Large Sensors and true LiveView

[pcunite]

Now that Canon has developed an 8x8 inch CMOS sensor all we need is for this technology to be made available to us in various sizes. Along with LiveView, which is a given in the CMOS world, this would truly revolutionize high end photography. 35mm will always be around for its nimbleness but 4x5 just got put on Canon's road map.

[BJNY]

Now that Canon has developed an 8x8 inch CMOS sensor all we need is for this technology to be made available to us in various sizes. Along with LiveView, which is a given in the CMOS world, this would truly revolutionize high end photography. 35mm will always be around for its nimbleness but 4x5 just got put on Canon's road map.

Link:  http://www.dpreview.com/news/1008/10083101canonlargestsensor.asp

[PatrikR]

 S...t and I just sold my Sinar P2 8x10.

Canon rules!

[BJNY]

Speculation about global shutter: 

http://www.eoshd.com/content/326-Have-Canon-made-global-shutter-breakthrough-with-experimental-sensor

[Graham Mitchell]

Finally! A Canon thread which actually belongs in this forum 

[ondebanks]

ASTRONOMY! ASTRONOMY! ASTRONOMY!

...was my first heart-pounding reaction on seeing this. That was even before I got to the quote from Canon Japan: "Potential applications for the new high-sensitivity CMOS sensor include the video recording of stars in the night sky and nocturnal animal behavior." Normal video rate astro-imaging is not often useful to the professional astronomer - when we do need high time resolution imaging e.g. for pulsars, we need millisecond or better - but the huge area and sensitivity are. And one benefit of the video rate is that the observing duty cycle, defined as [exposure time / [exposure time + readout time]], will be close to 100% even on brighter objects where it usually suffers in astronomy - as the CCDs are readout slowly (seconds to minutes) to lower the readnoise.

This technology could overtake the giant CCD sensor mosaics being constructed for the likes of the LSST: http://www.lsst.org/lsst/science/concept_camera. Especially if Canon can deliver their trademark low readnoise (much better than CCDs) on a platform that big.

[Dick Roadnight]

When will they make a budget 5 * 5" 10 micron sensor (on a Sinar board) for use with large format film lenses?

[PdF]

<< ASTRONOMY! ASTRONOMY! ASTRONOMY! >>

The price of such a sensor is certainly astronomical.

PdF

[EricWHiss]

Very interesting! 

And yes the price...  would have to be at least 40 times the cost of the 5D2 sensor since that's what they can get from the same wafer. 

[pcunite]

Very interesting! 

And yes the price...  would have to be at least 40 times the cost of the 5D2 sensor since that's what they can get from the same wafer. 

Maybe, but a 4x5 would only be about 20 times, so about $20K... I have no idea, just guessing here of course.

[EricWHiss]

Maybe, but a 4x5 would only be about 20 times, so about $20K... I have no idea, just guessing here of course.

All of it's a gross simplification - who knows what the yield will be, but with bigger chips, they will have to toss a higher percentage that's for sure.  Plus who knows the market and other costs for this one? 
All aside, if they can go big that is super news.  I'm not as keen on a 8x10 as I would be a 56mm x 56mm chip for my Rollei.

[BernardLanguillier]

<< ASTRONOMY! ASTRONOMY! ASTRONOMY! >>

The price of such a sensor is certainly astronomical.

The price of a single piece of silicon that large is still ridiculously cheap, as I mentioned before. We are talking about roughly 50 US$ per 200m wafer... you might need 10 of then to get one perfect one, but even that is doubtful as the processes have been perfected to incredible levels.

So a large sensor might be expensive to product but silicon is a small contributor to the final price of the device, although some vendors have obviously gone to great lenght to make us feel otherwise.

Cheers,
Bernard

[uaiomex]

What a paradox!
Silicon is the most common element on earth.
Eduardo

The price of a single piece of silicon that large is still ridiculously cheap, as I mentioned before. We are talking about roughly 50 US$ per 200m wafer... you might need 10 of then to get one perfect one, but even that is doubtful as the processes have been perfected to incredible levels.

So a large sensor might be expensive to product but silicon is a small contributor to the final price of the device, although some vendors have obviously gone to great lenght to make us feel otherwise.

Cheers,
Bernard

[BernardLanguillier]

What a paradox!
Silicon is the most common element on earth.

I would speak of paradox if these wafers were expensive, but in fact they are not. 

