EOS-1D X Mark II Claims of 15 Stops of DR [CR3]

[LetTheRightLensIn]

When you really need lots of DR, 15 stops is not enough. DR is, however, basically a measure of noise, so lower noise means higher DR and better high ISO.

I do find this statement a bit odd, though I agree with some. When my camera clips highlights, and I try to expose for the highlights, making me raise the shadows, with noise and banding, the 11 stops of DR my sensor gives me is not enough. That does not make a 15 stop DR - sensor not necassary. Perhaps 13 stop would do in my case, which is still 2 stop more than I get from my current setup. Hence, a 15 stop sensor would be great, and more than enough.

Yeah what he meant is that if someone else does it better it doesn't matter since it's either not enough anyway, fake, whatever. But if Canon does it then it's great and helpful.

(for the record, from what I see from dappled forest photography that little extra bit he says is useless would actually very often be just enough to be totally helpful, maybe not absolutely ideal, but enough to make it work; and then those who say it still doesn't matter since HDR and tone mapping are ugly, well, first you can do careful types of tone mapping and tone certain ranges and areas apart and get a decent bit of HDR out it without it having that super HDR look at all and second HDR TV are starting to appear and in another 2 years most monitors and tvs produced will probably be 4k, ultra wide gamut, 10bit, HDR, at least other than for the least expensive stuff, the next generation disc format already states that video should be encoded as ultra wide gamut and HDR, I'm not sure they will make it, but the industry had set a goal to make all non-most basic displays be 4k, ultra wide gamut and HDR (and 10bit) by the end of 2018)

 

[PureClassA]

Hasn't it already been shown that Canon sensors could produce 15 stops of DR for a long time now?

It's really just a matter of extracting that 15 stops of DR and getting it into a file for the memory card, which they have not done as of yet.

Yes. That discussion was rehashed briefly earlier on this very chain in fact.

(1) Shorten the signal path (on Board ADCs). (2) Keep out the noise better than now (other patents Canon already has but yet unknown if they will be employed in the DX2), and (3) realize more of the natural DR of the sensor (like the 5D3 which has several stops more than we realize thanks to problems with 1 & 2 at present).

 

[zim]

(2D FFTs)

For those that don't understand 2D FFTs. The ideal response to an image of noise is a flat noise plane with a single white dot in the middle (representing the overall average rightness). Low frequencies are in the centre, high frequencies are towards the edge.

If there are dots or stripes in the FFT space then that means there are repeating patterns in the image space, even if you can't seem them, which is often the case.

appreciated, thank you

 

[zim]

ok I might have to delete this out of embarrassment but I've got to ask....

Does all this increased DR mean that a correctly exposed image which has DR within the bounds of the camera, so doesn't have to be pushed or pulled, at a high iso say 25600 would have less of the grainy stuff and look more like existing 12800 ?

 

[heptagon]

But 88Mb sensor and a 14bit ADC does not seems the way to me how Canon will get the 15 stops of DR.

Quad-Pixel-Phase-Detection-Focus?

 

[rfdesigner]

ok I might have to delete this out of embarrassment but I've got to ask....

Does all this increased DR mean that a correctly exposed image which has DR within the bounds of the camera, so doesn't have to be pushed or pulled, at a high iso say 25600 would have less of the grainy stuff and look more like existing 12800 ?

DR is only an issue at low ISO. Above about 1600 ISO Canon=Nikon=Sony (roughly)

What's happening is this: Sensor collects electrons -> amplified -> ADC -> stored in RAW format. If that Amplification stage adds noise (and it will to some extent) then it limits the range of brightnesses that can be accurately determined.

At High ISO the amplification is high, so the signal level at the beginning can be low.. making the camera sensitive. At low ISO the amplification is low, so now the camera can be sensitive to a much higher signal level without clipping the ADC.

If the whole system has the same apparent noise normalised to the sensor at low ISO and high ISO, then you can see that low ISO = wide range of signals = high DR. Roughly, this is what the sony sensors achieve. It's usually useful where you have a unshielded light soruce and you want not to blow that out whilst also show what it's illuminating.

i.e. sunset shots, indoor shots with the view outside being important to the shot too (& no flash) etc.

 

[Don Haines]

...
he's just trolling. everyone else is here having a pretty enlightening discussion on how it's unlikely that Canon has actually packed in 15 stops of DR, how it could be claimed through marketing nonsense/obfuscation, or how it could actually happen if Canon used the right technology and gave us 16-bit files.

You should have seen what people said when I tried to argue that Nikon/Sony did the same to squeeze more than 15 bits of DR into 14 bits. Everyone was adamant that it was not possible. The Canon fanboyism is high with this thread. If Canon marketing uses the term, everyone looks for ways to make it possible. If some other vendor does it then that other vendor is lying.

