Our new Dynamic Range measurement system involves shooting a calibrated Stouffer Step Wedge (13 stops total range) which is backlit using a daylight balanced lamp (98 CRI). A single shot of this produces a gray scale wedge from (the cameras) black to clipped white (example below). Each step of the scale is equivalent to 1/3 EV (a third of a stop), we select one step as 'middle gray' and measure outwards to define the dynamic range. Hence there are 'two sides' to our results, the amount of shadow range (below middle gray) and the amount of highlight range (above middle gray).
To most people highlight range is the first thing they think about when talking about dynamic range, that is the amount of highlight detail the camera can capture before it clips to white. Shadow range is more complicated, in our test we stop measuring values below middle gray as soon as the luminance value drops below our defined 'black point' (about 2% luminance) or the signal-to-noise ratio drops below a predefined value (where shadow detail would be swamped by noise), whichever comes first.
Active D-Lighting feature
We've already covered the visible effect of Active D-Lighting on a simple test scene earlier in this review, below you can see a graphical representation of the curve produced by each mode. As you can see none of these modes actually extend highlight range, they do improve shadow range somewhat and also the response from middle gray upwards. The effect is subtle, but useful in some circumstances.
Picture Control presets
The graph below shows the dynamic range response from each of the D3's four Picture Control presets. As you can see each has a slightly different tone curve but none achieves any better highlight range. By a small margin the best overall range (because of its lighter and hence extended shadow range) comes from the Neutral setting. It's worth mentioning that the D3's default tone curve is actually quite contrasty, which produces uncharacteristically (for a pro-level Nikon) 'punchy' out of camera JPEGs, but means the sensor's true capabilities (dynamic range-wise) aren't immediately obvious unless you play around with the picture settings or shoot RAW (see bottom of the page).
The graph below shows how the camera's tone curve and dynamic range is affected by the (admittedly small) range of contrast settings. Whilst the standard/default setting offers the most pleasing 'out of camera' results you can eke a little more (by which we mean maybe a third of a stop) more out of the shadows by opting for the flatter -3 setting.
ISO Sensitivity and Dynamic Range
The D3 has an indicated base sensitivity of ISO 200, sensitivities below this (ISO 160, 125 and 100) are indicated as L0.3, L0.7 and L1.0 respectively. The same is true above ISO 3200 with ISO 6400 indicated as H1.0. As you can see from graph below the compromise at ISO 100 is highlight range which falls nearly a stop (1.0 EV) short of the highlight range seen from ISO 200 upwards.
Using the default settings the D3 delivers somewhere in the region of 8.5 stops of dynamic range from ISO 200 to 1600, and at the optimal ISO 200 setting is basically identical to the D300, though as the results at the bottom of this page show the sensor is capable of a lot more than this would suggest.
|Sensitivity||Shadow range||Highlight range||Usable range|
|ISO 100*||-4.7 EV||2.8 EV||7.5 EV|
|ISO 200||-4.7 EV||3.9 EV||8.6 EV|
|ISO 400||-4.5 EV||3.8 EV||8.3 EV|
|ISO 800||-4.6 EV||3.8 EV||8.4 EV|
|ISO 1600||-4.8 EV||3.7 EV||8.5 EV|
|ISO 3200||-4.3 EV||3.7 EV||8.0 EV|
|ISO 6400||-4.3 EV||3.7 EV||8.0 EV|
|ISO 9000*||-4.0 EV||3.7 EV||7.7 EV|
|ISO 12,800*||-3.4 EV||3.7 EV||7.1 EV|
|ISO 25,600*||-3.0 EV||3.6 EV||6.6 EV|
* Non-standard sensitivities
Dynamic Range compared
There's a not a lot of difference between any of the cameras near the top of the market; all offer somewhere in the 8.5 stops region, with Canon's slightly harsher tone curve clipping highlights a little earlier.
|Nikon D3 (ISO 200)||-4.7 EV||3.9 EV||8.6 EV|
|Nikon D300 (ISO 200)||-4.7 EV||4.1 EV||8.8 EV|
|Canon EOS 5D (ISO 100)||-4.7 EV||3.5 EV||8.2 EV|
|Canon EOS 1DS Mk3 (ISO 100)||-5.1 EV||3.5 EV||8.6 EV|
The wedges below are created by our measurement system from the values read from the step wedge, the red lines indicate approximate shadow and highlight range (the dotted line indicating middle gray).
Experience has told us that there is typically around 1 EV (one stop) of extra information available at the highlight end in RAW files and that a negative digital exposure compensation when converting such files can recover detail lost to over-exposure. As with previous reviews we settled on Adobe Camera RAW for conversion to retrieve the maximum dynamic range from our test shots.
As usual the default Adobe Camera RAW conversion delivers less dynamic range than JPEG from the camera (a more contrasty tone curve and very little noise reduction in shadows). Simply switching to 'Auto' in the ACR conversion dialog reaps huge rewards (we measured the result to have exactly 12 stops of dynamic range), and in our tests with real world shots produced superb results with images that seemed to be over exposed beyond redemption.
It's also worth noting that we are only plotting the 14-bit RAW mode on the graph below, but (like the D300) this is simply because the result for this test is identical. Where 14 bit will give you an advantage is when you're 'pushing' or 'pulling' using digital exposure compensation (as shown at the bottom of the page), where you're less likely to hit posterization problems when working with severely over- or under- exposed shots. In practice the difference is minimal (especially with extreme under exposure, where noise will be the great leveler), though there seems little reason not to shoot 14-bit to be on the safe side.
- ACR Default: Exp. 0.0 EV, Blacks 5, Contrast +25, Curve Medium
- ACR Auto: Exp. -0.2 EV, Recovery 32, Brightness 0, Contrast 0, Curve Linear
The D3's rather contrasty default tone curve, combined with the hardware advantage offered by those huge pixels, means that there's rather more than a stop of headroom in ISO 200 shots, giving the D3 an usually wide exposure latitude, able to pull back both shadow and highlight detail if your exposure goes awry in the press scrum or when trying to follow the action at 9 frames per second. As the example below shows the ability to pull back color information is impressive, and though you can't expect miracles these are some of the most pliable RAW files we've yet seen. It's not quite Fujifilm S5 Pro level, but with careful processing it's not far off.
|Adobe Camera RAW default conversion||Adobe Camera RAW with -2.0 EV digital comp.|
This example, not the proudest moment in my photographic career, was an accidental shot taken whilst fiddling about with the D3 when I first started using it. But it's also a perfect example of just how much you can get back from over-exposed shots if you're in a tight spot. For many cameras (including professional models) a shot like this would be a write-off, but the D3's sensor and 14-bit RAW files are capable of pulling something usable out of what appears to be a heavily clipped exposure.
There is some channel clipping here (the bottom right hand leaf in the 100% crop is a good example), but again it's surprising how much color information you can rescue. At the other end of the scale (lifting shadows to deal with under exposure) you'll also get pretty successful results at lower ISO settings, though underexposing very high ISO shots will introduce lots of visible noise (and the possibility of banding) if you try to use this level of positive digital exposure compensation.
|Adobe Camera RAW default conversion||Adobe Camera RAW with -2.45 EV digital comp.|