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Author Topic: 16 Bit Color for Hasselblad X1D but only 14 bit for Fuji GFX?  (Read 4628 times)

wallpaperviking

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16 Bit Color for Hasselblad X1D but only 14 bit for Fuji GFX?
« on: January 15, 2017, 02:59:09 AM »


Why does the Hasselblad X1D appear listed as having 16-Bit color in various spec sheets whereas the Fuji GFX is still only "rumoured" to have 16 Bit (quite possibly 14 bit) color? 

I would have thought sharing the exact same sensor would have put them in the same league together?
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BartvanderWolf

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Re: 16 Bit Color for Hasselblad X1D but only 14 bit for Fuji GFX?
« Reply #1 on: January 15, 2017, 05:14:19 AM »

I would have thought sharing the exact same sensor would have put them in the same league together?

Hi,

There is more to a camera than the sensor alone. Supporting electronics (such as the Analog to Digital Converter (ADC)) and the file format and Raw conversion need to be adapted too.

If done well, then a true 16-bit pipeline will give superior results (like the Phase One IQ3 100 does).

If and how well that's implemented in the Hasselblad and Fuji offerings remains to be seen. When Raw files from production cameras become available then an objective analysis will become possible. RawDigger is usually pretty fast with delving into the specifics of the file peculiarities, also because the Raw conversion libraries are used for Fast Raw Viewer, which should be useful with such large file sizes.

Cheers,
Bart
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voidshatter

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Re: 16 Bit Color for Hasselblad X1D but only 14 bit for Fuji GFX?
« Reply #2 on: January 15, 2017, 05:15:22 AM »

Perhaps Fuji just don't bother with it. 16-bit is more of a marketing scheme. Technically these Sony CMOS sensors, while being the state-of-the-art in terms of dynamic range, only has no more than 14 stops of dynamic range at pixel level, and there is no practical advantage to have more than 14-bit encoding in their raw files. The CCD sensors of course cannot benefit from 16-bit raw files given that they even have less dynamic range than these Sony CMOS sensors.
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ErikKaffehr

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Re: 16 Bit Color for Hasselblad X1D but only 14 bit for Fuji GFX?
« Reply #3 on: January 15, 2017, 09:08:15 AM »

Hi,

The X1D is a 14 bit device. Hasselblad actually states this quite clearly. 16-bit colour is marketing nonsense.

The 100 MP sensor used in the Phase One IQ3-100 is in fact a 16 bit device delivering 15 bits worth of data.

I enclose a raw digger histogram, it has peaks for each fourth channel. The in between channels having data indicates that some processing was done on the data before writing the raw file.

Best regards
Erik


Why does the Hasselblad X1D appear listed as having 16-Bit color in various spec sheets whereas the Fuji GFX is still only "rumoured" to have 16 Bit (quite possibly 14 bit) color? 

I would have thought sharing the exact same sensor would have put them in the same league together?

BartvanderWolf

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Re: 16 Bit Color for Hasselblad X1D but only 14 bit for Fuji GFX?
« Reply #4 on: January 15, 2017, 11:20:13 AM »

Hi,

The X1D is a 14 bit device. Hasselblad actually states this quite clearly. 16-bit colour is marketing nonsense.

Hi Erik,

I'm a bit more cautious, given my earlier experience with the early samples of the Phase One IQ3 100. The early samples were shot in 14-bit mode, but later examples became available in 16-bit mode. I do not know if the Hasselblad will offer such a setting (and the firmware seems to be a works in progress).

Quote
The 100 MP sensor used in the Phase One IQ3-100 is in fact a 16 bit device delivering 15 bits worth of data.

As we found out later, there is a special setting that delivers a different raw format to accommodate that 16-bit data pipeline. My measurements indicated an increase from 13.65 stops at nominal ISO 50 in 14-bit mode to a DR of 14.39 stops in 16-bit mode. Not quite the claimed 15-bits but 14.36 stops of engineering DR is still very high (given that one usually loses at least 0.5 stop to residual noise sources), and a significant enough improvement albeit at the cost of (even) larger filesizes.

Quote
I enclose a raw digger histogram, it has peaks for each fourth channel. The in between channels having data indicates that some processing was done on the data before writing the raw file.

Yes, although I'll reserve my final analysis for regular production models with up-to-date firmware.

These are interesting times ...

It will also be interesting to see how the available lens ranges evolve, and how well available lenses with adapters will match a Digital sensor at the given flange distances and given filter stacks (if any). Lenses designed for digital sensors are different from analog/film designs, and dedicated lenses for mirrorless cameras are most likely different as well.

