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11-04-2014, 01:24 AM   #181
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QuoteOriginally posted by osv Quote
afaik, pixel pitch is a calculated estimation, but it doesn't necessarily represent pixel size.
i'd like to see actual pixel size, if you have it.
You mean like this?



or this, from the D600's sensor:



11-04-2014, 05:00 AM - 2 Likes   #182
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QuoteOriginally posted by rawr Quote
You mean like this?
Well, here we only see the micro-lensed surface. Behind that, things get a bit more complicated:





CMOS Schematics from BroadcastEngineering and



'Real-life' CMOS micro photograph
11-04-2014, 05:07 AM   #183
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I believe the "total light" argument is true when both pictures are enlarged to the same print size...
That's why crops from FF "lose light", you need to enlarge more.
11-04-2014, 06:45 AM   #184
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QuoteOriginally posted by jsherman999 Quote
I think that's a good source too for some things, but know that some folks have some problems with some of his verbage on pixel size. (I think he's amended it some from the early days, perhaps, taking some new thinking into account?) Anyway, take this as a caveat to consider: The problem with Dr Clark's narrative.
.
jsherman999, thanks for the link. It's true that there were uncontrolled assumptions about photon to electron conversion efficiency scaling linearly per unit square area as pixel density changed. Good reading, thanks.

11-04-2014, 08:13 AM   #185
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QuoteOriginally posted by Stone G. Quote
Well, here we only see the micro-lensed surface. Behind that, things get a bit more complicated:





CMOS Schematics from BroadcastEngineering and



'Real-life' CMOS micro photograph
In addition AFAIK each of the 4.8 micron areas shown there is actually really a "sub-pixel", and every real "pixel" mapped into the image is made up of four of those - one red, one blue and two green, and that makes up the Bayer array. But the underlying photodiode is not massive for FF and tiny for smaller sensors, it scales with the size of the microlens, with maybe some variation based on sensor generation. I think the D7000 & D800 were found to be basically the same pixel architecture.
11-04-2014, 08:41 AM   #186
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Meanwhile Sony explains how you can capture the same total light on a much smaller sensor, by eliminating the non-receptive parts of the sensors surface... showing, it's never as simple as you think.

11-04-2014, 09:47 AM   #187
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Yeah, with this new stacked tech seems to be great (but maybe we should take some of the marketing stuff with a grain of salt)
http://www.sony.net/Products/SC-HP/cx_news/vol68/pdf/sideview_vol68.pdf
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11-04-2014, 10:26 AM   #188
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QuoteOriginally posted by Stone G. Quote
Well, here we only see the micro-lensed surface. Behind that, things get a bit more complicated:
exactly my point, thanks

and thanks to everyone else for their input as well.

11-04-2014, 10:28 AM   #189
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QuoteOriginally posted by normhead Quote
Meanwhile Sony explains how you can capture the same total light on a much smaller sensor, by eliminating the non-receptive parts of the sensors surface... showing, it's never as simple as you think.
Still seems pretty simple:

More Light = More Better
Newer Tech = More Better (usually)
More Light + Newer Tech = Most Besterest
11-04-2014, 10:52 AM   #190
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QuoteOriginally posted by jsherman999 Quote
?? The pixel size of almost every sensor is well known, available from multiple sources and derivable if you know the sensor size and # of pixels, and places like chipworks measure it directly with microscopy.

For example, D7000 (and K5) and D800 have almost exactly the same pixel size, about 4.8 microns.
it appears to me that none of that is true, as we see from the diagram of what is under the microlens... you can't calculate pixel pitch, and call it pixel size, and dxo does not publish pixel size measurements.

the dxo comparison there fails, in part because it's different generations of sensor technology, and also because we don't know what the actual pixel size is.

then there is the bsi sensor in the samsung nx1... if you put the nx1 into that dxo diagram of yours, you'd be very wrong about the actual pixel size.

off topic: the nx1 has a pentax adapter :-) if you don't mind losing autofocus.
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11-05-2014, 08:33 AM   #191
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Secret photodiodes!

