Just for Jrista: 2014 Market Data

[sarangiman]

I've never been quite comfortable with the results from the A7 I have now pushed any more than 4 stops. Then again, I never push my 5D3 shadows more than a stop without using MagicLantern.

Interesting. Actually, thanks for this data point. I was mildly considering getting rid of my A7R and getting the A7 instead, b/c of shutter shock on the A7R which makes the 70-200 FE of limited utility, and b/c phase detection on the A7 actually helps nail focus faster, and even track to a certain degree. AF-C shouldn't even be offered on the A7R, in my opinion, but that goes without saying for most CDAF-only systems.

But now your concern added with the slightly worse ISO performance according to both DPR studio scene and DxO makes me think I'll ditch the A7 system altogether until Sony introduces a model with electronic first curtain in the 36MP sensor (and hopefully stops compressing their RAWs).

The spikey behavior in the histogram represents posterization. This isn't even really a function of the sensor at all, just that we don't have enough information to provide continuous color contours. It's not going to appear as clearly as your exampe though due to the random noise. In any case, Sarangiman clarified that he meant that higher ISOs were emulated with higher base ISO rather than always sticking with ISO 100 which, surprisingly to me, actually makes a huge difference.

Yeah, but then you could call the A7S 'posterized' at ISO 409k, where it's trying to make an image with ~50 photons or less per pixel (50 photons = white), according to sensorgen's back-calculations. At least it's dithered. But yes what you're talking/worried about is a form of quantization error, since at ISO 100 you're not counting every electron. This'd be largely fixed with a 16-bit ADC, though. So hopefully we'll see those soon in Sony/Nikon cameras.

And I think by ISO 400 you're counting every electron, which is why you see a difference. You're also amplifying even the lowest signal 4x, so that may be just enough to make it less affected by the 2-3 electrons (my guesstimate) of downstream read noise that even Exmor sensors have.

The whole point was that even Exmor RAW files can't be pushed 6 stops without trouble.

Er, I'm going to have to beg to differ. Here's the D810 at ISO 6400 and at ISO 100 pushed 6 EV:

Can you tell which is which?

Btw, in the ISO 100 file, that road has a signal of average 7 for the green channel, where the SNR is 3.5. Red channels is like 4. These are all on a 16-bit scale. So pixels with signals of literally 4-7 in the Raw file (1 being minimum, ~16,000 being maximum).

So I'm not even talking about pushing a midtone or even a shadow +6 EV. I'm talking about pushing some of the deepest of the deep shadows 6 EV. With brighter tones - you can't tell *any* difference between ISO 6400 and ISO 100 pushed 6 stops. But here even with tones all the way down at the floor of the sensor/Raw file, it's hard to see the difference. If that doesn't wow you...

Point being: yes you can push 6 stops for certain Exmor sensors. Though it does get tricky with ACR, since it's not really built to do that. I had to use the 'Blacks' slider which ends up reducing contrast, and I adjusted until I got the same brightness in the road as the ISO 6400 file.

 

[raptor3x]

Er, I'm going to have to beg to differ. Here's the D810 at ISO 6400 and at ISO 100 pushed 6 EV:

Can you tell which is which?

Btw, in the ISO 100 file, that road has a signal of average 7 for the green channel, where the SNR is 3.5. Red channels is like 4. These are all on a 16-bit scale. So pixels with signals of literally 4-7 in the Raw file (1 being minimum, ~16,000 being maximum).

So I'm not even talking about pushing a midtone or even a shadow +6 EV. I'm talking about pushing some of the deepest of the deep shadows 6 EV. With brighter tones - you can't tell *any* difference between ISO 6400 and ISO 100 pushed 6 stops. But here even with tones all the way down at the floor of the sensor/Raw file, it's hard to see the difference. If that doesn't wow you...

Point being: yes you can push 6 stops for certain Exmor sensors. Though it does get tricky with ACR, since it's not really built to do that. I had to use the 'Blacks' slider which ends up reducing contrast, and I adjusted until I got the same brightness in the road as the ISO 6400 file.

That's extremely impressive. I'd guess the one on the left was pushed with some shadow tint correction since it looks a bit green on this monitor but that's very good. The A7 is much noisier under similar conditions.

