Some random Z6 III tech musings

[beatboxa]

• The 4K/120p has a DX cro. Based on the Gerald Undone's 9.47ms rolling shutter measurement for 6K/24p, Nikon could have achieved 4K/120p with just a 1.15x crop (9.47 * .85 = 8.05ms = 1/124), comparable to the A7S III's 4k/120p 1.1x crop. I'm guessing Nikon didn't want to go through the trouble of adding additional crop factor support in the firmware.
• Richard Butler measured a 14-bit full-sensor sills-mode readout time of 14.6ms (1/68.5). It would be nice if Nikon didn't drop 12-bit raw stills support in Expeed 7, as that would allow the Z6 III's electronic shutter to run at 1/105, which I base on the 9.47ms rolling shutter for 6K video, which is 12-bit. Keeping 12-bit raw support would've further reduced rolling shutter artifacts and also increase the electronic shutter flash x-sync from 1/60.
• Steve Perry does a great job demonstrating the Z6 III's blackout for the various frame rates in his YouTube video (link jumps to 8:55)
• I was hoping Nikon would move away from their video-based pre-capture implementation on the Z8/Z9 to a stills-based implementation for the Z6 III, so that it would get raw support but that probably wont come until the next spin of Expeed and will probably require Nikon to be more generous with the DRAM buffer size. The 6K60p full-sensor readout speed at least offers full-sized jpgs for the Z6 III's C60 pre-capture.
• 3D LUT support would've been great instead of the "Flexible Color" feature Nikon added, although perhaps "Flexible Color" will turn out to be more useful than expected depending on how much flexibility Nikon put into the mechanism.
• The 6K fully-sampled internal NRAW is new to the Z line and quite useful for those don't want to shoot 8K NRAW to get full-sensor NRAW sampling like on the Z8/Z9.

Regarding the 12-bit vs 14-bit, there’s a lot we don’t know, including whether or not the sensor switches to 12-bit mode or 14-bit mode automatically when certain conditions are met (eg if ISO is 400 or higher), in order to optimize things. Not saying this happens: just pointing out that we don’t know whether it does or doesn’t. And it would make a lot of sense for Nikon to do this.

Remember that a 14-bit sensor read and a (lossless) compressed 14-bit raw file are two different things—and a 14-bit lossless file can always contain a 12-bit sensor read with no loss in quality and with no increase in file size. And in many common scenarios—particularly those requiring speed—12-bit will offer no image quality loss relative to 14-bit (example: low light /high ISO shooting). We also know that Nikon’s now using intoPix TicoRaw on the Expeed 7; and that the Zf, which uses the same sensor as the Z6 and Z6ii doesn’t allow for a user-selectable 12-bit sensor readout (except video).

As you indicated, Nikon seems to have moved away from supporting 12-bit sensor readout for stills, even on slower readout sensors that would benefit from the faster readout with no loss of quality starting at intermediate ISOs. That's why I doubt the Z6 III has 12-bit raw support.

Just to clarify, what I was writing is that Nikon seems to have moved away from 12-bit raw files, not necessarily moving away from 12-bit sensor readouts for stills. I still want to see if they’ve moved away from 12-bit sensor readouts (that are contained within a 14-bit raw file).

I’d be interested to see if the sensor read speeds are the same in all circumstances. I’d also be interested in if you could clarify the shooting conditions on your excellent sensor speed site instead of just “stills”.

If you click on a given model in the live results table you'll arrive at a detailed table showing all the permutations of stills configurations that were measured, including single-shot, continuous (at various speeds), ISOs, JPEG, etc...

Thanks! I’ll take a look. I’m guessing the data will largely answer my question. And if not, I might run some tests on my Z8 or eventual Z6iii. It doesn’t necessarily seem like an easy thing to test (since they’re lossless compressed); and stills readout might be the best way to check.

 

[Horshack]

• The 4K/120p has a DX cro. Based on the Gerald Undone's 9.47ms rolling shutter measurement for 6K/24p, Nikon could have achieved 4K/120p with just a 1.15x crop (9.47 * .85 = 8.05ms = 1/124), comparable to the A7S III's 4k/120p 1.1x crop. I'm guessing Nikon didn't want to go through the trouble of adding additional crop factor support in the firmware.
• Richard Butler measured a 14-bit full-sensor sills-mode readout time of 14.6ms (1/68.5). It would be nice if Nikon didn't drop 12-bit raw stills support in Expeed 7, as that would allow the Z6 III's electronic shutter to run at 1/105, which I base on the 9.47ms rolling shutter for 6K video, which is 12-bit. Keeping 12-bit raw support would've further reduced rolling shutter artifacts and also increase the electronic shutter flash x-sync from 1/60.
• Steve Perry does a great job demonstrating the Z6 III's blackout for the various frame rates in his YouTube video (link jumps to 8:55)
• I was hoping Nikon would move away from their video-based pre-capture implementation on the Z8/Z9 to a stills-based implementation for the Z6 III, so that it would get raw support but that probably wont come until the next spin of Expeed and will probably require Nikon to be more generous with the DRAM buffer size. The 6K60p full-sensor readout speed at least offers full-sized jpgs for the Z6 III's C60 pre-capture.
• 3D LUT support would've been great instead of the "Flexible Color" feature Nikon added, although perhaps "Flexible Color" will turn out to be more useful than expected depending on how much flexibility Nikon put into the mechanism.
• The 6K fully-sampled internal NRAW is new to the Z line and quite useful for those don't want to shoot 8K NRAW to get full-sensor NRAW sampling like on the Z8/Z9.

Regarding the 12-bit vs 14-bit, there’s a lot we don’t know, including whether or not the sensor switches to 12-bit mode or 14-bit mode automatically when certain conditions are met (eg if ISO is 400 or higher), in order to optimize things. Not saying this happens: just pointing out that we don’t know whether it does or doesn’t. And it would make a lot of sense for Nikon to do this.

Remember that a 14-bit sensor read and a (lossless) compressed 14-bit raw file are two different things—and a 14-bit lossless file can always contain a 12-bit sensor read with no loss in quality and with no increase in file size. And in many common scenarios—particularly those requiring speed—12-bit will offer no image quality loss relative to 14-bit (example: low light /high ISO shooting). We also know that Nikon’s now using intoPix TicoRaw on the Expeed 7; and that the Zf, which uses the same sensor as the Z6 and Z6ii doesn’t allow for a user-selectable 12-bit sensor readout (except video).

As you indicated, Nikon seems to have moved away from supporting 12-bit sensor readout for stills, even on slower readout sensors that would benefit from the faster readout with no loss of quality starting at intermediate ISOs. That's why I doubt the Z6 III has 12-bit raw support.

Just to clarify, what I was writing is that Nikon seems to have moved away from 12-bit raw files, not necessarily moving away from 12-bit sensor readouts for stills. I still want to see if they’ve moved away from 12-bit sensor readouts (that are contained within a 14-bit raw file).

Understood, my reply is that Nikon has moved away from not just 12-bit raws but 12-bit raw readouts as per my readout speed measurements on the Z9/Z8/Zf.

 

[HRS]

(replying to myself)

One problem The Fro's video did not show was a tendency he found in the Zf and Z8 to sometimes show an eye in-focus in the the viewfinder, but not in the resulting image. For example, here: https://youtu.be/Kqlbs3ikewU?t=670s at around 11:30.

This is even more encouraging!

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One of the signs you're in Cognitive Dissonance: A refusal to toss aside your closely held beliefs when confronted by evidence that you were wrong all along.