depends on how you define cell and pixel.

You just differentiated them OK. No need to swap and change definitions at
random.

It wasn't me that did it. It goes back to your original question.


No question of mine. It was your claim above of a 10.8M*pixel* sensor (not
cell) however wasn't it?

Trevor.

In article , Eric Stevens
wrote:

Four pixels make a Bayer cell.

no they definitely do not.

2.7 million Bayer cells = 2.7 x 4 million pixels = 10.8Mp

It all depends on how you define cell and pixel.

no it doesn't.

Wrong. :-(

it's not wrong.

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.

actually it was 2.7 mp from a 10.8 mp sensor.
That is absolutely correct.

Fromhttp://imaging.nikon.com/history/scenes/12/

"I guess that it's now safe to reveal that the D1 image
sensor, with specifications noting a pixel count of
2.7-million pixels, actually had a pixel count of 10.8-million
pixels. The technical reason for an actual pixel count four
times greater than that indicated publicly lies in the need to
achieve high sensitivity and a good signal-to-noise ratio.
Unlike current cameras, for which final pixel counts account
for individual pixels, we had to include multiple pixels in
each pixel unit with the D1." -- Kiyoshige Shibazaki, Nikon


Neither of us are right according to
http://www.nikonusa.com/Nikon-Produc...Tabs-TechSpecs


Says 2.7 Mp total, 2.66 Mp effective. Where do you get a 10.8Mp sensor?


Four pixels make a Bayer cell.
Balderdash. The Bayer filter has nothing to do with it. The
RAW file output from the camera is Bayer encoded, and has
2,663,888 pixel data values (2012x1324).

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.
Some Canons have a smaller optional raw format.

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

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.

actually it was 2.7 mp from a 10.8 mp sensor.
That is absolutely correct.

Fromhttp://imaging.nikon.com/history/scenes/12/

"I guess that it's now safe to reveal that the D1 image
sensor, with specifications noting a pixel count of
2.7-million pixels, actually had a pixel count of 10.8-million
pixels. The technical reason for an actual pixel count four
times greater than that indicated publicly lies in the need to
achieve high sensitivity and a good signal-to-noise ratio.
Unlike current cameras, for which final pixel counts account
for individual pixels, we had to include multiple pixels in
each pixel unit with the D1." -- Kiyoshige Shibazaki, Nikon


Neither of us are right according to
http://www.nikonusa.com/Nikon-Produc...Tabs-TechSpecs


Says 2.7 Mp total, 2.66 Mp effective. Where do you get a 10.8Mp sensor?


Four pixels make a Bayer cell.
Balderdash. The Bayer filter has nothing to do with it. The
RAW file output from the camera is Bayer encoded, and has
2,663,888 pixel data values (2012x1324).

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.

Some Canons have a smaller optional raw format.

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

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 removes high frequency detail, and in
that sense reduces sharpness. However, application of
sharpening (in particular USM) to images that have been
downsized certainly increases acutance, or the acuteness of
tonal edges. Some down sizing methods (cubic sharper, as an
example) introduce a certain amount of ringing (haloing) at tone
transitions, which is in effect a sharpening method.

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).

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.
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.

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

On Sat, 14 Apr 2012 22:12:27 +1000, "Trevor" wrote:


"Eric Stevens" wrote in message
.. .
On Tue, 10 Apr 2012 19:33:10 +1000, "Trevor" wrote:
"Eric Stevens" wrote in message
news
Says 2.7 Mp total, 2.66 Mp effective. Where do you get a 10.8Mp sensor?

Four pixels make a Bayer cell.

2.7 million Bayer cells = 2.7 x 4 million pixels = 10.8Mp

It all depends on how you define cell and pixel.

You just differentiated them OK. No need to swap and change definitions at
random.

It wasn't me that did it. It goes back to your original question.


No question of mine. It was your claim above of a 10.8M*pixel* sensor (not
cell) however wasn't it?

Lets start again.

One pixel is a cell collecting light.

One Bayer cell consists of 4 pixels: Red, Blue and 2 x Green.

Some people call a Bayer Cell a pixel. Other people call the basic
light collecting elements 'pixels'.

That four to one ratio is what lies behind my statement to which you
object.

Regards,

Eric Stevens

On Sat, 14 Apr 2012 08:57:47 -0400, nospam
wrote:

In article , Eric Stevens
wrote:

Four pixels make a Bayer cell.

no they definitely do not.

2.7 million Bayer cells = 2.7 x 4 million pixels = 10.8Mp

It all depends on how you define cell and pixel.

no it doesn't.

Wrong. :-(

it's not wrong.

'tis.

Regards,

Eric Stevens

Eric Stevens wrote:
On Sat, 14 Apr 2012 22:12:27 +1000, "Trevor" wrote:


"Eric Stevens" wrote in message
. ..
On Tue, 10 Apr 2012 19:33:10 +1000, "Trevor" wrote:
"Eric Stevens" wrote in message
news
Says 2.7 Mp total, 2.66 Mp effective. Where do you get a 10.8Mp sensor?

Four pixels make a Bayer cell.

2.7 million Bayer cells = 2.7 x 4 million pixels = 10.8Mp

It all depends on how you define cell and pixel.

