p.9 #4 · D800 spanked the 5DIII in every DXO category!
So all this begs the question...what happens differently with the Canon 5D Mark III? If shot at base ISO, it apparently shows terrible banding and noise with a push of the shadows (to the degree that would be equivalent to shooting at high ISO's) versus shooting it at a high ISO where the banding and noise is not an issue. Perhaps the difference in this case is down to very good, in camera (on sensor/chip) noise reduction which kicks in at higher ISO's, even with raws, and or better analog amplification?
p.9 #5 · D800 spanked the 5DIII in every DXO category!
AhamB wrote:
Really? I thought most DSLRs (esp. in the bracket of the D800) have analog gain up to ISO 1600. ISO 6400 would make for only 2 stops underexposure then.
Most non-EXMOR sensors (as in, e.g., all Canon's sensors) have analog gain up to somewhere around 1600. As has been repeatedly demonstrated, Sony EXMOR sensors (D7000, D800) are different.
p.9 #6 · D800 spanked the 5DIII in every DXO category!
AhamB wrote:
Really? I thought most DSLRs (esp. in the bracket of the D800) have analog gain up to ISO 1600. ISO 6400 would make for only 2 stops underexposure then.
I'll show an example below but it's only tangential to my point. My point is ISO has never been a component of exposure. Exposure is the amount of light you allow to reach the sensor, which can only be controlled by the aperture and shutter speed. The fact that most sensors perform better for low exposures by using analog gain and its related ADC optimizations vs only pushing the exposure digitally is just a temporary technical limitation, one which forces most to use a Higher ISO at the time of shooting and accept its consequences such as lower DR, overexposure from too much gain applied, etc... As such, High nominal ISO has no more photographic legitimacy in terms of "proper exposure" than shooting at a lower ISO that is pushed digitally; it's simply done because present technical limitations require it. That changes with Exmor to a large extent. It's a paradigm shift but one that will require some to be "pushed" kicking and screaming
p.9 #8 · D800 spanked the 5DIII in every DXO category!
Tariq Gibran wrote:
So all this begs the question...what happens differently with the Canon 5D Mark III? If shot at base ISO, it apparently shows terrible banding and noise with a push of the shadows (to the degree that would be equivalent to shooting at high ISO's) versus shooting it at a high ISO where the banding and noise is not an issue. Perhaps the difference in this case is down to very good, in camera (on sensor/chip) noise reduction which kicks in at higher ISO's, even with raws, and or better analog amplification?
Canon has been using the same basic CMOS sensor design for a while, whereas Sony introduced a very cutting edge design with EXMOR that uses column-parallel A/D conversion on the actual chip itself.
p.9 #9 · D800 spanked the 5DIII in every DXO category!
snapsy wrote:
I'll show an example below but it's only tangential to my point. My point is ISO has never been a component of exposure. Exposure is the amount of light you allow to reach the sensor, which can only be controlled by the aperture and shutter speed. The fact that most sensors perform better for low exposures by using analog gain and its related ADC optimizations vs only pushing the exposure digitally is just a temporary technical limitation, one which forces most to use a Higher ISO at the time of shooting and accept its consequences such as lower DR, overexposure from too much gain applied, etc... As such, High nominal ISO has no more photographic legitimacy in terms of "proper exposure" than shooting at a lower ISO that is pushed digitally; it's simply done because present technical limitations require it. That changes with Exmor to a large extent. It's a paradigm shift but one that will require some to be "pushed" kicking and screaming
Exactly. ISO in digital cameras is independent of exposure. Cranking ISO is just boosting the signal after exposure, whether it be analog or digital, just like upping exposure in the raw converter is boosting the signal after the fact, too. Of course, the best combination of analog in-camera gain, digital in-camera gain and digital raw converter gain depends on the camera being used and the raw converter being used.
p.9 #10 · D800 spanked the 5DIII in every DXO category!
douglasf13 wrote:
Exactly. ISO in digital cameras is independent of exposure. Cranking ISO is just boosting the signal after exposure, whether it be analog or digital, just like upping exposure in the raw converter is boosting the signal after the fact, too. Of course, the best combination of analog in-camera gain, digital in-camera gain and digital raw converter gain depends on the camera being used and the raw converter being used.
But here you're talking Sony sensors only, right? Canons are digital too but not capable of ISO-less shooting.
While Canons deal pretty good with high ISO (eg comparing 5D2 to D700) theyre much more sensitive to a reasonably correct exposure while the Sonys (=newer Nikons here) are not.
p.9 #11 · D800 spanked the 5DIII in every DXO category!
douglasf13 wrote:
Canon has been using the same basic CMOS sensor design for a while, whereas Sony introduced a very cutting edge design with EXMOR that uses column-parallel A/D conversion on the actual chip itself.
Yes, with parallel column ADC's they can read the sensor out quicker with a slower frequency for the ADC's which reduces the read noise and noise contaminating the analog sections. This also allows them to reduce the area in each pixel devoted to analog noise reduction which increases the light gathering of each pixel, better low-light sensitivity. They also mention in some literature that with the fast readout they can expand DR by doing shorter exposure read followed by the normal exposure read to and doing combining. Not sure if this is done in their current DSLR camera EXMOR sensors or just video sensors.
What I don't understand is the Nikon implementation of LiveView for the D800 and why they had to resort to interpolating lines and with the slight lag when they have a sensor with fast parallel columns ADC's?
Also, what is keeping Canon from going to this basic new arch/paradigm for sensors.
p.9 #13 · D800 spanked the 5DIII in every DXO category!
wfrank wrote:
But here you're talking Sony sensors only, right? Canons are digital too but not capable of ISO-less shooting.
While Canons deal pretty good with high ISO (eg comparing 5D2 to D700) theyre much more sensitive to a reasonably correct exposure while the Sonys (=newer Nikons here) are not.
Exposure is independent of ISO with any digital camera, but, yes, the method of boosting exposure after the fact, whether it be with the camera ISOs or the raw converter exposure slider, depends on the camera.
p.9 #14 · D800 spanked the 5DIII in every DXO category!
Anybody, know why the D800 LiveView is implemented the way it is with the interpolating every other line with lag? Is it because of not enough pixel processing pipeline throughput?
p.9 #15 · D800 spanked the 5DIII in every DXO category!
wayne seltzer wrote:
Anybody, know why the D800 LiveView is implemented the way it is with the interpolating every other line with lag? Is it because of not enough pixel processing pipeline throughput?
