R8 14-bit in 20fps ?

koenkooi wrote:

cocoanud wrote:

Hi,

Was going through this preview by Jared Polin of the R8 - https://youtu.be/T7NJlqLGwvM?t=358

At around 5:58, he says that R8 does 14-bit in Electronic Shutter mode at 20fps ?

A lot of reviewers that were invited to that location have said the same in their reviews. So I believe someone from Canon did say that, but I think that Canon person was mistaken.

Canon's own publications have made this mistake in the past; they said that the R7 is 14-bit in ES mode, which is total nonsense.  The people presenting data to the public are not the people who actually understand what is going on under the hood; people who don't know the difference between a 14-bit raw image and 14-bit readout of the sensor.  14-bit readout takes about 4x as long as 12-bit readout, so it is not trivial to give 14 bits at a high framerate without something like stacked-sensor technology.

Sounds a bit daft but could be true as well… does anyone have more info on this ? I tried looking into the manual but haven’t been able to find this info.

Unlike other Canon manuals, the R8 manual doesn't say anything about lower bit depths in e-shutter! This further confirms for me that ES is 12-bit all the way, if it wasn't the manual would've proudly pointed it out.

I hope the manual gets updated with the usual shutter mode table that lists the applicable bit depths. But I'm not getting my hopes up for 14-bit e-shutter!

As soon as Photons2Photos has the R8's PDR, you can see if its the same in ES and mechanical shutter.  In the meantime, anyone with an ISO 100 raw for both ES and MS on the R8 can look at the noise in the black border at the left of the image and see if they are the same.  You should expect about 2x - 3.5x the noise in these borders with 12-bit readout.

Zorgsonic76 wrote:

But should it not be possible to give us a 14-bit-readout with slower frame rates oder at least in single shot? Like the Sony A7IV does? This would be incredibly helpful!

I could be wrong, but I am assuming that the analog2digital converter is a ramp comparator, which would mean that it takes 4x as long to read out each pixel or pixel row with 14-bit readout which would result in a rolling shutter 4x as slow as 12-bit.

That would greatly reduce the usefulness of e-shutter mode with all R bodies but the R3.

For the R7's sensor that would be about 1/8s rolling shutter.  About 1/15 for the R5.

koenkooi wrote:

Zorgsonic76 wrote:

But should it not be possible to give us a 14-bit-readout with slower frame rates oder at least in single shot? Like the Sony A7IV does? This would be incredibly helpful!

It is possible, with the caveat that the rolling shutter effect wil get 4 times worse. Good for landscape and still
life, not so much for things that move.

Camera motion becomes problematic, too, with narrow angles of view.  Shooting a rock with an 800mm lens would be difficult, hand-held, even at 1/8000.

MAC wrote:

John Sheehy wrote:

As soon as Photons2Photos has the R8's PDR, you can see if its the same in ES and mechanical shutter. In the meantime,

anyone with an ISO 100 raw for both ES and MS on the R8 can look at the noise in the black border at the left of the image

black border at left of image? please explain

and see if they are the same. You should expect about 2x - 3.5x the noise in these borders with 12-bit readout.

Every Canon raw image has pixels on the top and left that are covered and never exposed to light, which is how black levels are determined.  The strip at the top is often altered and is a bit small, but the strip on the left has enough pixels to do some measurements.  IOW, every Canon raw (except maybe mRAW and sRAW) has this built-in "mini black frame" that is normally left out of conversions, but RawDigger can show it and let you measure it.  You must set the blackpoint to zero, though, otherwise the masked area gets clipped and then it can't be measured properly.