You just differentiated them OK. No need to swap and change definitions at
random.

It wasn't me that did it. It goes back to your original question.


No question of mine. It was your claim above of a 10.8M*pixel* sensor (not
cell) however wasn't it?

Lets start again.

One pixel is a cell collecting light.

No, one sensor location is the smallest object that collects light.
A pixel is an image element, and that is something that is later
derived from multiple sensor locations. It is true that with a
Bayer CFA encoded sensor there are approximately the same number
of image sensors as there are pixels in the resulting images, but
they are not generated on a one to one basis.

One Bayer cell consists of 4 pixels: Red, Blue and 2 x Green.

One image pixel is derived from a Bayer Matrix made up of at
least (but not limited to) a minimum set of 4 sensor locations.

Some people call a Bayer Cell a pixel. Other people call the basic
light collecting elements 'pixels'.

Both are technically wrong though. But anyone who says a 2x2
Bayer matrix is what constitutes a pixel in itself just doesn't
understand the concept of CFA encoding.

That four to one ratio is what lies behind my statement to which you
object.

He should object, because it just had nothing to do with
reality, and incidentally is totally unrelated to the above
discussion about Bayer matrixes.

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

Eric Stevens wrote:
On Sat, 14 Apr 2012 08:57:47 -0400, nospam
wrote:

In article , Eric Stevens
wrote:

Four pixels make a Bayer cell.

no they definitely do not.

That last line is correct.

2.7 million Bayer cells = 2.7 x 4 million pixels = 10.8Mp

It all depends on how you define cell and pixel.

no it doesn't.

Wrong. :-(

it's not wrong.

'tis.

But *nobody* who understands Bayer CFA encoding defines it the
way you did, so while it might depend of how they are defined,
your premises are wrong to start with.

The Nikon D1 generated a RAW file with data for 2,663,888 sensor
"locations". Some RAW converters generated 2.66 MP images
(2012x1324), but Nikon's generated 2.62 MP images (2000x1312).
The 2.66 MP is commonly rounded to 2.7 MP.

The actual sensor had 4 sensor locations for each data location
generated for the RAW file. Hence 4 * 2.7 = 10.8, but in fact
it was actually 4 * 2,663,888 or 10,655,552 sensor locations.
Regardless, the most pixels that could be generated were
2,663,888 because that was the maximum number of available
sensor data points.

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

On Sat, 14 Apr 2012 02:09:29 -0800, (Floyd L.
Davidson) wrote:

Eric Stevens wrote:
rOn Tue, 10 Apr 2012 17:33:35 +1000, "Trevor" wrote:
"Eric Stevens" wrote:
The Nikon D1 was 2.4 Mp.

actually it was 2.7 mp from a 10.8 mp sensor.

That is absolutely correct.

From http://imaging.nikon.com/history/scenes/12/

"I guess that it's now safe to reveal that the D1 image
sensor, with specifications noting a pixel count of
2.7-million pixels, actually had a pixel count of 10.8-million
pixels. The technical reason for an actual pixel count four
times greater than that indicated publicly lies in the need to
achieve high sensitivity and a good signal-to-noise ratio.
Unlike current cameras, for which final pixel counts account
for individual pixels, we had to include multiple pixels in
each pixel unit with the D1." -- Kiyoshige Shibazaki, Nikon


Neither of us are right according to
http://www.nikonusa.com/Nikon-Produc...Tabs-TechSpecs


Says 2.7 Mp total, 2.66 Mp effective. Where do you get a 10.8Mp sensor?


Four pixels make a Bayer cell.

Balderdash. The Bayer filter has nothing to do with it. The
RAW file output from the camera is Bayer encoded, and has
2,663,888 pixel data values (2012x1324).

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.

2.7 million Bayer cells = 2.7 x 4 million pixels = 10.8Mp

It all depends on how you define cell and pixel.

No it doesn't. First, the idea that a "Bayer cell" is 4 sensor
locations is ignorant. The *minimum* number of sensor locations
used to generate an image pixel is 4 (a 2x2 matrix), but in fact
all but the most basic raw conversion program will use either a
3x3 matrix or a 5x5 matrix. Hence pixels are usually generated
from either 9 sensor locations or 25, not 4.

Regardless the RAW data from the Nikon D1 contained only 2.66
MP. And after the Bayer CFA is decoded Nikon generated a
2000x3012 pixel image (and some raw converters used the entire
2012x3024).

Incidentally, I have a very functional Nikon D1 sitting within
arms reach.

And also, note that the D1X generated pixels by binning two
side by side sensor sites per pixel, rather than 4.

Thanks for all that. It makes sense of what was rapidly growing into a
directionless argument.

I suspect from what you have said that every active light-sensitive
pixel was surrounded by a 'binned' inactive pixel. The result would be
an array of 4 x 4 pixels such as:

X R X G
X X X X
X G X B
X X X X

That would give 4 active pixels for every 16.

These arrays would be stacked to give:

^
|
X R X G X R X G
X X X X X X X X
X G X B X G X B
X X X X X X X X ---
X R X G X R X G
X X X X X X X X
X G X B X G X B
X X X X X X X X

I don't know why they did that, although I can think of a number of
possible reasons.

Regards,

Eric Stevens