 

[sarangiman]

You both are correct. Well done!

And I'm glad you agree it's impressive. The D800 did the same, and the A7R is close. There are others as well. The D810 is particularly impressive b/c it'll eat up approx. 2/3 EV more exposure than ISO 100 before clipping, giving you even cleaner shadows (well, cleaner everything really, but it's of course most noticeable in shadows). Assuming you can throw the extra exposure at it (e.g. you're shooting on a tripod).

See we all learned something here.

 

[Khalai]

This is getting quite surreal and ridiculous at the same time. Pushing exposure 4 to 6 stops. That's pure madness (meant in a good way).

But I think it's somehow lost the good old "getting it right in the camera/on the spot" and that feels sad. How many situations are out there to justify pushing the shadows so much on regular basis. I'm not against progress at all and would love to have the latitude of Exmor as well, but this seems to make people lazy and sloppy, not caring about correct exposure IMHO.

 

[sarangiman]

This is getting quite surreal and ridiculous at the same time. Pushing exposure 4 to 6 stops. That's pure madness (meant in a good way).

But I think it's somehow lost the good old "getting it right in the camera/on the spot" and that feels sad. How many situations are out there to justify pushing the shadows so much on regular basis. I'm not against progress at all and would love to have the latitude of Exmor as well, but this seems to make people lazy and sloppy, not caring about correct exposure IMHO.

Understanding exactly how your camera works, and how you can push it to expand your work is not 'lazy and sloppy'. You can still use a reflector, for example, for fill if you want. But you have the option of not, and of not having to stop down, and the option to worry about nailing focus instead, or capturing the moment before your subjects get bored or before the rain starts pouring on them and you have to call it quits (actually what happened in the wedding shot I posted a crop of earlier).

Also, I don't think it's lazy to do SNR analyses to figure out exactly how much pushing you can do, what ISOs are better than others for pushes, and how you can use that information to gain highlight headroom without noise costs when you need it.

If anyone here honestly feels that photographers in fast-paced shooting scenarios don't already have enough to worry about with focus, picking the focus point, selecting the right lens for the composition, optimizing the composition, choosing shutter speed, aperture, ISO, placement of subjects, capturing the action, etc., then, yes, we're on totally separate planets. Removing the need to constantly worry about any one of those attributes is a noble goal.

You still have to know enough about exposure to get ETTR right, else you run the risk of unnecessarily paying a noise cost similar to what you'd pay with shooting at a higher ISO (something most photographers would want to avoid). And you still have to create interesting lighting on the spot; you can't magically add Rembrandt lighting b/c of Exmor. Basically, you end up spending more time and effort worrying about other things. Not become lazy and sloppy.

One day we'll have cameras that actively record what our eyes see, from which we extract whatever we want. Will that be the height of laziness, or will it force photographers to find creative ways to add unique value?

Anyway, this sort of stuff could be debated to no end.

 

[Sporgon]

This is getting quite surreal and ridiculous at the same time. Pushing exposure 4 to 6 stops. That's pure madness (meant in a good way).

Your not alone in thinking that. Once those missionaries that preach Exmor start talking about pushing six stops I think we can all relax in our heathen ways.

When I can snap straight into the sun and produce this image from one exposure with the Canon, who gives a damn ? I know I don't. The push/pull in this was about 2 stops.

 

[AmselAdans]

The future of photography... only ISO 100 setting, shutter speed always 1/1000, narrow aperture, fix focus length, object distance set to hyperfocal distance and then you shift the exposure in post just as you like.

"But I wanted only this small bird to be in the fram.."CROP IT WITH PHOTOSHOP
"But I wanted to have motion blu.."PHOTOSHOP!
"But..but...I want a longtime expo.."PHOTOSHOP!
"But..where is the Boke.."PHOTOSHOP!

and then we realize that the these new glory cameras will somehow ressemble the good old "Canomatic" cameras. Just with better MP and DR. Which is basically all we need.

 

[privatebydesign]

Er, I'm going to have to beg to differ. Here's the D810 at ISO 6400 and at ISO 100 pushed 6 EV:

Can you tell which is which?