Cheers,
Bart
« Last Edit: January 15, 2017, 11:25:18 AM by BartvanderWolf »
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ErikKaffehr

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Re: 16 Bit Color for Hasselblad X1D but only 14 bit for Fuji GFX?
« Reply #5 on: January 15, 2017, 11:58:06 AM »

Hi Bart,

I have been involved in the IQ3100 SNAFU…

But, all implementations of the 44x33 mm sensor have been 14 bits. Hasselblad claims up to 14 EV DR, which is a clear indication that there is not more than 14 bits worth of data.

Once you get beyond 14 EV of DR, you would need 15 bits of data to represent that dynamic range.

Many photographers quote "16 bit colour" as an advantage of MFD, but Photoshop even cannot handle 16 bit of colour unless it is used in 32-bits or floating point mode.

As I can see it, 16 bit colour is just marketing speak. Phase one even used to employ a 14 bit file format. That was the cause of the IQ3 100MP SNAFU. Old versions of RawDigger interpreted the data in the old 14-bit format.

Anders Torger has discovered that the IQ3 100 MP files actually were using 16 bits instead of the original 14 bits.

Now, using 14 bit data paths on the older backs, including the IQ 350, was sound engineering judgement, but calling those data 16 bit files was simply a lie. A marketing lie, but still a lie.

The IQ3 100 MP delivers beyond 14 bits, so Phase One modified their pipeline to 16 bits, good.

I am surprised to see that the IQ3 100 MP delivers past 14 bits, but it seems to be the case and I have no objection with it.

Best regards
Erik

Hi Erik,

I'm a bit more cautious, given my earlier experience with the early samples of the Phase One IQ3 100. The early samples were shot in 14-bit mode, but later examples became available in 16-bit mode. I do not know if the Hasselblad will offer such a setting (and the firmware seems to be a works in progress).

As we found out later, there is a special setting that delivers a different raw format to accommodate that 16-bit data pipeline. My measurements indicated an increase from 13.65 stops at nominal ISO 50 in 14-bit mode to a DR of 14.39 stops in 16-bit mode. Not quite the claimed 15-bits but 14.36 stops of engineering DR is still very high (given that one usually loses at least 0.5 stop to residual noise sources), and a significant enough improvement albeit at the cost of (even) larger filesizes.

Yes, although I'll reserve my final analysis for regular production models with up-to-date firmware.

These are interesting times ...

It will also be interesting to see how the available lens ranges evolve, and how well available lenses with adapters will match a Digital sensor at the given flange distances and given filter stacks (if any). Lenses designed for digital sensors are different from analog/film designs, and dedicated lenses for mirrorless cameras are most likely different as well.

Cheers,
Bart

douglevy

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Re: 16 Bit Color for Hasselblad X1D but only 14 bit for Fuji GFX?
« Reply #6 on: January 15, 2017, 06:31:38 PM »

Erik can you clarify/explain the 32-bit or floating point mode point? Thanks!

BobShaw

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Re: 16 Bit Color for Hasselblad X1D but only 14 bit for Fuji GFX?
« Reply #7 on: January 15, 2017, 08:11:48 PM »

The X1D is a 14 bit device. Hasselblad actually states this quite clearly. 16-bit colour is marketing nonsense.
Where does Hasselblad say this?
I read on the website:
Colour definition 16 bit; Dynamic range up to 14 stops

How does colour depth or bits per pixels relate to dynamic range anyway?

All I know is that my 2007 H3DII has 16 bits of this "marketing nonsense" and the colour is far better than my new 14 bit Canon.
Perhaps Fuji has 14 bits because it is a lesser camera, and there is nothing wrong with that for the market they choose.
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alan_b

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Re: 16 Bit Color for Hasselblad X1D but only 14 bit for Fuji GFX?
« Reply #8 on: January 15, 2017, 11:08:56 PM »

Erik can you clarify/explain the 32-bit or floating point mode point? Thanks!

Also known as a High Dynamic Range image, can contain many more stops of dynamic range.

douglevy

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Re: 16 Bit Color for Hasselblad X1D but only 14 bit for Fuji GFX?
« Reply #9 on: January 16, 2017, 12:11:39 AM »

No, I get that. It's the "Photoshop even cannot handle 16-bit color," part that confused me.

ErikKaffehr

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Re: 16 Bit Color for Hasselblad X1D but only 14 bit for Fuji GFX?
« Reply #11 on: January 16, 2017, 02:17:35 AM »

Hi,

This shows that desinformation works.

Dynamic range is range between highest reproducible white and lowest reproducible dark. Darks are always limited by noise.

Light, on it's own, is noisy. It is coming in quanta. A pixel can capture so and so many photons (quanta of light) your  sensor on the Hassy can hold around 60000 electron charges per pixel. Normally, an electron charge corresponds to a captured photon.

