Constructive Criticism welcome!

[Mike Langdon]

The Histogram on lightroom is spot on the white and black clipping points so must be correct?

[Manfred M]

Mike - let me disagree with both the presentation of the data and the interpretation of it.

By definition, clipping occurs when your black value hits 0 and your white value hits 255. According to the bars on the graph, it shows "dark" clipping at 25 and "light" at around 240. This is not correct.

I see a highlight clip at around +3.8 eV (clipping is where the graph goes horizontal). You never reach that point on the blacks (the lowest value I see is around -5.7), and there is still some room to move as the line never hits 0 eV, i.e the data on the left is never shown as being horizontal, which is where you lose black shadow details. If you go straight line, you'd end up near -7 eV.

Based on the numbers here, I would suggest that at ISO 400, your camera sensor shows a dynamic range of around 10.8 eV, not 6 eV.

If you look at the DxO Mark graphs on the D7000, at ISO 400, it shows a dynamic range of about 11.7, which is fairly close you your measurement.

http://www.dxomark.com/Cameras/Nikon...--Measurements

As a general rule, both dynamic range and colour sensitivity are quoted at the base ISO; as both drop as the gain (ISO) is increased.

[Mike Langdon]

Mike - let me disagree with both the presentation of the data and the interpretation of it.

By definition, clipping occurs when your black value hits 0 and your white value hits 255. According to the bars on the graph, it shows "dark" clipping at 25 and "light" at around 240. This is not correct.

I see a highlight clip at around +3.8 eV (clipping is where the graph goes horizontal). You never reach that point on the blacks (the lowest value I see is around -5.7), and there is still some room to move as the line never hits 0 eV, i.e the data on the left is never shown as being horizontal, which is where you lose black shadow details. If you go straight line, you'd end up near -7 eV.

Based on the numbers here, I would suggest that at ISO 400, your camera sensor shows a dynamic range of around 10.8 eV, not 6 eV.

If you look at the DxO Mark graphs on the D7000, at ISO 400, it shows a dynamic range of about 11.7, which is fairly close you your measurement.

http://www.dxomark.com/Cameras/Nikon...--Measurements

As a general rule, both dynamic range and colour sensitivity are quoted at the base ISO; as both drop as the gain (ISO) is increased.

Thanks for the info. Would you advise retaking the 3 bracketed photos of the colour checker passport (-3, 0, +3) at iso 100 and running it through the software again?
I was surprised at the low dynamic range that it came back with when I first got the meter.

[Manfred M]

Thanks for the info. Would you advise retaking the 3 bracketed photos of the colour checker passport (-3, 0, +3) at iso 100 and running it through the software again?
I was surprised at the low dynamic range that it came back with when I first got the meter.

And this will do what for you?

In my view whatever the output, the information is meaningless in the real world. Your camera has a excellent dynamic range and going to the "best in class" newest model is going to get you perhaps 1/2 stop improvement.

While I am a "techie" and can get wrapped up in specs and other data, at the end of the day, most of this is meaningless and does not impact my image making in any meaningful way. Most of my decisions are based on getting a great looking image, and frankly I can do that with a smartphone, point & shoot, etc. under "normal shooting situations". Granted, DoF, shutter speed, ISO, etc. can be a bit problematic..

[Mike Langdon]

That's how u make a camera profile in the software.
Anyway thank u for all your info and techie stuff I will keep it in mind.
All I can say is we all have our own work flows, as long as I don't clip the shadows or highlights and the histogram represents the light I'm seeing then I must be doing it right.

[Manfred M]

That's how u make a camera profile in the software.
Anyway thank u for all your info and techie stuff I will keep it in mind.
All I can say is we all have our own work flows, as long as I don't clip the shadows or highlights and the histogram represents the light I'm seeing then I must be doing it right.

Understood.

But what does that buy you photographically? Knowing the dynamic range of a camera is neither here nor there for a lot of shooting. I used a lower dynamic range Panasonic GX7 (12.2 eV) versus my Nikon D800 (14.4 eV) on a recent "trip of a lifetime". I didn't have my high end "pro" lenses along and shot in some fairly poor lighting conditions, yet came back with some stunning images.

The only profiling I do with my ColorChecker is to create a colour profile to ensure accurate rendering of the colours for a specific camera under specific lighting conditions. That makes sense to me, but knowing the dynamic range; frankly turning on the "blinkies" on my camera gives me a pretty good idea when I run into issues there (and a rarely do).

I do think it is important to know and understand these camera specs, and know the tradeoffs of pushing the equipment will be.

For the type of shots you are doing, I assume on a tripod, shooting at base ISO is going to give you a pretty incredible dynamic range, regardless of what the camera profile software churns out.

One issue I have with the graphs you have shown is that they are made up of line segments. This is not correct as all of these representations are actually curves. The only time a flat-line response is reasonable is around the mid-tone value (127) and at points where you hit saturation values 0 and 255. When I see a graph like that, I question the accuracy / value of doing the test.

[Mike Langdon]

Based on other posts, I assume you are using the D7000 for these shots?

That camera has a dynamic range of 13.9 eV (stops).

http://www.dxomark.com/Cameras/Nikon/D7000




The Canon 7D Mk III is at 11.7 eV

http://www.dxomark.com/Cameras/Canon/EOS-5D-Mark-III


While I can't comment on the newest FF Canon, as a general rule the Sony sensors used by Nikon over the past 3 years have definitely got better dynamic range than the Canons. I would be highly suspicious of the 6-1/3 stops you are getting from you lightmeter. Something does not add up. If I were to upgrade, I'd likely be moving to the D810, not the 7D Mk III.

What lightmeter are you using? You should be nailing these shots without the use of a spotmeter with that camera.

I have done some testing of my camera, expanding the graph I showed you to the 13.9 stop dynamic range, and taking test shots resulted in the details being recorded in the shadows but having to use a lot of shadow recovery to make the details visible again resulting in a lot of noise in the shadows even at ISO 100. The whites clipped heavily resulting in lose of detail.
I adjusted the meters profile a stop at a time in till the image quality was clean at iso 100, the result was 20 shadows 118 middle grey 245 highlights meaning -3 1/3 stops shadows and +3 for highlights meaning there is only 6 1/3 stops of usable dynamic range before image quality suffers.
That is why it is important to know the usable dynamic range of your camera not just going by the specs that the manufacturer states in the manual.

[Manfred M]

Mike - I think you are mixing up the camera sensor's dynamic range with the dynamic range of your output device. The camera's sensor records a lot more distinct levels than any output device can reproduce.

if you are printing an image, you are dealing with a medium that has perhaps 5 or 6 stops of dynamic range; depending on the paper used and the light you are viewing under. If you are displaying it on a computer screen, you are dealing with a device that has a dynamic range of perhaps 7 to 9 stops (and you'd have to be sitting in a totally black room to be able to the see the differences in the dark areas to resolve to that level), so ultimately, these are going to be the limitations you are working to, not your camera's sensor.

I suspect that this is what you are seeing, rather than the camera's sensor's ability to capture the dynamic range (i.e. if you you are finding this in shadow recovery, your sensor has indeed recorded it). Ultimately, this is the important part of the photographic process; dealing with compressing the dynamic range so it looks good in our output medium.