And this is the point that I was trying to raise.... if Canon (or Nikon or Sony) had managed to increase the DR of their sensors by two stops, then they are going to need extra bits to hold that increase in resolution. The easiest way to do this is to start saving 16 bit RAW files. If the 1DX2 does not have an appreciable gain in RAW bit depth, then it will not have an appreciable gain in real DR.

 

[heptagon]

ok I might have to delete this out of embarrassment but I've got to ask....

Does all this increased DR mean that a correctly exposed image which has DR within the bounds of the camera, so doesn't have to be pushed or pulled, at a high iso say 25600 would have less of the grainy stuff and look more like existing 12800 ?

No, high DR only plays a role at low ISO. High ISO cannot have high DR because there are only so few photons per pixel. Canon cameras already have little excessive noise at high ISO.

An image which is exposed "correctly" such that nothing has to be pushed or pulled does not need high DR. Do you know any display device that can display more than 10 stops of DR?

 

[Jack Douglas]

rfdesigner,

Thanks that's helpful. By analogy it's not unlike an analog audio signal - to low and it's lost in the noise as you amplify both noise and signal. Too high and it's clipping the signal and intelligible louder sounds are lost. Is that a reasonable comparison?

Jack

 

[Lee Jay]

An image which is exposed "correctly" such that nothing has to be pushed or pulled does not need high DR. Do you know any display device that can display more than 10 stops of DR?

All of them, including prints.

It's not hard to tone map 25 stops of DR into a 6 stop capable display system. If you go to the Hubble Site, you'll see a lot of that sort of thing going on. Many of those images (but not all) have absolutely huge DR, all mapped into an 8-bit JPEG.

 

[zim]

Thanks for the reply redesigned and heptagon. I get where the benefits lay now, I had just been wondering if there could have been higher ISO benefits.

Heptagon, no I don't all my output goes to print and photobooks ! ;D

 

[tpatana]

When Canon does a press release and says "15 stops of DR", everyone goes "wow, cool."...
And not only that, people are accepting Canon's "15 stops of DR" statements over testing that actually shows less.

Did you and I read the same thread?

15 stops at what resolution?

If on the single pixel level, that would truly be phenomenal!

If on a scaled down image of 1 Megapixel, that wouldn't be very impressive.

When you really need lots of DR, 15 stops is not enough. DR is, however, basically a measure of noise, so lower noise means higher DR and better high ISO.

One more claim I'm not sure I'd believe completely. Hoping for best of course, but...

etc

I was wondering exactly same. Then I saw who wrote that. Not first time he's writing in his own bubble.

 

[sanj]

I do find this statement a bit odd, though I agree with some. When my camera clips highlights, and I try to expose for the highlights, making me raise the shadows, with noise and banding, the 11 stops of DR my sensor gives me is not enough. That does not make a 15 stop DR - sensor not necassary. Perhaps 13 stop would do in my case, which is still 2 stop more than I get from my current setup. Hence, a 15 stop sensor would be great, and more than enough.

Mt. Spokane's description fits my experience perfectly. I shoot with the 5DIII and I run into 2 types of "DR" issues. The first is bright sun and shadows. This far exceeds 10-15 stops DR. In other words, expose for the shadows and blow out the part of the frame in full light. Expose for the bright light and the shadows are completely dark. An additional stop or two of DR will not help me in this circumstance.

But, the other time I run into DR is noise in the blacks/shadows. This can be in astro or a few other situations, like with a background behind a waterfall. I do not run into it often (you know, proper exposure), but occasionally I see some shadow noise. Here, simply cleaning up noise in the blacks/shadows will help my images and expand DR by 1-2 stops. From what I've gathered over the years on this forum and others is that the primary cause of this issue is noise that is gained as the analog signal moves from the chip to off the chip before being converted to a digital signal, thus, the hope is that on chip A/D converters would minimize this noise and the issue with black/shadow noise.

My go-to lens is the Sigma 35mm ART.


Simplistic, but that is my level of understanding. If others know better, please expand.

Usually my problems start when I take pictures of the kids outside in the afternoon. Low sun, not too bright outside, and quite fast moving subjects. Perhaps ISO 800 to get the shutter speed right. DR is a problem then. Either blown highlights or misserable shadows. A few more stops of DR (esp. at ISO above base 400-3200) would be great.

Yes!

 

[neuroanatomist]

An image which is exposed "correctly" such that nothing has to be pushed or pulled does not need high DR. Do you know any display device that can display more than 10 stops of DR?

All of them, including prints.

It's not hard to tone map 25 stops of DR into a 6 stop capable display system. If you go to the Hubble Site, you'll see a lot of that sort of thing going on. Many of those images (but not all) have absolutely huge DR, all mapped into an 8-bit JPEG.

That doesn't answer the question.

 

[Jack Douglas]

An image which is exposed "correctly" such that nothing has to be pushed or pulled does not need high DR. Do you know any display device that can display more than 10 stops of DR?

All of them, including prints.

