16 Bit Myth

[BernardLanguillier]

Marc McCalmont, one of the frequent posters on this forum, posted raw image from his K5 and his P45. My understanding is that he felt that the K5 had better image quality.

At least it seems pretty clear that the 5DII, although it is a very successful camera widely used by pros, is now pretty far being the best DSLRs available.

So measuring the gap between backs and DSLRs by using the 5DII as a reference seems a bit unfair.

Cheers,
Bernard

[hjulenissen]

A great suggestion but:
- I don't agree that the DXO measurements fully explain the useable range captured (two raw files can have a similar measure but in one the shadows are clumpy, tonally choppy, and inaccurate in color while the other is gaussian/film-like, tonally smooth, and accurate in color - the difference between quantitative engineering measurement and qualitative photographic aesthetics)

We cannot always quantify that which we feel is true. In those cases, instead of resorting to "amazing true (tm) 16-bit quality", I would prefer statements such as "used by professionals world-wide", or "in a side-by-side comparision on luminous-landscape.com, 42 out of 51 voters preferred the X camera over Y".

-h

[ErikKaffehr]

Hi Bernard,

I don't get your point K5 is Pentax K5. I update the posting to be more clear on the issue.

Anyway, Marc posted  comparable raw images from his P45 (Phase One) and K5 (Pentax). Highlight detail was similar but shadow detail was much better on the Pentax.

Best regards
Erik

At least it seems pretty clear that the 5DII, although it is a very successful camera widely used by pros, is now very far being the best DSLRs available.

So measuring the gap between backs and DSLRs by using the 5DII as a reference seems a bit unfair.

Cheers,
Bernard

[Bryan Conner]

Can I assume that you've never dealt with us (Capture Integration) as a customer before?

Doug Peterson (e-mail Me)
__________________

Head of Technical Services, Capture Integration
Phase One Partner of the Year
Leaf, Leica, Cambo, Arca Swiss, Canon, Apple, Profoto, Broncolor, Eizo & More

National: 877.217.9870  |  Cell: 740.707.2183
Newsletter | RSS Feed
Buy Capture One 6 at 10% off

You are correct.  I have never dealt with you before.  I  intended no slight on you or your service.  My point is that I do not think that with a level of quality that both you and your products exhibit, that you need to spin the truth at all.  I apologize if I was not clear with my intention.

[BernardLanguillier]

bits of cold... after a bit of editing.

[ErikKaffehr]

Hi,

Nice for you to have some winter in Japan, we don't have any here is Sweden.

You have sold your D3X? What are you using now?!

Best regards
Erik

bits of cold...

[BernardLanguillier]

Hi,

Nice for you to have some winter in Japan, we don't have any here is Sweden.

You have sold your D3X? What are you using now?!

An IQ180.

Kidding, a D7000. Very nice little camera I have to say. Works wonders when stitching.

Cheers,
Bernard

[deejjjaaaa]

You are correct!  So, does this mean that the modern MF digital backs, that are advertised to be 16 bit, are not capable of producing files of the same (or better) quality as the Pentax K10D from 2006?

Pentax had a decency to stop.

[theguywitha645d]

Again, I'm open for suggestions.

The problem to be solved is explaining that the 22mp files from this camera have better tonal smoothness and better ability to hold up to post processing than the 5DII that 90%+ of our potential clients assume is the same because it also has 22ish megapixels. That must be done in about 15 characters and in a way that 90% of people viewing the ad will understand instantly and without further (immediate) explanation (they can of course always ask for more details when they contact us).

Brainstorming here:
"Large Sensor"
"Flexible Raw File"
"Great Tones"
"Smooth Tones"
"Beautiful Files"

None of those strike me as a great substitution. But if ya'll feel strongly one of them does a better job solving the marketing problem outlined above let me know.

How about:

Professional IQ
Amazing IQ
Commercial IQ
Medium-format IQ
5D Killer
Can't believe it ain't 16-bit

I would go for "large sensor" or "2X the 35mm area" or whatever the area difference is or simply the sensor dimensions. One phrase on an ad is not going to sell this back. I would imagine the customer who is coming to you is more interested in the sensor size anyway--or why go to MFD? Believe it or not, but I will not buy this back on a simple ad. I think the word that is going to get the customer to call you is "affordable."

[BJL]

Again, I'm open for suggestions.

The problem to be solved is explaining that the 22mp files from this camera have better tonal smoothness and better ability to hold up to post processing ... That must be done in about 15 characters and in a way that 90% of people viewing the ad will understand instantly and without further (immediate) explanation

Brainstorming here:
"Large Sensor"
...

That first suggestion is probably the main root cause, but how about

More pixels for higher PPI printing and smoother tonal dithering

given that I see no evidence of a per pixel advantage for DMF backs over the state-of-the-art from Sony and such.

However, this slogan assumes that people paying four figure prices for digital cameras know a bit about dithering and such, which I think they should, but ...

