6DII Sensor: Estimated high ISO IQ advantage over 5DIV?
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pedro said:
My guess is 2-5 percent better, a difference that can not be reliably detected by pixel peeking.....
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pedro said:
As has been the case for pretty much every camera built since the turn of the century, pixel count has precisely sweet FA to do with low light IQ, and indeed all of the available evidence indicates that higher pixel count = better high ISO performance.
I see the truth of this every day.
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pedro said:
Hi Pedro,
Imagine two FF cameras, one 10Mpixels and the other 40Mpixels....
Both sensors are built on the same fabrication line with the same technology....
In low light photography, the 10Mp pixels receive 4 times the amount of light PER PIXEL as the 40Mp sensor does, and those individual pixels should have 2 stops more DR than the 40Mp pixels.... However, keep in mind that if you resample the 40Mp image down to 10Mp, you will regain those two stops and the two images should be equal. Ultimately, your limitation is the number of photons that you can capture, and with the same total sensor area, both the 10Mp and 40Mp sensors will capture the same amount of light and therefore, should have equal performance...
HOWEVER! there are a few flies in the ointment. With the higher Mp image, you have more detail and by selecting how much you wish to resample, you can choose a tradeoff between DR and resolution of the final image..... but if you resample BOTH images to a lower than 10Mp resolution, this advantage goes away. As a result, this makes the high Mp image more versatile and therefore better....
The next fly (actually two flies) in the ointment are wasted space and edges. There is an amount of wasted space around the edge of each pixel. This wasted space does not capture photons that hit it, and therefore performance is lost. With smaller pixels, you have a greater percentage of wasted space on the sensor and thereby, a bit worse performance. This is counteracted by microlenses which attempt to focus the light away from the edges of the pixels. It helps the problem, but does not cure it. As a result, smaller Mp count sensors are more efficient and capture more light. That said, the difference between 30 and 26 Mp is going to be so slight that you will probably not be able to see it, short of putting the camera onto a calibrated test bench...
The next fly is A/D speed. With a smaller Mp count, you can run the A/D slower and that gives you a bit better accuracy and a bit less noise... but once again, the difference between 30 and 26 Mp is going to be so slight that you will probably not be able to see it, short of putting the camera onto a calibrated test bench...
The last fly is heat. Smaller Mp count = less circuitry = less heat, and once again the difference between 30 and 26 Mp is going to be so slight that you will probably not be able to see it even if you do put the camera onto a calibrated test bench...
As said earlier, I expect the 26Mp sensor to be 2 to 5 percent better, and most likely closer to the 2. Pixel peeping should not be able to detect a difference.
To sum up, it really does not matter.
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I agree with what is being said here, especially by Don Haines.
That said, if I'm not mistaken, the 6D was an improvement in some ways (dynamic range?) over the 5D III and 1D X because it came later and had some improved technology. I'm cautiously hopeful that this will happen again, but I wouldn't hold my breath on high ISO improvements.
That said, if I'm not mistaken, the 6D was an improvement in some ways (dynamic range?) over the 5D III and 1D X because it came later and had some improved technology. I'm cautiously hopeful that this will happen again, but I wouldn't hold my breath on high ISO improvements.
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Also don't forget the importance of the bayer filter and associated color resolution meaning a 40mpx image sampled down to a 10mpx image is going to give a more accurate color representation than a native 10mpx sensor.
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The original 6D was indeed better in both DR, and high ISO than the 5D III. Not by much, but by noticibly. Maybe its just me, but after having been used 1D X (og) for a while, I have the perception that my former 6D also had slightly better colors than the 1D X (falling short to 1DX in High ISO however).pedro said:
So your expectations make sense in a way. However, something tells me that this time we won't see as much difference between the latest generation of 6D and 5D cameras as before.
I must admit though I can't wait to see the first raw samples out of 6D II to check how it improved over a generation.
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pedro said:
the 6D was quieter than the 5DIII because, IMHO as a Radio research & development engineer, it had GPS, which means it HAD to be quieter EMC wise.
The 6D & 5DIII both had seperate ADCs making them vulnerable to radio pickup, the "radio quiet" 6D therefore had an advantage in banding and other noise pickup.
The 5DIV and 6DII is/will be both on chip ADC, I am expecting no difference in this aspect of performance this time as neither is/will be anything like as senstive to pickup.
So it's just a pixels debate. Now that readout noise is down to sub 2e at high ISO (and increasingly at low ISO too) noise is dominated by shot noise in the detected signal.
I'm betting a 5DIV image down sampled to 26Mpix will be equal to the 6DII in all but the very darkest images.
HOWEVER..
If the 6DII is "only" 1080p 60fps capable, then the output ADCs won't need as much bandwidth as the 5DIVs ADCs which are 1080p 120fps capable.. this could reduce readout noise on the 6DII vs the 5DIV assuming both have the same number of ADCs, and so the 6D could be quieter meaning deep shadows on high ISO images could be a little cleaner.
We'll have to wait and see.
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Answer to OP: Subtle, if any.
But if I get more photos in focus because of faster, more accurate AF, then I get more choices and can overcome that subtle difference in post.
The 6DII will be a great camera. The 5DIV is a great camera.
Enjoy either one!
But if I get more photos in focus because of faster, more accurate AF, then I get more choices and can overcome that subtle difference in post.
The 6DII will be a great camera. The 5DIV is a great camera.
Enjoy either one!
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AlanF said:
Errrr... I didn't do this for you, Alan - I assume Sanj isn't a Brit, and he asked what I meant.
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Don Haines said:
Thank you for such a nice summary!! The other unknown is of course the tech. As another brand new sensor and almost a year later, it will be interesting to see how that influences it as well. Maybe I have wishful thinking but straight out of the camera and without resizing (which can have some issues of its own) I am hoping for a 15-20% difference in better iso.
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The biggest factors in comparing two FF sensors would be the quantum efficiency (percentage of photons converted to electrons) and the read noise. The two sensors are too close together in time and (presumably) technology for there to be a detectable difference....Silverstream said:
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