It's not hard to tone map 25 stops of DR into a 6 stop capable display system. If you go to the Hubble Site, you'll see a lot of that sort of thing going on. Many of those images (but not all) have absolutely huge DR, all mapped into an 8-bit JPEG.

I don't have a firm handle on this so may be displaying ignorance. When the human eye views a scene where there is bright sun somewhat in the field of view and deep shadows as well, it does not perceive all the detail in the highest brights and the lowest darks. To me, looking at some HDR photos that were bragged up, I felt they just looked "unnatural". Is that what we're after, being able to distinguish detail in the darkest and brightest areas even though it doesn't represent reality?
This is just an innocent question. Isn't mapping just another way of saying compression?

Jack

 

[sanj]

ok I might have to delete this out of embarrassment but I've got to ask....

Does all this increased DR mean that a correctly exposed image which has DR within the bounds of the camera, so doesn't have to be pushed or pulled, at a high iso say 25600 would have less of the grainy stuff and look more like existing 12800 ?

No, high DR only plays a role at low ISO. High ISO cannot have high DR because there are only so few photons per pixel. Canon cameras already have little excessive noise at high ISO.

An image which is exposed "correctly" such that nothing has to be pushed or pulled does not need high DR. Do you know any display device that can display more than 10 stops of DR?

Not my experience.

 

[sanj]

An image which is exposed "correctly" such that nothing has to be pushed or pulled does not need high DR. Do you know any display device that can display more than 10 stops of DR?

All of them, including prints.

It's not hard to tone map 25 stops of DR into a 6 stop capable display system. If you go to the Hubble Site, you'll see a lot of that sort of thing going on. Many of those images (but not all) have absolutely huge DR, all mapped into an 8-bit JPEG.

I don't have a firm handle on this so may be displaying ignorance. When the human eye views a scene where there is bright sun somewhat in the field of view and deep shadows as well, it does not perceive all the detail in the highest brights and the lowest darks. To me, looking at some HDR photos that were bragged up, I felt they just looked "unnatural". Is that what we're after, being able to distinguish detail in the darkest and brightest areas even though it doesn't represent reality?
This is just an innocent question. Isn't mapping just another way of saying compression?

Jack

Jack my understanding is that our eyes look at one thing at a time so when at a sunset when we look at the bright clouds our eyes adjust to show details and when we look at the darkness under the trees our eyes adjust. We can do this very rapidly and in effect have a very hight DR built in.

 

[JoseB]

A color of a pixel is defined by --> R(14 bit), G(14bit), B(14bit) -> total 42 bit.

About the non linear sampling, remember the old vinil music records, that to fit the frequency range in a thin groove, the basses are attenuated and the trebles are expanded during recording following a RIAA curve.
When playing, the signal was restored by one amplifier stage, with the help of a couple of capacitors and resistors. Here applying an inverted RIAA amplification curve. The basses were expanded and the trebles attenuated.
It provided also the reduction of the noise in the high frequencies.
It could be done similarly to the analog signal extracted from the pixels, before the ADC.
I think.

 

[neuroanatomist]

To me, looking at some HDR photos that were bragged up, I felt they just looked "unnatural".

shad·ow. ˈSHadō/ noun
1. a dark area or shape produced by a body coming between rays of light and a surface.

Your brain sort of expects shadows to be...dark. When they're not dark, and there's no obvious reason for that, it naturally looks unnatural. Naturally.

 

[Diltiazem]

An image which is exposed "correctly" such that nothing has to be pushed or pulled does not need high DR. Do you know any display device that can display more than 10 stops of DR?

All of them, including prints.

It's not hard to tone map 25 stops of DR into a 6 stop capable display system. If you go to the Hubble Site, you'll see a lot of that sort of thing going on. Many of those images (but not all) have absolutely huge DR, all mapped into an 8-bit JPEG.

I don't have a firm handle on this so may be displaying ignorance. When the human eye views a scene where there is bright sun somewhat in the field of view and deep shadows as well, it does not perceive all the detail in the highest brights and the lowest darks. To me, looking at some HDR photos that were bragged up, I felt they just looked "unnatural". Is that what we're after, being able to distinguish detail in the darkest and brightest areas even though it doesn't represent reality?
This is just an innocent question. Isn't mapping just another way of saying compression?

Jack

There are several aspects to your question.
1. The fact that you have asked this question says something about most people taking pictures. Most people simply don't lift shadows or feel the need to do it or know that it can be done.
2. Most people who lift shadows overdo it and make their picture look 'unrealistic'.
3. In a high contrast scenes our eyes adjust to both bright and dark areas. So, if you expose for bright areas, dark areas might get darker in the image than how we actually see. So, shadow lifting maybe needed in these situations to make a picture look realistic (not necessarily look better).
4. Exmor and other non-Canon sensors are better in shadow lifting, although none of them are perfect. So, a better technique at the moment is to blend multiple exposure. But there are situations where blending is not an option, so better shadow characteristics is always welcome.