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Messages - dtaylor

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256
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 25, 2014, 12:11:58 AM »
Yeah maybe because IR uses NR!!!! of unknown and random amounts while the other measuring company does not.

Because ACR default = "unknown and random amounts...UNKOWN...RANDOM!!!"

Then again, NR doesn't make black steps gray  ::)

257
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 25, 2014, 12:07:57 AM »
Utter lie and fabrication, even your favorite site, flat out says that the 70D feels like it has an old sensor in regards to low ISO performance and that it acts like it's more than 2 stops behind Exmor.

Please post YOUR step wedge shots for evaluation...RAWs...along with lighting details. Thank you.

258
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 25, 2014, 12:05:34 AM »
I am personally convinced that the D800 or D810 could improve my landscape photography. Over the last couple of years, I've seen too many incredible photos on 500px and 1x that demonstrated the incredible power of having two additional stops of DR/Editing Latitude. This one in particular is just mind blowing...I'd LOVE to see anyone try to replicate that with a 5D III. I'd honestly bet good money it's impossible:

What on Earth makes you think that's not an exposure blend / HDR? (It doesn't appear to be GND.) I would also guess the "sunburst" is artificial or enhanced, though I could be wrong on that.

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I've NEVER been able to actually do what this photographer did with a D800.

That's because you can't do it in a single frame unless the sun is heavily masked by something (fog; GND), which doesn't appear to be the case here. Not unless you have a DSLR with a 20+ stop NASA sensor.

259
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 24, 2014, 11:57:00 PM »
The a6000 is much cheaper at $800 (actually $648 now on Amazon).
The a6000 is full metal compared to 70D being plastic.
The a6000 shoots up to 11fps compared to the 7fps on the 70D
The a6000 has a 179 focus points compared to 19 on the 70D

From reviews and comments it simply cannot track like a 70D. What good is 11fps and 179 AF points if the subject doesn't stay in focus as it's moving?

Nice camera no doubt...but mirrorless claims of "world's fastest/best AF" are laughable at this point in time. It never really is that.

260
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 24, 2014, 11:49:37 PM »
It's a simple question. Do you NOT want to have better IQ across the board? Truly? I mean, technology PROGRESSES. So, if you are honestly telling me that you do NOT want better top to bottom sensor IQ....

Every single Canon ILC I have purchased has had better IQ then the camera I purchased before it. The next Canon camera will as well. To say nothing of their lens advancements. As for DR,

Not that I'm hostile to other brands. Canon does not have a FF MILC so I imagine a Sony A7 is in my future.

261
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 24, 2014, 11:46:24 PM »
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(In my experience, "Photographic DR" is far more arbitrary, as everyone seems to define it or calculate it in a different way...

The definition and method of calculation is taught to every single person who earns a degree in photography in the country. A very large number of printers and scientists know it as well. It is not arbitrary.

And yet...it still hasn't been DEFINED. What, exactly, is the calculation you use to determine Photographic DR? Or is the calculation simply: "Shoot a step wedge and judge visually whether you have X stops or Y stops of DR?"

I'm sorry, but a simple visual judgement is insufficient. Your ignoring read noise, which you cannot do. (Well, you can...it just isn't valid...not for electronic sensors.)

Indeed, all measurements in a digital sensor contains noise. The luminance range that is detectable depends on the amount of noise present, discussing DR in digital photography is discussing noise which boils down to statistics. Until dtaylor understand that he would best avoid these discussion and instead go hide under a bridge but he doesn't have that much sense so it is pointless to waste energy on him.

Yeah...probably right.

Pretty smug considering neither one of you have actually tested your theories.

When you do and you see gray patches beyond the 10 stops (or whatever) you predict Canon cameras have because "sensel noise!", come back with a more humble attitude so you can learn.

262
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 24, 2014, 11:39:17 PM »
What, exactly, is the calculation you use to determine Photographic DR? Or is the calculation simply: "Shoot a step wedge and judge visually whether you have X stops or Y stops of DR?"

That's generally good enough, yes, though you're welcome to evaluate the shot with instruments.

There is not a magic formula which allows you to translate engineering SNR for a sensel into photographic dynamic range for an entire digital camera. That seems to be what you are looking for and it does not exist. There are multiple reasons for this, not the least of which is that photographic DR is evaluated for a 2 dimensional light sensitive material with many imaging elements (sensels or grains), and is not based on a single element. If you applied an "engineering" definition of DR, or SNR, to photographic film you would conclude it has 1 stop because at the level of a single grain you would find either silver or clear base and nothing in between. (Ironic that digital cameras are analog at the sensel and film is "digital" at the grain.)

There are other reasons, but the point is looking at sensel SNR...even though it's related...gives a false impression. But just because there is no simple formula to translate sensel SNR into DR does not mean that DR is arbitrary or subjective.