QuoteOriginally posted by osv Quote
the dxo comparison there fails, in part because it's different generations of sensor technology, and also because we don't know what the actual pixel size is.
?? The K5/D7000 and the D800 are exactly the same sensor generation, and in fact are the same pixel technology from the same design team and coming out of the same fabs at exactly the same time.


QuoteQuote:
it appears to me that none of that is true, as we see from the diagram of what is under the microlens... you can't calculate pixel pitch, and call it pixel size, and dxo does not publish pixel size measurements.
I think it's time for a reality check, here. (I feel like this thread is suffering from a Gish Gallop on this subject right now.)

Your assertion seems to be : under that 4.8 micron microlens, the FF sensor actually has a much larger photodiode than what's under the 4.8 micron microlens on the apsc sensor made at the same time from the same design team and fabricated at the same facility. And this secret size difference under the microlens is why FF images show better noise performance than aps-c of the same generation. It's not total light over a larger sensor area - as the math indicates it would be, not just the measurements - it's secret-size photodiodes. Canon, Sony and Nikon (and whoever else fabs FF sensors) all do this "hiding the bigger diodes under the microlens" trick.

Never mind that Bill Claff and sensorgen (and others) have determined based on raw analysis of the full size images and the 1.5x crops of the FF images vs. the native D7000 aps-c images that the underlying pixel tech is almost exactly the same, down to a single-digit % difference in QE, which equates to less than 1/5 of a stop when the FF image is cropped to 1.5x. Never mind that no-one, Nikon, Sony, chipworks, anyone has claimed that those wafers are fundamentally different in any way. Never mind that anyone can take a 1.5x crop of a D800 image and compare it to a native D7000 image - and try to see any difference (they have, and they couldn't - as expected.)

It's the secret-sized photodiodes, and it always has been.


.

Last edited by jsherman999; 11-05-2014 at 08:47 AM.
11-05-2014, 11:11 AM   #192
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QuoteOriginally posted by jsherman999 Quote
?? The K5/D7000 and the D800 are exactly the same sensor generation, and in fact are the same pixel technology from the same design team and coming out of the same fabs at exactly the same time.
i asked for the actual pixel sizes, and got wrong information in return... does anyone actually know what the real pixel sizes are?? no...

so please pardon my skepticism wrt the unsubstantiated claims that keep showing up in this thread

QuoteOriginally posted by jsherman999 Quote
Your assertion seems to be: ...And this secret size difference under the microlens is why FF images show better noise performance than aps-c of the same generation.
i don't recall ever making any claim about ff vs. crop noise performance in this thread? but i'd like to see actual proof of the correct answer, whatever it is... not just claims that Bill Claff and sensorgen said or did something, but actual links proving the claim.

idle speculation, like we saw with the pixel size claim, is a waste of time.
11-05-2014, 11:17 AM   #193
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Saying ANYTHING on the internet is a waste of time.
11-05-2014, 12:12 PM   #194
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Reading anything on the internet is a waste of time. But when it's about photography, sometimes it's time well wasted.
11-05-2014, 03:37 PM   #195
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QuoteOriginally posted by osv Quote
i don't recall ever making any claim about ff vs. crop noise performance in this thread? but i'd like to see actual proof of the correct answer, whatever it is... not just claims that Bill Claff and sensorgen said or did something, but actual links proving the claim.

.
No, but what you did claim was that FF sees it's image SNR advantage because the pixels were bigger - right?

What I was illustrating was that it still holds an advantage even if the pixels are the same size, demonstrated by the D800 vs D7000 - because the vast majority of the delta between FF and aps-c of the same gen is not about the pixel size, it's about the (drum roll) Total Light. (How about that, I'm staying on-topic with the thread title, not always a guarantee with me )

Anyway - what 'correct answer' are you looking for specifically, the exact sizes of the photodiodes under the microlens? I might be able to find that.
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