Well other than them both being unusably bad, I'd say the 100 iso plus lift was the left, because it is noticeably badder than the one on the right.

So it seems we are really talking about the differences between realistic 3 stop lifts and unusable 6 stop lifts from any sensor.

 

[sarangiman]

Er, I'm going to have to beg to differ. Here's the D810 at ISO 6400 and at ISO 100 pushed 6 EV:

Can you tell which is which?

Well other than them both being unusably bad, I'd say the 100 iso plus lift was the left, because it is noticeably badder than the one on the right.

So it seems we are really talking about the differences between realistic 3 stop lifts and unusable 6 stop lifts from any sensor.

'Noticeably badder' vs. 4 people so far saying 'that's really impressive'.

Interesting.

If only there were a way to actually quantitatively, objectively measure the difference. Oh, right, there is. SNR measurements indicate very little difference between the two, actually.

And of course they're both bad - you generally try to avoid ISO 6400 levels of light, if possible. That's entirely irrelevant to the discussion, which is about high ISOs vs. pushed lower ISOs (the latter will never have better quality than the corresponding high ISO shot).

Sporgon - nice shot, but I can't actually tell noise levels in a 0.37 MP image. Also, I prefer not to have horizons that blown, but that's just me.

 

[privatebydesign]

Er, I'm going to have to beg to differ. Here's the D810 at ISO 6400 and at ISO 100 pushed 6 EV:

Can you tell which is which?

Well other than them both being unusably bad, I'd say the 100 iso plus lift was the left, because it is noticeably badder than the one on the right.

So it seems we are really talking about the differences between realistic 3 stop lifts and unusable 6 stop lifts from any sensor.

'Noticeably badder' vs. 4 people so far saying 'that's really impressive'.

Interesting.

If only there were a way to actually quantitatively, objectively measure the difference. Oh, right, there is. SNR measurements indicate very little difference between the two, actually.

And of course they're both bad - you generally try to avoid ISO 6400 levels of light, if possible. That's entirely irrelevant to the discussion, which is about high ISOs vs. pushed lower ISOs (the latter will never have better quality than the corresponding high ISO shot).

Sporgon - nice shot, but I can't actually tell noise levels in a 0.37 MP image. Also, I prefer not to have horizons that blown, but that's just me.

It would be impressive if I was still doing surveillance work for divorce cases, but I don't; it is impressive from a technical level if you are interested in technology, but I'm not really; it would be impressive if I could use either, but I couldn't. They are both unusably bad so it doesn't impress me. "Really impressive" doesn't equal usable, if I can't use it it won't impress me.

As for the SNR measurements indicating there is little difference, well what difference does that make when there clearly is? The one on the right has much more tonal gradation, it is like chalk and cheese, if you can't see the differences then I can understand why you are thinking it is impressive.

But that's just me.

 

[Kahuna]

Er, I'm going to have to beg to differ. Here's the D810 at ISO 6400 and at ISO 100 pushed 6 EV:

Can you tell which is which?

Btw, in the ISO 100 file, that road has a signal of average 7 for the green channel, where the SNR is 3.5. Red channels is like 4. These are all on a 16-bit scale. So pixels with signals of literally 4-7 in the Raw file (1 being minimum, ~16,000 being maximum).

So I'm not even talking about pushing a midtone or even a shadow +6 EV. I'm talking about pushing some of the deepest of the deep shadows 6 EV. With brighter tones - you can't tell *any* difference between ISO 6400 and ISO 100 pushed 6 stops. But here even with tones all the way down at the floor of the sensor/Raw file, it's hard to see the difference. If that doesn't wow you...

Point being: yes you can push 6 stops for certain Exmor sensors. Though it does get tricky with ACR, since it's not really built to do that. I had to use the 'Blacks' slider which ends up reducing contrast, and I adjusted until I got the same brightness in the road as the ISO 6400 file.

That's extremely impressive. I'd guess the one on the left was pushed with some shadow tint correction since it looks a bit green on this monitor but that's very good. The A7 is much noisier under similar conditions.

Impressive? If you CR members can make money off photo's like this congratulations and I admit I'm an idiot and should take up another hobby (maybe lawn bowling/or maybe BINGO) else they are crap.