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In every single one of those pages you linked, including the book "The Negative" by Ansel (which I own, BTW), no one actually DEFINES what "Photographic DR" is.

Luminance range between black and white. (For the nth time.)

As for Ken Rockwell: "In photography, dynamic range is the difference between the lightest light and darkest dark which can be seen in a photo." Bingo.

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I do not believe there is a single objective definition of Photographic DR.

Saying this after the references I've provided is...embarrassing. You're arguing to argue, not discussing to learn.

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It's just an arbitrary term, and it seems to be redefined at will.

Every source I linked has the same definition even if they call it by another name (i.e. luminance range). I'm not aware of any other definition in photography.

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I am calling into question the validity of using the old film-based Zone system to describe dynamic range in digital image sensors. Film had no readout system! In film, dynamic range was limited only by the amount of grain, which means it effectively behaved like an "ideal sensor"...the only source of noise was photon shot noise, inherent in the image resolved by the lens itself.

Grain irregularity was itself noise.

I cut a lot from your post where you're theorizing. Observe, then theorize.

263
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 24, 2014, 06:59:09 AM »
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You are correct that some careful NR can close the gap. Thing is, if you actually look at my sample images I recently posted, there is still a gap.

Yes. You might even spot it on a 36" print with the D800 print sitting next to it  ::)

Eh, what?

 ???

Print the full image to 36", both the D800 file and your 5D3 NR processed file. See how many people can spot the difference without it being pointed out to them.

On a 96 ppi monitor you could also just put the two crops side by side and view at 50% in PS. My monitor is calibrated with a Colorvision Spyder that has me set brightness as part of the calibration, and I see very little difference between them. I can still pick out the 5D3 crop, but just barely. If your monitor's brightness is set too high it becomes easier.

But a landscape shot that included shadows pushed and processed like that and shown to people I know? Yeah...no one would notice.

So...honest question...how often do you blow your exposure, push shadows by that many stops, and print 36"?  ;D

Side rant: you may be someone who just needs to get an Exmor camera for whatever you're doing with astro. I don't know. 99% of people who complain about this are complaining because they don't have bragging rights and that's all. Too much pixel peeping and not enough viewing/printing real photos.

264
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 24, 2014, 06:30:14 AM »
I'm debating your definition of DR. You cannot simply shut that down at will.

Yes I can. It is not "my" definition. It is the definition that has been in use since Ansel Adams and Fred Archer developed the Zone System (at least). The first zone above black does not even have any texture or detail, just a tone lighter then black. And it is not dependent on grain/noise.

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Your definition is flat out wrong. Simple as that. :P

http://en.wikipedia.org/wiki/Dynamic_range - Photographers use "dynamic range" for the luminance range of a scene being photographed, or the limits of luminance range that a given digital camera or film can capture, [32] or the opacity range of developed film images, or the reflectance range of images on photographic papers.

Luminance range. NOT detail that has "Sony Exmor" amount of noise or less.

Please also see:

Basic Photographic Materials and Processes, Third Edition - chapters 2 and 5.

http://photo.net/learn/making-photographs/film

http://www.amazon.com/Negative-Ansel-Adams-Photography-Book/dp/0821221868

http://en.wikipedia.org/wiki/Zone_System#Exposure_zones

http://www.luminous-landscape.com/tutorials/zone_system.shtml

http://www.kenrockwell.com/tech/dynamic-range.htm

http://www.stouffer.net/TransPage.htm

http://cameras.about.com/od/technologies/a/What-Is-Dynamic-Range.htm

Shall I go on?

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(In my experience, "Photographic DR" is far more arbitrary, as everyone seems to define it or calculate it in a different way...

The definition and method of calculation is taught to every single person who earns a degree in photography in the country. A very large number of printers and scientists know it as well. It is not arbitrary.

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Not from what I understand about what IR is doing. They are feeding Imatest processed images...images that have had NR applied.

I don't know how many times I have to say it: if you photograph a step wedge and apply NR or scale it down, black squares do not magically become gray. Total DR does not change with NR.

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You compute DR the exact same way for every one of those cameras: 20*log(FWC/RN)/6. That formula results in the following DR for each camera:

1DX: 11.25
5DIII: 10.95
7D: 11.33
70D: 11
D4: 12.72
D800: 13.91
D810: 13.47

Shoot a transmission step wedge with a 70D, 5D3, or 1DX. (7D value actually looks about right.) When you see with your own two eyes that more then 11 stops worth of steps are gray, you will know that your theories are false. Then we can continue and discuss why.

You want T4110 (41 steps in 1/3 stop increments): http://www.stouffer.net/TransPage.htm

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Canon sensors have not changed since before the 7D.