As I said, the light itself is noisy. If you would photograph a white piece of paper overexposing 3 EV for the white you would have around ETTR (Expose To The Right) exposure with the sensor fully utilised. In this the paper white would be represented by a bell curve, centered around 60000 with 65 of the pixels having between 59750 and 60250 electron charges.

Now, looking at the other end the Hasselblad sensor has a readout noise of around 10.5 e-, if I recall correctly. So the ratio between the Full Well and the readout noise would be 60000 / 10.5 -> 6190. If we will represent that range with a binary number it would need log(6190) / log (2) -> 12.5 bits. So that sensor is a barely 13 bit device.

To explain the difference between your Canon and Hasselblad you need to go somewhere else. One factor is that your Canon has fewer pixels and Canon has quite noisy readout, too. If you look at actual pixels you would see the noise at the pixel level. But at any other size the Hasselblad would use more pixels for each visible dot. That would reduce the noise. But not because it has more bits of data but because it has more pixels.

The major factors for colour rendition are in all probability two. One is the Color Filter Array. The pixels don't have colour, they just count photons. Colour is added by using a Color Filter Array.

The Kodak CCDs used to have quiet extreme CFA designs, probably optimised for studio light. Canon's are often used in mixed light and under poor light conditions. Their CFA designs are more general purpose and probably more permissive.

The other factor is the colour profile. The signal coming out of the sensor is a voltage, that is amplified and converted to binary data by an ADC, which happens to be a commercial flash converter older cameras.

The binary data is converted to RGB data using a colour profile. Hasselblad is known for well made colour profiles.

Later generation CMOS sensors have moved the ADCs to the sensor. There is normally thousands of them, one for each column. This allows to use slow but precise converters. But it also means that the vendor of the sensor decides the number of bits and the Sony sensor used by Fuji and Hasselblad is a 14-bit device.

The enclosed screen dump of the RawDigger histogram of a raw file from the X1D-50c clearly indicates that each fourth channel contains data. That the gaps also contain data indicates that some image manipulation has been done on the raw data. That could be flat field correction of the raw data, or simply some dither noise added.

The second screen dump is coming from an Phase One IQ350 shot, courtesy of Digital Transitions. This shows no sign of postprocessing in raw. Phase One also claims 16 bit colour. The IQ 350 uses the same Sony sensor as the X1D-50c

The last attachments shows the white patch on IQ 350 shot. It shows what a great spread of signal a single patch can have. Some of that may come from the rough surface of the patch, but most is coming from variation of incident photons.

Best regards
Erik



Where does Hasselblad say this?
I read on the website:
Colour definition 16 bit; Dynamic range up to 14 stops

How does colour depth or bits per pixels relate to dynamic range anyway?

All I know is that my 2007 H3DII has 16 bits of this "marketing nonsense" and the colour is far better than my new 14 bit Canon.
Perhaps Fuji has 14 bits because it is a lesser camera, and there is nothing wrong with that for the market they choose.

voidshatter

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Re: 16 Bit Color for Hasselblad X1D but only 14 bit for Fuji GFX?
« Reply #12 on: January 16, 2017, 10:58:07 PM »

Where does Hasselblad say this?
I read on the website:
Colour definition 16 bit; Dynamic range up to 14 stops

How does colour depth or bits per pixels relate to dynamic range anyway?

All I know is that my 2007 H3DII has 16 bits of this "marketing nonsense" and the colour is far better than my new 14 bit Canon.
Perhaps Fuji has 14 bits because it is a lesser camera, and there is nothing wrong with that for the market they choose.

When you bracket two images by 1EV and open these two images with RawDigger, you would be able to notice that the levels around the same region in the frame are about 2:1 ratio between these two images. This means every 1 extra bit stores one extra stop of dynamic range. If the sensor can only capture 14 stops dynamic range, then 16-bit raw file would be overkill, and the lowest 2 bits would be just noise (useless information stored).

Your H3DII is a CCD sensor and has less than 12 stops of dynamic range. That means a raw file with more than 12-bit would be overkill for the H3DII, and anything beyond 12-bit is just for marketing/metaphysics without technical benefit.
« Last Edit: January 16, 2017, 11:06:56 PM by voidshatter »
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E.J. Peiker

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Re: 16 Bit Color for Hasselblad X1D but only 14 bit for Fuji GFX?
« Reply #13 on: January 17, 2017, 08:33:13 AM »

Hi,

This shows that desinformation works.

Dynamic range is range between highest reproducible white and lowest reproducible dark. Darks are always limited by noise.

Light, on it's own, is noisy. It is coming in quanta. A pixel can capture so and so many photons (quanta of light) your  sensor on the Hassy can hold around 60000 electron charges per pixel. Normally, an electron charge corresponds to a captured photon.

