DSPographer

I was thinking of starting with the test subject at 45 degrees. What frequency range is resolvable is different than for vertical bars, which is why I think it would be a good complement to the...

Marianne, Could you provide near 45 degree test bars as well? I expect that the aliasing artifacts could be significantly different than for the vertical bar case.

Marianne, Many of the effects that blur an image can be combined incoherently by just convolving their respective PSF. But, for the optical effects that occur before the anti-aliasing filter that...

It doesn't matter how finely the DXOmark data is plotted when computing a fit. That is because their plot is just a mathematical curve generated from their estimates for read noise, photon gain,...

There is something wrong with sensorgen's numbers. He is attempting to fit DXOmark's data, but somehow comes up with different values than I do. My fit to DXOmark's data is exact- which shows that...

The D800(E) sensor is not ISOless. If it was, then we would see the DXOmark dynamic range plot drop by 1 Ev for each stop increase in ISO. In fact it drops only about 1/2 Ev from 100 to 200 ISO and...

I recall that DXO said they used just the green channel for SNR measurements.

Yes, I proposed a gamma=2 compressed raw standard above that would retain all the counts that you would need for the tonal response given a read noise of zero. The extra counts below the read noise...

As gollywop pointed out, this is backwards. What is intended is that standard deviation of x is greater than one count for all x. Knowing what was intended, I didn't even notice the reversal.

Yes, for a reasonable definition of tonal response we should include the effect of PRNU: as DXO does.But, in my formula I was most concerned with an encoding to capture all the valid raw data-...

I think the definition of signal for a DXOmark SNR is just the mean value of the count at the illumination needed for that mean value. Their noise definition includes read noise, shot noise, and...

The standard deviation of xis less than1 A-D converter count (the LSB value)For all x

You are right. I was calculating the number of levels needed based on read noise and shot noise: without considering the effect of the input A-D quantization noise.I think that in most enthusiast...

To remove the most hot pixels with the hot pixel mapping; heat the sensor first using live view. then do the manual sensor clean for a few seconds. Here is a post with some more...

You just need to step back a few years for global shutter in still cameras. Nikon had it a long time ago. They eliminated the circuitry for it because the negatives outweigh the positives. Notice...

You hint that you didn't propery control the exposure between the cameras which would completely invalidate your results.

Iliah Borg and rhlpetrus did some multiple exposure experiments some time ago of high DR images with normal areas of outside-the-window highlights against inside shadow regions. I think their...

Theoretically, you can get 20 stops of DR on the image plane. The key points are that the level of veiling flare depends on the highlight spot size; and that the noise floor from flare is...

As an example of how Bill Claff's "photographic DR" differs from engineering DR consider Nikon's D7000 versus the D4. On the DXOmark site the D4 has an engineering DR of 13.1 stops and an SNR of...

For purposes of useful dynamic range for photography, it has been suggested that instead of engineering dynamic range based on the absolute noise floor, it is more appropriate to set the minimum...