Cheers,
Bernard

[Zerui]

What about the bandwidth limitation for communication between camera back and monitor?
Do we need to replace firewire 8oo with something faster, or is the limitation in the camera computer?
Perhaps Dr Roadknight can enlighten us.
John

[ondebanks]

What about the bandwidth limitation for communication between camera back and monitor?
Do we need to replace firewire 8oo with something faster, or is the limitation in the camera computer?
Perhaps Dr Roadknight can enlighten us.
John

I imagine it would have to be directly connected by fibre channel, like in supercomputers.

[Dick Roadnight]

What about the bandwidth limitation for communication between camera back and monitor?
Do we need to replace firewire 8oo with something faster, or is the limitation in the camera computer?
Perhaps Mr Roadnight can enlighten us.
John

I do not know.

"Bandwidth" means data transfer rate, and it is the data transfer rate between camera and computer that would be of concern.

If you knew the video frames-per-second and file size per frame, and the actual "real world" data transfer rate of firewire 800, it should be simple arithmetic.

The file format for the transfer from back to camera would probably be a compressed raw format similar to Hasselblad's 3FR,,, and then you would have to do similar calculations with the audio signal.

...and I have no PhD or MD, and there is no "k" in my name.

[BJL]

The price of a single piece of silicon that large is still ridiculously cheap, as I mentioned before. We are talking about roughly 50 US$ per 200m wafer ...

The price of the blank wafer is clearly a very small part of the sales price of the sensors made on them. That 200mm wafer would hold about 20 36x24mm sensors, for a silicon cost of about $2.50/sensor, way under 1% of the price of such sensors.

... you might need 10 of then to get one perfect one, but even that is doubtful as the processes have been perfected to incredible levels.

Do you have any basis whatsoever for that one in ten figure? We are talking about needing
1. free of fatal defects over almost the entire wafer, whereas with most chip fab., each defect only causes one of many chips to be rejected.
2. massive stitching; maybe 100 fields or so, and thus greatly increased opportunities for errors there, and complexity (repeated careful alignment after moving the stepper to each new field) in the process.

Given that puny little 44x33mm sensors cost several thousand dollars, and the yield with clearly be lower for this far larger size, we can safely scale by a factor of well over the area ratio (about 30), getting well past $100,000 I would say.

P. S. Dalsa already offers CCD sensors of about this size on a custom basis: the Canon claim is mostly big CMOS. No camera maker has ordered a 5"x4" sensor from Dalsa (or even 6x7 or 6x6 or full 645 size) again hinting that cost is a major barrier.

P. P. S. It is probably 10MP or less, going by the hint that photosite area is 100 times greater than on Canon 22MP, 36x24mm sensor.

[BernardLanguillier]

Do you have any basis whatsoever for that one in ten figure? We are talking about needing
1. free of fatal defects over almost the entire wafer, whereas with most chip fab., each defect only causes one of many chips to be rejected.
2. massive stitching; maybe 100 fields or so, and thus greatly increased opportunities for errors there, and complexity (repeated careful alignment after moving the stepper to each new field) in the process.

Given that puny little 44x33mm sensors cost several thousand dollars, and the yield with clearly be lower for this far larger size, we can safely scale by a factor of well over the area ratio (about 30), getting well past $100,000 I would say.

P. S. Dalsa already offers CCD sensors of about this size on a custom basis: the Canon claim is mostly big CMOS. No camera maker has ordered a 5"x4" sensor from Dalsa (or even 6x7 or 6x6 or full 645 size) again hinting that cost is a major barrier.

Well, your guess is a good as mine regarding how many wafer would be required to produce one of these.

Now that I think aout it, there is almost no cost involved in fact. It would be fairly easy for a company like Canon to identify in advance those perfect wafers and to use these for large chips, while using non perfect wafers for smaller chips. From then on it is just a matter of process control to make sure that at least some wafers are perfect.

This is not a genius idea. Intel does the same with their CPUs. Higher Mhz units are often perfectly identical to lower Mhz ones, they just pass the tests better.

This approach would only cost as much as the process to identify the perfect wafers from the others. A trivial cost amidst a large series.

So my prerogative is that getting perfect 200m wafers suitable to large sensors has basically no cost if you produce enough smaller sensors a year.

As far as stitching is concerned, sensors are pretty low tech devices in terms of lithography, and I don't expect stitching to have particularly low yields even if a large amount of passes are required.

So I am not convinced that all the talk about  large sensor costs is not mostly driven by a marketing urge to sell the resulting products at undeservely high prices. This, again is the same with CPUs, where the very same design rated at a higher Mhz is selling at 3 times the price mostly because we are being told by Intel/AMD it is a better part.

Cheers,
Bernard

[Zerui]

From D.Roadnight   "I have no PhD or MD, and there is no "k" in my name."

Apologies.  I should be more careful first thing in the morning!

John