Anyone who has shot a 7D and 70D, or 7D and M, or 5D2 and 5D3 or 1DX, can tell you otherwise. Improvements are small, but that's no different from the evolution of Exmor (i.e. D7000 to latest Nikon bodies).

265
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 24, 2014, 02:24:22 AM »
Well, your just plain wrong about the DR. Your using IR's "total DR" number, which is irrelevant, 

It is the ONLY relevant number. The definition of DR is not up for debate.

How hard you can push shadows due to noise (i.e. grain) is LATITUDE.

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Even IR's results where they don't completely ignore noise even jive, and IR ALSO gets approximately a two-stop difference between Canon sensors and Exmors.

Guess what would happen if you fed Imatest or DxO the D800 and 5D3+NR file you posted? They would report nearly identical DR. But applying NR to the D800 will not reveal any more detail or bump its score the same, at least not with Imatest. (DxO thinks blacker blacks with no detail still = more DR, so maybe their score would go up. But it would also be useless.)

Picking an arbitrary noise/processing threshold and arguing about it is worthless for this very reason.

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You are correct that some careful NR can close the gap. Thing is, if you actually look at my sample images I recently posted, there is still a gap.

Yes. You might even spot it on a 36" print with the D800 print sitting next to it  ::)

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And, it was extra work to do the NR on the 5D III image.

Usually the "extra work" involves moving sliders in ACR. I generally tailor my NR selections based on the image in front of me any way, regardless of sensor, unless it's base ISO and I won't be pushing shadows at all because they're all solid there.

If you don't want to do any work, then you probably aren't converting a RAW in the first place. For those people there are automatic 3 shot HDR modes.

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The real kicker is the gap is growing.

No it's not. It's about the same today as it was when the D7000 came out against the 7D. Both sensor series have improved over time by small increments.

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I don't think we'll be stuck with 14-bit ADC units for long...technology is moving far too fast for that.

Someone has to be able to fabricate a sensor that can produce useful bits >14 first. If someone does that at Photokina while Canon ships a 70D sensor variant, then Canon has a problem. But even Sony's 12 MP FF sensor isn't doing that yet so I kind of doubt it.

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As others have stated, 4k video recording is starting to become a more common feature among competitors, and the quality of that video is higher than you can get with a Canon.

I'll give you that one. As a stills guy I don't personally care, but Canon needs to start shipping 4k as well as some of the other features of ML.

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I've also been getting more and more into astrophotography equipment...Some of these things are RADICALLY superior to what Canon has to offer.

But these are also niche tools, are they not? In terms of general purpose cameras, I'll grant that a Sony Exmor is a better choice for astro, but it's not like you can't do good astro with a 5D2/3 or 6D. Flickr is full of those shots.

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That is TWENTY FREAKIN STOPS!! The thing has a 20-bit readout mode to fully support that many stops as well.

But we don't see that in any general purpose, high resolution ILC gear. So what's the trade off? If it doesn't arrive in our cameras for two years, and Canon does the same thing at the same time or shortly after Sony (for example), then they're not way behind. They would be way behind if Sony's current FF sensors had 20 stops.

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So, the 70D? It doesn't sell because of it's sensor.

The 70D has an excellent sensor that is competitive now. If Sony brings out a 20 stop ISO 25,600 APS-C monster tomorrow, that will change. But you're reading about all this new stuff that no one has yet in a general purpose ILC line. Which means there is a trade off...maybe as simple as fab yields...that everyone is experiencing.

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What happens when Sony drops a LITERAL 16-stop sensor on the market?

Canon will respond. Even if it means buying the sensor from Sony, if their market is threatened they will respond. But my guess is that 16-stop sensor is not coming as soon as you imagine, nor is Canon's that far behind. Plus, I see a lot of patents coming from Canon for RGB multilayer sensors. Foveon shot themselves in the foot by overstating the advantage, but the advantage is significant. Anyone else doing any R&D here?

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To get control of their noise problems, they are going to have to stop manufacturing ADCs they way they have been manufacturing ADCs for over a decade now...

When it affects their market share I'm sure they will. They're still #1, and the smart company pockets profits but has tech ready to go when they need it. I know that sucks when you want to see rapid innovation, but it's typical behavior. If you're the underdog you innovate wildly...and often lose money...trying to get at the top dog. If you're the top dog, you protect your position.

266
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 23, 2014, 10:03:32 PM »
y.

High ISO? In the DPReview and IR studio comparisons the 70D looks pretty much the same as the D7100 (for example). I would shoot either to 6400 if need be.


I  put the camera away at ISO 1250. And I own it.

I guess you would be putting any APS-C away then. Makes sense if you want 24-36" prints. Not so much if you're posting online or printing to 8x10.