 

[Aglet]

Sporgon - nice shot, but I can't actually tell noise levels in a 0.37 MP image. Also, I prefer not to have horizons that blown, but that's just me.

+1
could've retained more color near the horizon by reducing exposure and bring up the rest a bit more IF you had shot that with an Exmor. Not that you HAVE to, it would just provide you with that option, should you choose to use it.

 

[privatebydesign]

What's impressive is that is a SIX STOP push. That's the noise levels SIX STOPS deep in the exposure. Imagine what that means for shadows only two or three stops deep. It means they are PHENOMENAL.

I challenge anyone here who thinks a Canon can come even remotely close to that level of quality in the same situation with a 3-stop push to try. It isn't impressive from an artistic standpoint, or a money making standpoint (although having that kind of capability can only mean your a more capable photographer with fewer limitations, so that could affect the bottom line for a pro).

It is impressive from the standpoint of what it means for much more mild and realistic pushes when you need them, which DOES affect the end artistic result.

Do you honestly believe you can't push Canon files three stops?

 

[weixing]

Hi,
Look like every thread in CR will "evolve" to a DR thread somehow and sometime in the future...

Example of Evolution of DR thread: from "Market Data" thread to DR thread... ;D

Have a nice day.

 

[privatebydesign]

It depends on the exposure...and if your exposure isn't utilizing all the DR of a Canon sensor, then sure, you can push three stops, even more if you have ETTRed. The point here is, the limits with an Exmor are clearly WAAY deeper into the utter depths of the shadows than what is possible with a Canon sensor. I never expect to lift an image by six stops...however knowing that there is such little noise in shadows that deep tells me that I could lift mildly, and the shadows would still be pristine.

I don't follow, either you can lift three stops or you can't, where the highlights are is not in question, ETTR is not in question; were the lifted portions of the image, specifically shadows, lifted three stops and maintained any kind of image quality, that is the question.

Do you believe a Canon sensor, from the current generation, can be lifted three stops and still maintain good quality shadow detail, lack of noise and banding?

 

[sarangiman]

It would be impressive if I was still doing surveillance work for divorce cases, but I don't; it is impressive from a technical level if you are interested in technology, but I'm not really; it would be impressive if I could use either, but I couldn't. They are both unusably bad so it doesn't impress me. "Really impressive" doesn't equal usable, if I can't use it it won't impress me.

OK, but this is also kind of dissing the use of ISO 6400.

I wouldn't use it either, as I try to keep my ISOs pretty low, or otherwise use off-camera lighting. But I don't go around dissing the idea of high ISOs. You may as well just diss everyone that bought an A7s for its advantages over most other FF cameras over ISO 12,800 (but not much advantage below).

The only way to drastically improve ISO performance at this point is to increase sensor size. You could increase quality of shadows in the pushed ISO 100 file also by increasing FWC - which is essentially what Nikon has done in the D810.

As for the SNR measurements indicating there is little difference, well what difference does that make when there clearly is? The one on the right has much more tonal gradation, it is like chalk and cheese, if you can't see the differences then I can understand why you are thinking it is impressive.

I can see the difference, it's just irrelevant. And tiny, and nothing to fuss over. Nothing like Canon's read noise.

The tonal gradation is lacking b/c ACR only does a 5 EV push. The extra 1 EV push was done using the Shadows/Blacks slider, which is nonlinear and ends up raising blacks while not maintaining tonal relationships - leading to flatter contrast. So you'd just have to spend a little time processing it better, which I didn't care to do for the purposes of this demonstration.

For these types of cameras, software needs to catch up to the hardware improvements.

Also, it's arguably easier to - at ISO 100 - expose for the highlights, then take say 6 shots, then average them to clean up the shadows, then work off of that file. Rather than take 2-3 shots and blend them in HDR software that runs the risk of artifacts, too much HDR look, etc... as jrista was explaining earlier or somewhere else.

Also, both shots I showed could clean up easily.

Really, I don't know what we're arguing or debating any more... :-\

 

[sarangiman]

Impressive? If you CR members can make money off photo's like this congratulations and I admit I'm an idiot and should take up another hobby (maybe lawn bowling/or maybe BINGO) else they are crap.

