Z6 vs Z6 III High ISO and ISO DR comparison, Dual Gain ISO

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Horshack

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Base ISO Dynamic Range Comparison

Here is a full ISO 100 DR comparison between the Z6 and Z6 III. This allows you to compare the DR differences of these cameras for whatever the maximum exposure boosting you normally do for your photography.

Notes:
  • Shot under studio-quality 5600K LED lighting
  • Lens is Nikon Z 50mm f/1.8 S @ f/8
  • Starting shutter speed ISO 100 is 1/6, which is doubled for each exposure, which creates a progressively-increasing underexposure. The raws are processed to match the brightness of the properly-exposed 1/6 exposure using ACR exposure controls.
  • Lossless 14-bit raws with electronic shutter
  • Processed in ACR/LR with camera neutral profile, all settings cleared except for matched WB and 45/0.7/35 sharpening. NR disabled
  • These are 100% crops.
  • Look to the black lens bag in the upper-right to see the deepest shadows, where the differences between the cameras are most noticeable.
Each of these Z6 vs Z6 III animation links is around 35MB. They are each 2250 x 1500 in size, so you may need to click once in your browser after loading so that they're shown at 100% instead of zoomed-to-fit in your browser. Noise performance differences between the two cameras only start to become noticeable at ISO 3200.

Animation: Z6 vs Z6 III, ISO 100, Properly Exposed
Animation: Z6 vs Z6 III, ISO 100, Minus 1EV
Animation: Z6 vs Z6 III, ISO 100, Minus 2EV
Animation: Z6 vs Z6 III, ISO 100, Minus 3EV
Animation: Z6 vs Z6 III, ISO 100, Minus 4EV
Animation: Z6 vs Z6 III, ISO 100, Minus 5EV
Animation: Z6 vs Z6 III, ISO 100, Minus 6EV
Animation: Z6 vs Z6 III, ISO 100, Minus 7EV
Animation: Z6 vs Z6 III, ISO 100, Minus 8EV
Animation: Z6 vs Z6 III, ISO 100, Minus 9EV
Animation: Z6 vs Z6 III, ISO 100, Minus 10EV

Conclusion: The Z6 III has noticeably less base ISO DR vs the Z6, although this unlikely to affect all but the most extreme pushes of exposures in post.

High ISO Comparison

Here is a full ISO noise comparison between the Z6 and Z6 III, shot with the same methodology as the base ISO DR but with the ISO increasing in tandem with the shutter speed increases, which is how ISO is typically used.

Animation: Z6 vs Z6 III, ISO 100
Animation: Z6 vs Z6 III, ISO 200
Animation: Z6 vs Z6 III, ISO 400
Animation: Z6 vs Z6 III, ISO 800
Animation: Z6 vs Z6 III, ISO 1600
Animation: Z6 vs Z6 III, ISO 3200
Animation: Z6 vs Z6 III, ISO 6400
Animation: Z6 vs Z6 III, ISO 12800
Animation: Z6 vs Z6 III, ISO 25600
Animation: Z6 vs Z6 III, ISO 51200

Conclusion: The Z6 III has marginally worse High ISO performance but only at the extreme ends of the ISO range, where other noise would usually limit the usability of the photo.

Dual Gain is at ISO 800

The Z6 III new sensor has a dual-gain ISO that begins at 800. This means its deep shadow noise is significantly lower at ISOs >= 800. The practical application of this is to not hesitate moving to ISO 800 in low light and when shooting conditions permit.

Methodology for discovering the Dual Gain ISO
I set up a scene that's -7EV underexposed at ISO 100. With the shutter speed and aperture fixed, I then vary only the ISO in 1/3 increments up to ISO 12,800. This means each successive image gets 0.33EV brighter, so that at ISO 12,800 the image is now "properly exposed" in terms of the expected brightness. I then bring all the raws into ACR/PS and increase the brightness of each image so that they all have the same output brightness. For the ISO 100 raw I boost by +7EV in ACR/PS, ISO 125 by +6.66EV, ISO 160 by 6.33EV, etc..., up until ISO 12,800 where there is no ACR/PS brightness adjustment.

By using a fixed exposure I'm isolating any noise difference to ISO gain alone. Most people who do a noise ramp vary the exposure and ISO together, so that they reduce the exposure (ie, faster shutter speed or small aperture) as the ISO increases. That matches how people actually shoot in low-light conditions but by varying the exposure they're incorporating not just ISO gain noise differences but differences in shot noise. It's a lot easier to visually see the dual ISO gain point with the ISO gain noise isolated instead.

Animation: Dual Gain ISO check: ISO 100 to 12,800, 100% Crop, NR Disabled (49 MB)
 
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