The 7D could make a nice ISO 3200 8x10, with noise that looked like tight film grain from a low speed portrait film, as long as you nailed exposure.

267
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 23, 2014, 06:52:34 PM »
I'm still bummed that Canon has STILL not demonstrated they are getting competitive again on the sensor front...re-purposing the 70D sensor in the 7D II just smells really sloppy and cheap....

The 70D sensor is competitive. So what would you like them to do?

Resolution? Better be north of 40 MP to see a real difference, and that's only for those of us who regularly make large prints of finely detailed subject matter (i.e. landscapes shot from a tripod at optimum apertures). Not even Sony can pull that off in APS-C right now and retain high ISO/DR.

Total DR? The 70D is 1/3 stop behind Exmor.

Shadow latitude (noise)? You yourself showed how ridiculously small the difference is when NR is intelligently applied. When I first saw a Canon v Exmor pushed shadow test I thought the tester was purposely lying because I had never seen noise that bad...because I never turn off default NR when pushing shadows hard. In fact I apply more! I routinely push shadows 2-3 stops even with the old, noisy, 7D sensor. The thing I run into pushing shadows is not noise, but a tonality/fine detail/microcontrast wall, and you hit the same wall on Sony.

High ISO? In the DPReview and IR studio comparisons the 70D looks pretty much the same as the D7100 (for example). I would shoot either to 6400 if need be.

Color? Canon seems to have nailed that one. Other people complain and profile their sensors to try and match Canon color.

The next major jumps are going to involve 16-bit designs, multilayer sensors, or some other technology twist. We are well into diminishing returns given the state of sensor fabrication right now.

The only thing "wrong" with Canon's sensors is they score poorly over at DxO relative to Exmor. So do Hasselblad medium format sensors! Only Hasselblad fans are sophisticated enough to know DxO is a joke. I doubt any of their users are silly enough to jump on a forum and say "If Hasselblad doesn't do something about these sensors I'm buying a D810!"

I hope Canon makes a major jump in the 7D2 sensor by applying NR in camera even to RAWs and therefore gaming DxO to get a higher score  ;D

268
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 23, 2014, 07:51:37 AM »
The IR method has a lot more variables and they don't test RAW they test after conversion RAW with cooked in NR of various who knows what degrees

NR does not affect total DR. And they use ACR with default settings for ALL cameras.

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(and that also explains how they manage to get this type of DR to actually measure higher than engineering DR measurements of the RAW file).

If DxO was measuring what you think they are measuring then this would be impossible no matter what processing was performed.

Go take a long, hard look at jrista's processing of the infamous 5D3 vs. D800 online test. DxO claims that there is a 2.5 stop DR difference between these two cameras. If that were the case then that door and those tiles in the far back should be BLACK. No detail or image at all in those regions, just blocked up shadow.

Instead we see the same features that we see on the D800, just with a lot more color noise.

The color noise impacts our ability to push the shadows, or shadow latitude. But the DR is darn near the same. It certainly is not 2.5 stops less.

There is your direct, observational evidence that DxO is wrong.

Perhaps more importantly for someone buying a camera, the final result with NR shows just how small the difference ends up being in the real world. Yes, the D800 is better. Could you spot it on a 36" print? Probably, but it certainly would not ruin the print. 24"? Most people could not without being told to look for it up close. 12"? Nope.

How often do you shoot a scene intended for 36" prints yet blow the exposure so badly that you need to push shadows this hard?   :o

269
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 23, 2014, 07:25:46 AM »
Actually I found out how. IR is measuring after raw conversion and NR has been applied!

NR does not affect how many steps of gray appear between black and white on a step wedge or total DR. It WOULD affect tests against arbitrary noise thresholds for "quality DR."

BTW: they use default settings for ALL cameras.

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Yeah and DxO is more direct,

Black box formulas are not "direct."

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And ironically enough it turns out that the DxO measurement didn't fail and that there is an explanation for the IR result,

Try photographing a step wedge some time. Keep increasing NR until more black squares turn gray  ::)

270
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 23, 2014, 07:10:47 AM »
Well, here's what the IR says about dynamic range.

I like that they use(d) Imatest and a step wedge. That yields an accurate, tamper resistant view of total DR. But I don't care what their opinion is on the definition of DR. The definition was solved before Ansel Adams!

Latitude...which is what you are actually talking about...is important to. But if it's as important to you as people pretend it is in online forums, then you are not exposing correctly, and quality will suffer even with Exmor. Exmor > Canon, but dealing with the scene (GND filter; HDR) will blow both away.

In practice if you are digging deeper then about 2...2.5 stops into shadows for detail then you are sacrificing tonality and micro contrast with any sensor. Canon can handle that about as well as Exmor just using the NR sliders in ACR.

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