I’ve spent a lot of time on signal-to-noise ratio (SNR) studies at mid and higher tones (Zones V through VII). Now it’s time to look at SNRs in the darker areas of the picture. Things get a bit more complicated as things get dimmer. At high photon counts, we can safely say that the mean… [Read More]
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ETTR — just crank up the ISO? Part 8
Here are the SNR graphs from yesterday, but for the D800E instead of the D4. There is even less reason to increase the ISO to improve the SNR of midtone and brighter values than there is on the D4. Note how low the statistical variation is compared to the D4. Why? I don’t know. Should… [Read More]
ETTR — just crank up the ISO? Part 7
I’ve been working on improving the presentation of the SNR versus ISO setting data, and on improving the precision of the data itself. On the latter point, the most effective thing that I’ve done to remove systematic errors is to keep the shutter speeds constant throughout a series of exposures, and make all the required… [Read More]
ETTR — just crank up the ISO? Part 5
I looked at the SNR vs ISO/DIN performance of a couple of Sony cameras. How I made these curves is described here. As before, the way to use these curves is to find the ISO/DIN setting beyond which the Actual (red) line drops as fast as the 1.5 decibel/octave line. Beyond that point, for a… [Read More]
ETTR — just crank up the ISO? Part 4
I’ve refined the calculations behind the graphs in the first post of this series. Specifically, I’ve added normalization to the 1.5 dB/octave lines so that they are corrected for the actual exposure of the test images, as measured by the mean value of the pixels in the selection box. The Poisson-limited lines had already been… [Read More]