25 MP sensor of Sony

In article <VU8oj.32445$mT.14080@fe04.news.easynews.com>, Michael J.
Astrauskas says...
> Alfred Molon wrote:
> > In article <fnqr78$rds$1@panix3.panix.com>, Al Dykes says...
> >
> >> I was looking at the 6 frames/sec capability. With 3 bytes/pixel,
> >> that's 450M Bytes/Sec sustained transfer rate and/or a Gigabyte of RAM
> >> in-camera to buffer a burst of two seconds.
> >
> > More likely it's 12 or 14 bit/pixel, not 24 bit.
>
> I think you may mean 12 or 14 bits per channel, so 36 or 42 bits per pixel.

Each pixel in a Bayer sensor only has one channel.
--

Alfred Molon
------------------------------
Olympus 50X0, 8080, E3X0, E4X0, E5X0 and E3 forum at
http://tech.groups.yahoo.com/group/MyOlympus/
http://myolympus.org/ photo sharing site
 >> Stay informed about: 25 MP sensor of Sony 

In article <60co9bF1ppnujU4.RemoveThis@mid.individual.net>, ray says...
> On Wed, 30 Jan 2008 23:42:19 +0100, Alfred Molon wrote:
>
> > In article <60c94eF1qbe81U1.RemoveThis@mid.individual.net>, ray says...
> >
> >> Since the sensor seems to be the same size as a 35mm frame, I would
> >> assume that standard 35mm lenses should be adequate.
> >
> > I have doubts about that. You'll likely need some high quality lens,
> > capable of corner to corner sharpness.
>
> Could you explain why you'd need it more there than with 35mm film - when
> the sensor is the same size?

Because film resolution is much lower than 25MP. But I don't want to
start a debate about this (i.e. how many pixels there are in a film
frame).

In any case you will need a lens with strong MTF at 83 lp/mm (pixels are
6 micrometer), all over the lens frame. If you look at the tests at
http://www.photodo.com/ you'll notice that there are not many lenses
with strong MTF over the entire frame at 83 lp/mm.
--

Alfred Molon
------------------------------
Olympus 50X0, 8080, E3X0, E4X0, E5X0 and E3 forum at
http://tech.groups.yahoo.com/group/MyOlympus/
http://myolympus.org/ photo sharing site
 >> Stay informed about: 25 MP sensor of Sony 

Alfred Molon wrote:
> In article <60c94eF1qbe81U1 DeleteThis @mid.individual.net>, ray says...
>
>> Since the sensor seems to be the same size as a 35mm frame, I would
>> assume that standard 35mm lenses should be adequate.
>
> I have doubts about that. You'll likely need some high quality lens,
> capable of corner to corner sharpness.

It may be better simply to omit the anti-alias filter, and rely on the
sensor over-sampling the inherent resolution of the lens.

David
 >> Stay informed about: 25 MP sensor of Sony 

David J Taylor wrote:
> Alfred Molon wrote:
>> ray says...
>>
>>> Since the sensor seems to be the same size as a 35mm frame, I would
>>> assume that standard 35mm lenses should be adequate.

>> I have doubts about that. You'll likely need some high quality lens,
>> capable of corner to corner sharpness.
>
> It may be better simply to omit the anti-alias filter, and rely on the
> sensor over-sampling the inherent resolution of the lens.

That makes some sense, but, near as I can tell, it turns into a
really hard optical problem. "Sharpness" and "resolution" do not
describe the same thing. Limited resolution is not a good
anti-alias filter.


There is a case for designing digital lenses differently from
traditional film-photography lenses. Geometric distortion is
correctable. Lateral chromatic aberration is mostly-correctable.
Lens design is largely a matter of trade-offs, and the move to
digital substantially changes the cost of many of the trade
items.


--
--Bryan
 >> Stay informed about: 25 MP sensor of Sony 

Chris Malcolm <cam DeleteThis @holyrood.ed.ac.uk> wrote:
>Floyd L. Davidson <floyd DeleteThis @apaflo.com> wrote:
>> If the bits needed to cover the cell's dynamic range are
>> not there, whatever range of bright to dark the cell can
>> capture is *lost*. It *is* exactly the issue. One cell
>> may be at it's brightest, and another cell at it's
>> darkest... they *both* must be encoded in the digital
>> signal.
>
>They can be encoded with any number of bits from 1 upwards. You don't
>lose dynamic range with fewer bits, you lose fineness of gradation
>steps.

Sure, all you need to do is ignore reality. The fact is
that we *are* talking about a linear raw data stream,
where each step as twice the value of the previous one.
There is no gamma correction applied to the analog data.

While with some other form of data it is possible to
record a wide dynamic range in 1 bit, it is not possible
to do so without generating a huge amount of
quantization distortion.

>With one bit all you get is white and black.

And virtually *no* signal to noise ratio, because the
quantization distortion is as large as the signal.

The point of course is that we are discussing a specific
type of data, and your discussion does not apply.

>With four bits you
>get two intermediate shades of grey. With 12 bits you get 4000 shades
>of grey. I'm pretty sure I can't distinguish 4,000 different shades of
>grey, so I'm sure 12 bits is more than enough for the dynamic range of
>my eyes, other things being equal.