As I said, the light itself is noisy. If you would photograph a white piece of paper overexposing 3 EV for the white you would have around ETTR (Expose To The Right) exposure with the sensor fully utilised. In this the paper white would be represented by a bell curve, centered around 60000 with 65 of the pixels having between 59750 and 60250 electron charges.

Now, looking at the other end the Hasselblad sensor has a readout noise of around 10.5 e-, if I recall correctly. So the ratio between the Full Well and the readout noise would be 60000 / 10.5 -> 6190. If we will represent that range with a binary number it would need log(6190) / log (2) -> 12.5 bits. So that sensor is a barely 13 bit device.

To explain the difference between your Canon and Hasselblad you need to go somewhere else. One factor is that your Canon has fewer pixels and Canon has quite noisy readout, too. If you look at actual pixels you would see the noise at the pixel level. But at any other size the Hasselblad would use more pixels for each visible dot. That would reduce the noise. But not because it has more bits of data but because it has more pixels.

The major factors for colour rendition are in all probability two. One is the Color Filter Array. The pixels don't have colour, they just count photons. Colour is added by using a Color Filter Array.

The Kodak CCDs used to have quiet extreme CFA designs, probably optimised for studio light. Canon's are often used in mixed light and under poor light conditions. Their CFA designs are more general purpose and probably more permissive.

The other factor is the colour profile. The signal coming out of the sensor is a voltage, that is amplified and converted to binary data by an ADC, which happens to be a commercial flash converter older cameras.

The binary data is converted to RGB data using a colour profile. Hasselblad is known for well made colour profiles.

Later generation CMOS sensors have moved the ADCs to the sensor. There is normally thousands of them, one for each column. This allows to use slow but precise converters. But it also means that the vendor of the sensor decides the number of bits and the Sony sensor used by Fuji and Hasselblad is a 14-bit device.

The enclosed screen dump of the RawDigger histogram of a raw file from the X1D-50c clearly indicates that each fourth channel contains data. That the gaps also contain data indicates that some image manipulation has been done on the raw data. That could be flat field correction of the raw data, or simply some dither noise added.

The second screen dump is coming from an Phase One IQ350 shot, courtesy of Digital Transitions. This shows no sign of postprocessing in raw. Phase One also claims 16 bit colour. The IQ 350 uses the same Sony sensor as the X1D-50c

The last attachments shows the white patch on IQ 350 shot. It shows what a great spread of signal a single patch can have. Some of that may come from the rough surface of the patch, but most is coming from variation of incident photons.

Best regards
Erik

Exceptional explanation.  Thank you for taking the time to write it!
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Lust4Life

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Re: 16 Bit Color for Hasselblad X1D but only 14 bit for Fuji GFX?
« Reply #14 on: January 29, 2017, 04:45:49 PM »

Erik - Another great example of why, "When Erik speaks, I listen and don't question"!

Well explained my Ole Friend!

Jack

BobShaw

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Re: 16 Bit Color for Hasselblad X1D but only 14 bit for Fuji GFX?
« Reply #15 on: January 29, 2017, 06:40:23 PM »

There is more to a camera than the sensor alone.....
Cheers,
Bart
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BJL

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Re: 16 Bit Color for Hasselblad X1D but only 14 bit for Fuji GFX?
« Reply #16 on: January 29, 2017, 09:33:39 PM »

The sensor used by both these cameras does ADC onboard, outputting a digital signal, so I very much doubt that there is a difference in the number of _significant_ bits in their raw output. If indeed Hasselblad delivers 16 bits while Fujiifilm delivers only 14, it would be due to Hasselblad padding 14 bit sensor output with two zeroes to fit its previous practice of delivering 16 bit numbers (two full bytes), without their being more than 14 significant bits.
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Lust4Life

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Re: 16 Bit Color for Hasselblad X1D but only 14 bit for Fuji GFX?
« Reply #17 on: January 29, 2017, 09:35:31 PM »

The sensor used by both these cameras does ADC onboard, outputting a digital signal, so I very much doubt that there is a difference in the number of _significant_ bits in their raw output. If indeed Hasselblad delivers 16 bits while Fujiifilm delivers only 14, it would be due to Hasselblad padding 14 bit sensor output with two zeroes to fit its previous practice of delivering 16 bit numbers (two full bytes), without their being more than 14 significant bits.

Now that's a disturbing thought!

Stephen Scharf

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Re: 16 Bit Color for Hasselblad X1D but only 14 bit for Fuji GFX?
« Reply #19 on: January 30, 2017, 04:07:35 PM »

Why? It has bees done by Hasselblad and phase one before.


Gesendet von iPhone mit Tapatalk

Peronally, I'm not sure whether it has been done by Phase or HB before is the point; I think the point that BJL was making is whether it actually has any practical significance.
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