Doug Kerr
Well-known member
Hi, Alex,
Be glad to. Send me an e-mail so I will have your e-mail address:
doug.kerr@att.net
Indeed!
Here is what the black point and white point settings do with regard to the pixels that are included in the statistics:
With Outside Range unchecked (to see this box you need to be in the Exposure display mode), then:
The sensels that are included in the statistics in the "black point" panel are those for which:
BP>=DN>2048 (more about 2048 in a minute)
where BP is the black point setting and DN is the data number (in ADU) of the sensel.
The sensels that are included in the statistics in the "white point" panel are those for which:
2017>DN>WP
where WP is the white point setting.
With Outside Range checked, then:
The sensels that are included in the statistics in the "black point" panel are those for which:
BP>=DN
The sensels that are included in the statistics in the "white point" panel are those for which:
DN>=WP
The significance of the 2048 is that values below that are considered to be in the "lower group" and values at or above that are considered to be in the "upper group". The mystic significance of this, or the premise for that number, has not yet some to me.
Now, as to the effect of those settings beyond the screening of value for the gathering of statistics, I am still sorting that out.
Best regards,
Doug
I don't have it, so I'd be grateful if you could send it to me.
Be glad to. Send me an e-mail so I will have your e-mail address:
doug.kerr@att.net
Sure.Very interesting. I suspected something like that. However, there still seems to be something off, as I did not get values within a certain range, but every single time only two distinct values.
I'm still figuring all that out.Hm, even more interesting. My values have never reached the max (and because of Canon's offset also not 0). Are you sure that this is the range of the actual RAW data and not the result of some scaling Rawnalyze performs with the white and black point setting (if it indeed does that; see below)?
I have never fully understood what the black and white point settings do in Rawnalyze (but then again, I didn't have a help file). Do those settings simply operate as thresholds of sorts and discard everything below and above them and then scale the data? Uncertainties like that made me move on to Iris...
Indeed!
Here is what the black point and white point settings do with regard to the pixels that are included in the statistics:
With Outside Range unchecked (to see this box you need to be in the Exposure display mode), then:
The sensels that are included in the statistics in the "black point" panel are those for which:
BP>=DN>2048 (more about 2048 in a minute)
where BP is the black point setting and DN is the data number (in ADU) of the sensel.
The sensels that are included in the statistics in the "white point" panel are those for which:
2017>DN>WP
where WP is the white point setting.
With Outside Range checked, then:
The sensels that are included in the statistics in the "black point" panel are those for which:
BP>=DN
The sensels that are included in the statistics in the "white point" panel are those for which:
DN>=WP
The significance of the 2048 is that values below that are considered to be in the "lower group" and values at or above that are considered to be in the "upper group". The mystic significance of this, or the premise for that number, has not yet some to me.
Now, as to the effect of those settings beyond the screening of value for the gathering of statistics, I am still sorting that out.
I'm not sure exactly what you mean by "the low values".Couldn't the low values simply be noise at very dark tones that fluctuates around the offset?
Best regards,
Doug