paulraphael
Member
I ran a little test to see exactly how the d800's dynamic range compares with meter readings, camera histograms, and Lightroom's clip indicators.
This was not a conventional test by any means, and I looked only at the highlight end of the spectrum. I plan to look at shadows in a systematic way soon, but this is trickier ... subjective results depend on your tolerance for noise, which is going to be dependent on factors that vary from image to image. On the highlight end, either there's detail or there isn't.
I used an image on my computer screen for a test target. The image is flat gray, with a series of bars along one side that are just a couple of percent lighter than the background.
Being an old black and white large format guy, I'm using zone system vocabulary, so forgive me if I sound like I'm from the wrong century.
Calling the camera meter's suggested exposure Zone V (assuming it's aiming for 18% gray), I used this as the base exposure. I then made a series of exposures, each one exposed a stop more than the previous.
Around Zone Zone 9 (4 stops above base exposure) the histograms indicated clipping. I realize this is just a product of my chosen in-camera jpeg profile (in my case Camera Standard with added sharpening).
At zone 12 (7 stops above base exposure) lightroom indicated clipping, even with highlights and whites dialed down.
However, I don't know what this means, because there was no detail discernible in any image above Zone 10 (5 stops above base). Beyond this point, the lighter bars vanish into the background. Lightroom doesn't indicate clipping, and will darken the image below the full white of the screen, but there is no variation between light and dark visible in the image... so at this point we can consider the image to be clipped.
In summary, at standard settings the camera histogram shows clipping about a stop before actual clipping, but Lightroom (which really should know better) has its own ideas, which have nothing to do with the saturation of the photosite. You will be out of captured detail or tonal variation well before Lightroom warns you.
The good news is that 5 stops beyond middle gray is excellent for a sensor, and the jpeg histograms give a pretty fair warning, with about a stop of wiggle room.
This was not a conventional test by any means, and I looked only at the highlight end of the spectrum. I plan to look at shadows in a systematic way soon, but this is trickier ... subjective results depend on your tolerance for noise, which is going to be dependent on factors that vary from image to image. On the highlight end, either there's detail or there isn't.
I used an image on my computer screen for a test target. The image is flat gray, with a series of bars along one side that are just a couple of percent lighter than the background.
Being an old black and white large format guy, I'm using zone system vocabulary, so forgive me if I sound like I'm from the wrong century.
Calling the camera meter's suggested exposure Zone V (assuming it's aiming for 18% gray), I used this as the base exposure. I then made a series of exposures, each one exposed a stop more than the previous.
Around Zone Zone 9 (4 stops above base exposure) the histograms indicated clipping. I realize this is just a product of my chosen in-camera jpeg profile (in my case Camera Standard with added sharpening).
At zone 12 (7 stops above base exposure) lightroom indicated clipping, even with highlights and whites dialed down.
However, I don't know what this means, because there was no detail discernible in any image above Zone 10 (5 stops above base). Beyond this point, the lighter bars vanish into the background. Lightroom doesn't indicate clipping, and will darken the image below the full white of the screen, but there is no variation between light and dark visible in the image... so at this point we can consider the image to be clipped.
In summary, at standard settings the camera histogram shows clipping about a stop before actual clipping, but Lightroom (which really should know better) has its own ideas, which have nothing to do with the saturation of the photosite. You will be out of captured detail or tonal variation well before Lightroom warns you.
The good news is that 5 stops beyond middle gray is excellent for a sensor, and the jpeg histograms give a pretty fair warning, with about a stop of wiggle room.