That isn't true though. With 12 bits what you get is
2048 values in the top fstop, but you still get only 2
values in the lowest fstop. The significant point is
how far appart those are, in fstops. (Actually, the
significance is how far the fstop that has 8 values is
from the brightest fstop, which is the "useful dynamic
range".)

12 bits does not come close to equal the range your eyes
can handle.

>There's no reason why a 10bit ADC
>couldn;t cover 10 times the dynamic range of a 15 bit ADC.

Wrong. Signal to Noise Ratio is the reason.

>However,
>it's often technologically convenient to use more bits than necessary
>for a variety of reasons, and those reasons change with the
>technology.

So just show us a case where that is being used by a
DSLR today. (It is very common for digital applications
using voice frequencies, such as telephones and modems.
It is not common, yet, with DSLR's.)

>Given Sony's different implementation of the ADCs their 12 bits might
>in fact offer less noise and more dynamic range than the usual 14
>bits, just as X's 12MP camera might offer higher resolution images
>than Y's 13MP camera. It's not just the numbers.

That's nonsense.

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd DeleteThis @apaflo.com
 >> Stay informed about: 25 MP sensor of Sony 

"Michael J. Astrauskas" <trevie.RemoveThis@nospam.cox.net> wrote in message
news:VU8oj.32445$mT.14080@fe04.news.easynews.com...
> Alfred Molon wrote:
>> In article <fnqr78$rds$1@panix3.panix.com>, Al Dykes says...
>>
>>> I was looking at the 6 frames/sec capability. With 3 bytes/pixel,
>>> that's 450M Bytes/Sec sustained transfer rate and/or a Gigabyte of RAM
>>> in-camera to buffer a burst of two seconds.
>>
>> More likely it's 12 or 14 bit/pixel, not 24 bit.
>
> I think you may mean 12 or 14 bits per channel, so 36 or 42 bits per
> pixel.

All you have to buffer is the raw data, so it's only 12 or 14 bits per
pixel.

This is where 3-color perpixel sensors are problematic: the raw files are
three times larger.

David J. Littleboy
Tokyo, Japan
 >> Stay informed about: 25 MP sensor of Sony 

Ali wrote:
> Maybe I am wrong, but there is no substance to this press release.
>
> They have only announced the development of the 25mp full frame sensor.
> There is no physical product yet.
>
Then it could be a good relief to them, if their engineers/designers
ever bother to read ng, that a full-frame chip, intended for high-end
cameras, should have at least 14 bit d/a converter, not 12 bit as in
their press release. They can now go back and get it right. All new
high end cameras from Canon and Nikon have 14 bit.
 >> Stay informed about: 25 MP sensor of Sony 

frederick wrote:
> Ali wrote:
>> Maybe I am wrong, but there is no substance to this press release.
>>
>> They have only announced the development of the 25mp full frame
>> sensor. There is no physical product yet.
>>
> Then it could be a good relief to them, if their engineers/designers
> ever bother to read ng, that a full-frame chip, intended for high-end
> cameras, should have at least 14 bit d/a converter, not 12 bit as in
> their press release. They can now go back and get it right. All new
> high end cameras from Canon and Nikon have 14 bit.

"Sony's "Column-Parallel A/D Conversion Technique" also provides each
column within the sensor with its own A/D converter, minimizing image
degradation caused by the noise that arises during analog processing
while at the same time delivering an extremely high signal conversion
speed."

but this quote sounds like it's more of a marketing hype move and may
not materialize:

"In recent years, the demand for digital SLR cameras featuring high
resolution and wide graduation ranges capable of capturing every detail
of the subject matter has continued to increase, particularly among
high-end amateur users."

There isn't much of an amateur market for $7,000 cameras, maybe for
$2,500 cameras made by companies "capable of making $7,000 cameras".
 >> Stay informed about: 25 MP sensor of Sony 

In article <1201732332.929277@ftpsrv1>, frederick <lost DeleteThis @sea.com> wrote:

> Ali wrote:
> > Maybe I am wrong, but there is no substance to this press release.
> >
> > They have only announced the development of the 25mp full frame sensor.
> > There is no physical product yet.
> >
> Then it could be a good relief to them, if their engineers/designers
> ever bother to read ng, that a full-frame chip, intended for high-end
> cameras, should have at least 14 bit d/a converter, not 12 bit as in
> their press release. They can now go back and get it right. All new
> high end cameras from Canon and Nikon have 14 bit.

The need for levels per pixel goes down as the resolution goes up.
Don't forget that even really good printers may have only 1 to 3 bits
per ink. 25mp is 318 ppi on a 13" x 19" print. You're doing it wrong
if 12 bits per pixel at 318 ppi starts to posterize.