You could also talk about the inherent larger format lens performance advantages, in lp/ph resolution and such, but that seems out of fashion!

P. S. I added "smoother tonal" to my slogan, since that seems to be a selling point of interest to you.

[Guillermo Luijk]

Surely, the ISO values of >1600 tend to be obtained by digital multiplication, at least in Canon cameras?

My point was that perhaps also 1/3 stop intermediate ISO values are obtained by multiplying a limited number of analog gain values by 4/3, 2/3 etc?

In older Canons ISO3200 and above was obtained from ISO1600 multiplied before encoding RAW data. In some newer ones that happens from ISO6400. In any case ISOs above ISO1600, no matter if they are analogue or digital, don't add anything to the RAW shooter because SNR doesn't improve anymore.

By processing I meant applying noise reduction on the RAW data. The digital ISOs (and this includes +1/3 and +2/3 values) are of no interest to the RAW shooter.

[HCHeyerdahl]

Again, I'm open for suggestions.

The problem to be solved is explaining that the 22mp files from this camera have better tonal smoothness and better ability to hold up to post processing than the 5DII that 90%+ of our potential clients assume is the same because it also has 22ish megapixels. That must be done in about 15 characters and in a way that 90% of people viewing the ad will understand instantly and without further (immediate) explanation (they can of course always ask for more details when they contact us).

Brainstorming here:
"Large Sensor"
"Flexible Raw File"
"Great Tones"
"Smooth Tones"
"Beautiful Files"

None of those strike me as a great substitution. But if ya'll feel strongly one of them does a better job solving the marketing problem outlined above let me know.

As a person considering the jump to MF, my take is that your marketing ought to reflect reality. Thing is when you quote 16 bit as something that makes MF stand out from FF DSLRs,  and threads on several forums find this questionable, I as a potential customer begin to wonder if the whole thing is snake oil. I have spent quite some time trying to sort this out and I am not finished yet...

Now, from what I have managed to pick up from numerous threads it may appear that it is the very size of the sensor itself AND coupled with stricter tollerances in every component that gives MF its alleged superior image quality. If this is actually the case, then this is VERY interesting for a potential customer since this will not be available in a future FF DSLR. Of course DSLRs will continue to evolve, but they will not grow bigger sensors. I also find it unlikely that they will increase their quality tollerances. Hence, at a given purchase date, the benefits from a MF investment will probably hold itself against future FF DSLRs for more than one or two generations (btw a great  wife argument!).

I really don´t have a ready 15 char slogan for you but something along the line of "Built to MF quality tollerances" , "Designed for MF quality" would at least to me suggest that the quality of MF has someting to do with the quality of the entire system.  Sure, lots of people will contest this or similar assertions, but at least we will not have threads from people with superior technical knowledge in image processing, etc more or less PROVING your (16 bit) advantage is wrong.

Hay, OK !  Maybe I still haven´t got it - just my two (amaturish) cents trying to be helpful  .

Christopher

[Slobodan Blagojevic]

... the inherent larger format lens performance advantages, in lp/ph resolution and such, but that seems out of fashion!...

Back in the film days (i.e., the last time I was paying attention to this), larger format lenses were, if anything, inferior to 35mm format lenses in terms of lp/mm resolution. However, given the need for less magnification, they could get away with it and still end up with superior results in print. Is the situation different nowadays with digital?

[fredjeang]

It seems to me that a something important is often missing in those discussions that involve tech.

Yes, a MF lens is normally inferior but with digital the need for less "vague" standards is important, for MF as for 35 or m4/3 or even the newest Nikon standard.

So teorically, a lens that has been designed for film, with much more "room" than digital allows, should performs so so on a digital camera.

But reality shows that it's far from being a golden truth.

The missing part for me, is that I rarely hear talking about light. Light knowledge, understanding, is all. It's key. Everybody is concern about sharpness and resolution, so all the factors that are the less relevant when it comes to imagery.

Most of the time you see people that are following lenses and sensor testings-specs. But each lens is a word in itself and they would exell under certain light conditions. This understanding is too often missed. I have a 30 euros russian pancake lens call Industar. It's a plastic lens. It can be extremely bad, or, if you learn how to use it and in wich conditions it shines, it can be very good.

And yeah, it's not a glamour lens, it won't impress the gallery. But I know at least one international photographers that uses it for B & W outputs.

Remember when Graham did a testing with Rollei vintage lens on a IQ back? Did it lacked sharpness and resolution?

I strongly recommend to have a look on Cooter's and mark Tucker websites.

I spent all yesterday afternoon with Mark tucker's blog that I hadn't visited for some time and it was a pure delight. He shoots with everything, and he bloody knows what he is doing. More importantly, he catches you.
Mark Tucker couldn't care less about image chirurgical precision, in fact it's like he escapes the trap on purpose and he obviously knows very well about MF LF and digital retouching. (I'm not talking for him but that's the sensation he transmits) I saw some movies he did and yeah, content is king.
Then i visited some Coot movies too, I was blowned again by the car race, high isos, grainy, not ultra sharp, blowned highlights on purpose (where is the DR so many people are concern with?) but what a great peice of motion! It gave me some enthousiasm and boost to persevere into motion.
When tech parameters enter into consideration, is that the image missed the point.


