Keith_Reeder said:
dufflover said:
I still find it laughable though that in the end, it really really, really, does seem like people are all too happy for Canon to not get their DR up to where the competition is
Which assumes, of course, that - unlike an old, out-of-date, underpowered PC - this supposed lack of DR
actually stops us from getting the results we want.
Which it doesn't...
Canon's priority is DR at the top of the histogram (where it performs very well),
and that suits me just fine.
Let me know when a Nikony sensor can do better than
this from
this, and you might have a point...
You completely misunderstand dynamic range. There is absolutely
no such thing as highlight DR ("DR at the top of the histogram"). That's a complete misnomer. Dynamic range by definition represents the ENTIRE range...from the noise floor to the white point. You increase DR...you INCREASE DR. Period. More DR on the D800 means they have more for the shadows, OR more for the highlights...or...more anywhere else you want to use it. It's a RANGE. You fit the exposure into that range. The D800 has VASTLY more highlight headroom, because your much more free to underexpose, and preserve the highlights, while concurrently being able to lift the shadows, than the 5D III. Conversely, you want to ETTR, mush it right to the limit? You can still do that with the D800...and the shadows become EVEN BETTER.
It's inane notions like highlight DR that seem to have radically confused the Canon community about the capabilities of their cameras. Not only that, based on my own experience, Canon's highlight headroom (yes, headroom...that's the only term that can legitimately be used here...as it does not refer to DR) differs from body to body. The 7D had lots of headroom...when the in-camera JPEGs showed the highlights were clipped via "blinkies", or the histogram starting to ride up the right-hand edge of the histogram, in LR/ACR you were still fully able to recover those highlights. On the flip side, the 5D III's JPEGs seem to represent highlights much more accurately...when they indicate that your clipping or nearly so, it's pretty darn accurate. ETTR too far, and you blow your highlights with a 5D III.
On a D800? LOTS of highlight headroom...when the camera indicates you've blown, you can not only recover...but you can usually recover with a LOT of detail. Detail the 5D III usually doesn't have, as the highlights have at the very least "gone hot"...lost the ability to represent detail and exhibit a loss of color fidelity as they are approaching the clipping point, but not yet actually clipped.
You guys have to stop believing that Canon can improve DR in one area and not another. That's a wild misconception. Dynamic range is dynamic range...there is no such thing as highlight DR or shadow DR. Canon could increase dynamic range by greatly increasing the charge capacity of each pixel (usually, by going to larger pixels). If they do that, the quality of every tonal level increases...dynamic range increases. However, concurrently, they could (and do...this is actually Canon's standard practice) also increase read noise at the same time. While the larger pixels gather more light and that means more DR, they lose a good chunk of that DR to higher read noise. This is EXACTLY the case with the 1D X. Canon designed a BIG sensor with BIG pixels that was capable of gathering nearly 91,000 electrons worth of charge per pixel (quite a bit more than any of their other sensors.) If they had left read noise at the prior 16.6e- levels of the 1D IV, the 1D X would have had 12.45 stops of dynamic range. If they found a way of keeping read noise at the same levels as the 7D, 8.6e-, they would have had a whopping 13.4 stops of DR.
Canon cannot have better highlight DR than a D800 with their current sensor and readout pipeline design. I don't know the specific reasons for it, however Canon's system has very high noise. My suspicion is that it's due to the frequency at which the ADC units and DIGIC chips operate...which continues to increase with each successive generation. Along with the increase in readout frequency comes an increase in read noise (just look through sensorgen.info...Canon read noise wasn't really that bad when you go back to the 400D, 40D, 450D, 5D days). It's spiked with the 1D X, which required a very high readout speed to achieve the 14fps mirror-locked frame rate. It's over 38e- now! Canon loses dynamic range because they have not just high read noise, but exceptionally high read noise. That loss in dynamic range reduces
the range. Therefor, it affects highlights as well as shadows as well as midtones as well as every other usable tonal level in the image.