Hey, you said it buddy, if you think I took that photo for any reason other than a test to prove a point.

 

[sarangiman]

Do you honestly believe you can't push Canon files three stops?

Not without a noise cost. Unless you're talking about ISOs 3200 and above, where now even the lowest signal is amplified to be at or above the noise floor of Canon electronics.

And my initial post about noise after just correcting vignetting - that was a 3 stop push (Canon 5D3 | 24/1.4). So, I believe that answers your question. How much was your push in your example?

I don't follow, either you can lift three stops or you can't, where the highlights are is not in question, ETTR is not in question; were the lifted portions of the image, specifically shadows, lifted three stops and maintained any kind of image quality, that is the question.

Do you believe a Canon sensor, from the current generation, can be lifted three stops and still maintain good quality shadow detail, lack of noise and banding?

No, it's not that simple. It depends on the tone you're pushing. Actually, it depends on the exact signal you're pushing, and where it is in relation to the noise floor. Which is high for Canon.

What's impressive is that is a SIX STOP push. That's the noise levels SIX STOPS deep in the exposure. Imagine what that means for shadows only two or three stops deep. It means they are PHENOMENAL.

What it means, which you can quantitatively show, is that there's (almost) no noise cost in doing that push vs just shooting the correspondingly higher ISO.

And that's an incredibly cool concept. It opens doors.

In another context, it's no wonder people call black-point hacked D800's "CCD-like" in the astro world. The quality of noise in Sarangiman's deep push examples are very much CCD-like in quality...very clean, very random. Run an FFT on a dark frame from that camera, and I bet the resulting image would exhibit nearly perfect Gaussian traits. Personally, I think that's amazing. I've run FFT's on Canon darks...they are nothing close to resembling a perfect Gaussian noise FFT image.

I wonder if that's at least partly b/c Nikon finally decided to add a black offset. A great (albeit not new) idea in my book.

 

[privatebydesign]

I don't follow, either you can lift three stops or you can't, where the highlights are is not in question, ETTR is not in question; were the lifted portions of the image, specifically shadows, lifted three stops and maintained any kind of image quality, that is the question.

Do you believe a Canon sensor, from the current generation, can be lifted three stops and still maintain good quality shadow detail, lack of noise and banding?

No, it's not that simple. It depends on the tone you're pushing. Actually, it depends on the exact signal you're pushing, and where it is in relation to the noise floor. Which is high for Canon.

We are talking about shadows, so sub 10% RGB values in Lightroom, your belief is that you cannot triple those numbers in a Canon file without seeing excessive noise and banding with current generation Canon sensors?

 

[sarangiman]

We are talking about shadows, so sub 10% RGB values in Lightroom, your belief is that you cannot triple those numbers in a Canon file without seeing excessive noise and banding with current generation Canon sensors?

3-stop push is not 'tripling'. It's multiplying by 8. And a 6-stop push is multiplying by 64.

And, yes, since vignetting correction for 24/1.4 is 3 EV, and since I'm - on a number of occasions - noted visible noise/banding from just vignetting correction, yes, I do believe you can't push 3 EV without a noise cost for many lower tones.

My standards are high, though. It's all about the quality of the falloff into the shadows for me. I've seen far too many of my images that show banding right up into the midtones without any exposure pushing at all, let alone a three stop push. To me, I find that 100% completely unacceptable. I've even had that problem with some of my bird photography when shooting at ISO 400 or lower (not all that common, but sometimes the light is ridiculously good.) At the very least, even though it's usually correctable, correcting it affects detail. Reducing the random noise affects detail more. Reducing the color and gaussian components of read noise affects detail even more. It's just one layer on top of another with Canon files. Every layer nuking a little bit of detail. If you really try to clean up the shadows, they just end up mush, and no amount of fiddling seems to bring in that incredible soft tonal falloff that you get with a D800 or D810.

Oh yeah, thanks for reminding me of this. I'd forgotten that I've even seen banding in blue skies in some shots, possibly b/c the other channels were underexposed? Then when I averaged shots to get rid of some of the noise and get a cleaner image, the banding became even more apparent.