--
I don't read Google's spam. Reply with another service.
 >> Stay informed about: 25 MP sensor of Sony 

Alfred Molon wrote:
> http://news.sel.sony.com/en/press_room/corporate_news/release/33192.html
>
> What lens would you need for a beast like this? Probably something
> better than a 100 Euro kit lens, right?
That one?
http://adsabs.harvard.edu/abs/1983SPIE..399..418A
Laszlo
 >> Stay informed about: 25 MP sensor of Sony 

"ray" <ray.RemoveThis@zianet.com> wrote:
> On Wed, 30 Jan 2008 23:42:19 +0100, Alfred Molon wrote:
>
>> In article <60c94eF1qbe81U1.RemoveThis@mid.individual.net>, ray says...
>>
>>> Since the sensor seems to be the same size as a 35mm frame, I would
>>> assume that standard 35mm lenses should be adequate.
>>
>> I have doubts about that. You'll likely need some high quality lens,
>> capable of corner to corner sharpness.
>
> Could you explain why you'd need it more there than with 35mm film - when
> the sensor is the same size?

With a 12.7MP FF sensor, when you print at 12x18, the 5D produces images
that are sharper and more detailed than 35mm film can even dream of. A 24MP
sensor would be 4000 x 6000 pixels, and you'd like similar quality prints at
16 x 24. But that's an enormous enlargement from the image projected on the
sensor, and creating a projected image sharp enough to withstand that
enlargement is very difficult.

David J. Littleboy
Tokyo, Japan
 >> Stay informed about: 25 MP sensor of Sony 

"Paul Furman" <paul- RemoveThis @-edgehill.net> wrote:
>>>
>> Then it could be a good relief to them, if their engineers/designers ever
>> bother to read ng, that a full-frame chip, intended for high-end cameras,
>> should have at least 14 bit d/a converter, not 12 bit as in their press
>> release. They can now go back and get it right. All new high end cameras
>> from Canon and Nikon have 14 bit.
>
> "Sony’s “Column-Parallel A/D Conversion Technique” also provides each
> column within the sensor with its own A/D converter, minimizing image
> degradation caused by the noise that arises during analog processing while
> at the same time delivering an extremely high signal conversion speed."
>
> but this quote sounds like it's more of a marketing hype move and may not
> materialize:

Actually, it's not marketing hype, although it's not quite correct. It turns
out that separate A/D converters that run at the speeds required in dSLRs
have analog noise problems, and the 14-bit converters aren't providing any
better performance than the 12-bit converters. Also, at 12MP FF, there's a
real need for more than 12 bits, but at 24MP, there isn't; a clean 12-bit
conversion that provided 10 bits of valid data would be as good as any
current dSLR. (Or at least that's my understanding of Roger Clark's
comments.) It's pretty unlikely they could keep the noise under 1 LSB, so 11
bits of valid data probably isn't possible.

So, _if it works_, Sony's idea of providing large numbers of much slower A/D
converters is a very good idea.

> "In recent years, the demand for digital SLR cameras featuring high
> resolution and wide graduation ranges capable of capturing every detail of
> the subject matter has continued to increase, particularly among high-end
> amateur users."
>
> There isn't much of an amateur market for $7,000 cameras, maybe for $2,500
> cameras made by companies "capable of making $7,000 cameras".

The 5D is real sweet at ISO 200. Very clean images that can take gross
amounts of sharpening without a hint of noise appearing. If Sony can provide
ISO 100 images that are as good or better than 5D ISO 200 images, it'll be
flipping amazing. (At ISO 200, shot noise would raise its ugly head.)
Especially if they can persuade Zeiss to re-release the 21/2.8 Distagon.

David J. Littleboy
Tokyo, Japan
 >> Stay informed about: 25 MP sensor of Sony 

Alfred Molon wrote:
> In article <60co9bF1ppnujU4.DeleteThis@mid.individual.net>, ray says...
>> On Wed, 30 Jan 2008 23:42:19 +0100, Alfred Molon wrote:
>>
>>> In article <60c94eF1qbe81U1.DeleteThis@mid.individual.net>, ray says...
>>>
>>>> Since the sensor seems to be the same size as a 35mm frame, I would
>>>> assume that standard 35mm lenses should be adequate.
>>>
>>> I have doubts about that. You'll likely need some high quality lens,
>>> capable of corner to corner sharpness.
>> Could you explain why you'd need it more there than with 35mm film - when
>> the sensor is the same size?
>
> Because film resolution is much lower than 25MP. But I don't want to
> start a debate about this (i.e. how many pixels there are in a film
> frame).
>
> In any case you will need a lens with strong MTF at 83 lp/mm (pixels are
> 6 micrometer), all over the lens frame. If you look at the tests at
> http://www.photodo.com/ you'll notice that there are not many lenses
> with strong MTF over the entire frame at 83 lp/mm.

They don't seem to show lp/mm, some other unit?

I little google showed 320 lp/mm possible (though 10-80 is more common):

http://www.zeiss.com/c12567a8003b58b9/Contents-Frame/024b91f46d590a3fc...711c006
"The best we had ever achieved before with any SLR lenses was 250 lp/mm.

The new Planar T* 1.4/85 ZF achieved that same resolution at f/5.6, and
even down to f/2.

The new Planar T* 1,4/50 ZF went even further: It reached 320 lp/mm in
the aperture range from f/5.6 to f/2.8, and 250 lp/mm at f/2."
 >> Stay informed about: 25 MP sensor of Sony