Sony mass-produces back-illuminated image sensors

Kevin McMurtrie wrote:
In article ,
Alfred Molon wrote:

http://www.imaging-resource.com/NEWS/1213308645.html


This is the key sentence:
"The newly developed CMOS image sensor achieves a signal-to-noise
ratio of +8dB(+6dB sensitivity, -2dB noise) in comparison to existing
Sony CMOS image sensors of the same pixel size."

This is good news for cell phones and cheap cameras but, if ever
applied, won't have such an impressive impact on large sensors.

Why do you say that? Isn't the quantum efficiency improvement in going
from front- to back-illumination enough to produce a substantial
sensitivity gain?

David

David J Taylor wrote:
Kevin McMurtrie wrote:
In article ,
Alfred Molon wrote:

http://www.imaging-resource.com/NEWS/1213308645.html


This is the key sentence:
"The newly developed CMOS image sensor achieves a signal-to-noise
ratio of +8dB(+6dB sensitivity, -2dB noise) in comparison to existing
Sony CMOS image sensors of the same pixel size."

This is good news for cell phones and cheap cameras but, if ever
applied, won't have such an impressive impact on large sensors.

Why do you say that? Isn't the quantum efficiency improvement in going
from front- to back-illumination enough to produce a substantial
sensitivity gain?

Why would it be?

No, I don't take their marketing BS as fact.

--
Ray Fischer

Ray Fischer wrote:
David J Taylor
[]
Why do you say that? Isn't the quantum efficiency improvement in
going from front- to back-illumination enough to produce a
substantial sensitivity gain?

Why would it be?

No, I don't take their marketing BS as fact.

As I understand it, the QE difference is a factor of two or three.

David

Paul Furman wrote:
frederick wrote:
Paul Furman wrote:
frederick wrote:
ASAAR wrote:
On Sun, 15 Jun 2008 00:01:21 +1200, frederick wrote:

They mention a 1.7um square pixel size. At 6mp, that extrapolates
to a sensor about 40 x 26mm, a "1/3.6" perhaps.

Typo? A 1/3.6" sensor's dimensions are about 3mm x 4mm. Your
40mm x 26mm sensor would be slightly larger than Full Frame (FX).

Yes - please call it a typo. It sounds better than dumb error ;-0.

It is 5mp, not 6mp so 2592 x 1944 * 1.7 =
4.4 x 3.3

Unsure of working with microns, I checked:
http://www.clarkvision.com/imagedeta...l.size.matter/
"small sensor, 2.3 micron pixel pitch, Canon S70 point and shoot
consumer camera is compared to that from a large sensor, 8.2 micron
pixel pitch, Canon 1D Mark II DSLR"

So 1.7 microns is a very small pixel.

I took 1.7um square as meaning 1.7 square um.

Ah! but still...
The square root of 1.7 is an even smaller 1.3 so a 3.4mm x 2.5mm sensor.

Yeah - somehow I was thinking 6mp, I wrote 6mp above, but the article
does indeed say 5mp.

Reason for that is that press releases are written by people in
marketing departments.

Or targeted to commercial cell phone designers.

Even a sensor that size would be huge for a cellphone camera wouldn't it?

David J Taylor wrote:
Ray Fischer wrote:
David J Taylor
[]
Why do you say that? Isn't the quantum efficiency improvement in
going from front- to back-illumination enough to produce a
substantial sensitivity gain?
Why would it be?

No, I don't take their marketing BS as fact.

As I understand it, the QE difference is a factor of two or three.

David

% of photosite surface obscured by wires / transistors would be
proportionately much less for larger sensels. That's not to say there
mightn't be some benefit.
But photosite size might not be a good indicator or efficiency in any
case. Doesn't seem to correlate with dslr sensor performance.

frederick wrote:
David J Taylor wrote:
Ray Fischer wrote:
David J Taylor
[]
Why do you say that? Isn't the quantum efficiency improvement in
going from front- to back-illumination enough to produce a
substantial sensitivity gain?
Why would it be?

No, I don't take their marketing BS as fact.

As I understand it, the QE difference is a factor of two or three.

David

% of photosite surface obscured by wires / transistors would be
proportionately much less for larger sensels. That's not to say there
mightn't be some benefit.
But photosite size might not be a good indicator or efficiency in any
case. Doesn't seem to correlate with dslr sensor performance.

Thanks, Frederick. I take your point. It will be interesting to see how
it pans out, and whether their technique is applicable to DSLRs.

Cheers,
David

frederick wrote:
Paul Furman wrote:
frederick wrote:
Paul Furman wrote:
frederick wrote:
ASAAR wrote:
On Sun, 15 Jun 2008 00:01:21 +1200, frederick wrote:

They mention a 1.7um square pixel size. At 6mp, that
extrapolates to a sensor about 40 x 26mm, a "1/3.6" perhaps.

Typo? A 1/3.6" sensor's dimensions are about 3mm x 4mm. Your
40mm x 26mm sensor would be slightly larger than Full Frame (FX).

Yes - please call it a typo. It sounds better than dumb error ;-0.

It is 5mp, not 6mp so 2592 x 1944 * 1.7 =
4.4 x 3.3

Unsure of working with microns, I checked:
http://www.clarkvision.com/imagedeta...l.size.matter/
"small sensor, 2.3 micron pixel pitch, Canon S70 point and shoot
consumer camera is compared to that from a large sensor, 8.2 micron
pixel pitch, Canon 1D Mark II DSLR"

So 1.7 microns is a very small pixel.

I took 1.7um square as meaning 1.7 square um.

Ah! but still...
The square root of 1.7 is an even smaller 1.3 so a 3.4mm x 2.5mm sensor.

Yeah - somehow I was thinking 6mp, I wrote 6mp above, but the article
does indeed say 5mp.

Reason for that is that press releases are written by people in
marketing departments.

Or targeted to commercial cell phone designers.

Even a sensor that size would be huge for a cellphone camera wouldn't it?

I think it's a bit on the small side, or maybe average.

--
Paul Furman
www.edgehill.net
www.baynatives.com

all google groups messages filtered due to spam

In article ,
"David J Taylor"
wrote:

Kevin McMurtrie wrote:
In article ,
Alfred Molon wrote:

http://www.imaging-resource.com/NEWS/1213308645.html


This is the key sentence:
"The newly developed CMOS image sensor achieves a signal-to-noise
ratio of +8dB(+6dB sensitivity, -2dB noise) in comparison to existing
Sony CMOS image sensors of the same pixel size."

This is good news for cell phones and cheap cameras but, if ever
applied, won't have such an impressive impact on large sensors.

Why do you say that? Isn't the quantum efficiency improvement in going
from front- to back-illumination enough to produce a substantial
sensitivity gain?

David

The wires block proportionately less light as the sensors get larger.
The meaning of this improvement has to take into account how terrible
Sony's small sensors are.

--
I will not see your reply if you use Google.