Shoot with whatever my friends, in any bits, byts bites.

[BJL]

Back in the film days (i.e., the last time I was paying attention to this), larger format lenses were, if anything, inferior to 35mm format lenses in terms of lp/mm resolution. However, given the need for less magnification, they could get away with it and still end up with superior results in print. Is the situation different nowadays with digital?

Indeed: that is why I mentioned lp/ph (line pairs per picture height) to compensate for format size differences. Also, it seems that in recent years, there have been some stunningly sharp new lenses designed for DMF, at least from the large format lens makers (Rodenstock et al) getting into the digital back market. Does anyone have some up-to-date data on something like lp/ph at MTF50 for various 35mm and MF lenses (assuming 48x36mm in MF, for example, so a gain for DMF by a factor of 1.5 relative to lp/mm comparisons.)

[ErikKaffehr]

Hi,

It depends. What it depends on is the MTF of the lens and the sensor at the frequency we are interested in. The frequency is given by viewing distance, the contrast sensitivity of the eye and the magnification. Once the frequency is known we multiply MTF for lens and sensor for that frequency.

This is what is called SQF, essentially. Well SQF is actually the integral over the contrast sensitivity function of the eye, but...

With digital things have shifted a bit. We have medium and large format lenses specially built for digital. Some of those lenses (Schneider,  Rodenstock HR digital lenses and lenses for the Leica S2) may be better than the best 135 lenses.

My feeling right now is that the best lenses outperform the sensors. Once we see aliasing or moiré that is a sure sign of that.

Best regards
Erik

Back in the film days (i.e., the last time I was paying attention to this), larger format lenses were, if anything, inferior to 35mm format lenses in terms of lp/mm resolution. However, given the need for less magnification, they could get away with it and still end up with superior results in print. Is the situation different nowadays with digital?

[ixania2]

If you would advertise your own products this way, you would go bancrupt soon, believe me.

That first suggestion is probably the main root cause, but how about

More pixels for higher PPI printing and smoother tonal dithering

given that I see no evidence of a per pixel advantage for DMF backs over the state-of-the-art from Sony and such.

However, this slogan assumes that people paying four figure prices for digital cameras know a bit about dithering and such, which I think they should, but ...

You could also talk about the inherent larger format lens performance advantages, in lp/ph resolution and such, but that seems out of fashion!

P. S. I added "smoother tonal" to my slogan, since that seems to be a selling point of interest to you.

[telyt]

Again, I'm open for suggestions.

If you say much more than "Lots of people like 'em" someone's going to get his knickers twisted into knots.  Or maybe they will anyway.

[BrendanStewart]

http://en.wikipedia.org/wiki/Quantization_(signal_processing)

Can't translate the url, paste this: en.wikipedia.org/wiki/Quantization_(signal_processing)

I suggest this as interesting reading as well. The images are particularly useful in showing why signal resolution is important.

[Fine_Art]

What implied advantage?  There is no implication from a 16 bit A/D converter to more tonal smoothness.  There are many other factors that are responsible for that quality.  

With a read error of 2e for the Exmor sensors, not to mention a higher QE, I'd say they are.  Otherwise, I'd expect to see your MF sensors perform nicely at ISO 6400, without Sensor+.  

There are lots of good reasons to buy your products, true reasons.

I've been led to expect only one thing: that there are 16 bits of beneficial image information to be gained by buying your camera.  Well, is there or isn't there?  

Reductio ad absurdum argument: Why not have 24 bit A/D converters and advertise that?  If people are led by that -- falsely -- to expect better tonality and file robustness, they have surely not been misled?  Either there is a benefit or there isn't, and if you are implying that there is one when there isn't, you are culpable.  

True as opposed to what?  

The Pentax K10D had a 22 bit DA converter. It was dumped in the newer cameras for 14 bit versions. All reviews say the newer cameras produce better pictures despite the less expensive DA converters.

Another issue is there is no current technology to view 16 bits. If you look at the websites of LCD manufacturers you will see they are mostly 10 bit devices with some 12 (There may be 14 since the last time I looked) for very expensive hospital devices. Everything over the 10 bits is dithering of adjacent pixels. Yes, your OS claims you have 32 bit color. Prints have even less dynamic range.

Despite that I would still prefer a camera that could record a full 16 bits for future screen technology. Some shots cannot be redone. A full 16 bit pipe from sensor to file is a good thing. My camera does multishot HDR very well, the files look good. Unfortunately it only outputs this to 8bit jpg. Doh! Now why cant they combine multishot into a full 16bit RAW?