The first D5 cameras show up in user’s hands right now and also some test pictures are being published.
Especially the high-ISO centric pictures of AndyE at NikonGear are being widely discussed. Derived from test pictures taken by him, also the first analysis of the provided dynamic range are becoming available.
Putting it all together, we are once again seeing an evolution instead of a revolution. If the already published values regarding the dynamic range turn out to be correct, the D5 will be an improvement for some, but a step back for others.
Up to ISO 1600 the D4 has an advantage in dynamic range, up to ISO 400 almost one stop. Above ISO 1600 the D5 gains an advantage. For most of the situations where dynamic range is important, the D4 should have an advantage.
Regarding the noise control with high ISO values, the D5 provides a visible improvement against the D4. The available test pictures provide a far more realistic impression than the early reviews led to believe. Some people claimed to see two to three stops improvement, which is clearly not the case.
Up to ISO 12.800 D4 and D5 are really close. Above that the D5 gains a visible advantage at ISO 25.600 and 51.200. In my opinion the gap is a little less than one stop in favor of the D5. ISO 102.400 is – from my point of view – not usable for any critical type of work, despite the fact that some people rave about the performance at this setting.
Summing it all up, the D5 has less than one stop more usable high ISO, which is in itself a remarkable achievement factoring in the increased resolution. Obviously we have reached a technical level that only allows for incremental improvements.
The last big jumps in high ISO performance took place from D2x to D3 and then again to D3s, but this was more than six years ago. Even the D4 was just an incremental improvement over the D3s. The D4s only offered smaller changes in signal processing and a renaming of HI-1 to ISO 25.600.
For my purposes the D4 maxes out at ISO 12.800. With the D5 the level will most likely move up one step to ISO 25.600.