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Messages - dtaylor

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Canon General / Re: A Rundown of EOS 7D Mark II Information
« on: August 18, 2014, 04:56:54 AM »
And I dislike it when people post stuff like this without actually reading and understanding what they respond to.

You made the same wrong claim and prediction that you've made before. You will not see another step in the higher MP image. I know because I've tried these things. I wish you would to.

Canon General / Re: A Rundown of EOS 7D Mark II Information
« on: August 18, 2014, 04:24:25 AM »
Actually I can't find a generic definition for DR, different fields, different definitions. However the ones I have seen for photography are engineering DR and Bill Claff's photographic DR which is something else than dtaylor's photographic DR.

I hate when people push a theory without having first observed the very things the theory attempts to explain. It seems to be a core part of human nature and is rampant from silly forum debates all the way to the leaders of nations.

Order a Stouffer transmission step wedge. Shoot it with different MP sensors at the same tech level (Sony A7 and A7R; Nikon D600 and D800; etc). Scale. Observe.

You will not see what your theory predicts you will see.

Canon General / Re: A Rundown of EOS 7D Mark II Information
« on: August 18, 2014, 04:10:46 AM »
All i care about is images ... And i know, i cannot get such images with the 7D or the EOS-M and also not with a Canon 6D or 5D3 or 1D-X.

Changing this post because I shouldn't hand wave the claim.

Let's take his first shot of the model in the chair with "Exceptional dynamic range, from the bright window to the deep shadows with no noise and smooth tonal trasition. No fill was added to this severely back lit shot."

* The window is blown completely out.
* The shadow to the right is lost completely to black.
* Critical point: a strand of hair on the model's head is also blown out. She wasn't as underexposed as you might imagine.

Please note that these are technical observations. The shot itself is very nice. Sometimes you want clipped highlights or shadows for contrast with the subject. He is making very good use of bright, blown out backgrounds for "glow" and contrast.

But this shot does not have "exceptional dynamic range." I'm sure the model was underexposed in the original file, but I doubt he had to push more then a stop or two, and this would not have been from the deepest shadows. She was closer to middle gray then to black.

If you cannot get a similar image under similar circumstances with one of the Canon cameras listed, the problem is not the camera.

Same thing for the next two samples. The third sample is the most underexposed, but he did not push the shadows very hard as she is not as brightly exposed in the final version. I've pulled more detail then that back from shadows like that with Canon sensors, but you will want to apply some NR when you do so.

You can come up with examples where Exmor yields more DR / better latitude (ability to push shadows around).

These are not it.

Photography Technique / Re: APOLLO missions - image inconsistencies
« on: August 18, 2014, 02:35:03 AM »
Now I'll expand that a little by saying, it certainly does appear that some of the images appear to have been made in a staged production environment, or in near-earth-orbit, or composited in such a way as to try make them appear genuine when they may not be.

Wait a minute...are you saying the house cat was NOT on the moon???  :o

My life will never be the same...

Canon General / Re: A Rundown of EOS 7D Mark II Information
« on: August 17, 2014, 11:46:05 PM »
All we care about it getting a relative difference between sensors in an easy to test, repeatable way. Engineering DR covers that.

No it does not. It's related to it, but it does not directly translate to it.

Sure the exact numbers it claims may not agree with what you find usable which would almost certainly be a lower number, but it would be uniformly lower.

But it's not. The differences between DxO reports on one hand and step wedge tests or Imatest reports on the other are not uniform, and are not even consistently lower. As has been pointed out, Canon scores much higher on the latter tests.

If you just want to know to what degree one camera will differ from another in relative terms nothing wrong with using normalized engineering DR.

It just doesn't tell you anything about photographic DR.

EOS Bodies / Re: Exmor vs DualISO
« on: August 17, 2014, 05:49:10 PM »
First off, to raptor3x - good article and great comparisons!

Doesn't this show in real world terms just how easy, without changing any sensor tech, it would be for Canon to improve one of the most complained about aspects of their current sensor design?

Complained about by who? Geeks arguing on forums? (No offense intended, I am a geek arguing on a forum.)

Even when you do have to push Canon shadows a little hard...shove the color NR slider over, all the way to the right if you have to, and give it some luminance NR. They're still not as good as Exmor shadows. But the difference is much smaller in a large print or stretched across a large monitor, and completely gone at average print and viewing sizes. The difference is never as large as it is while pixel peeping with minimal or no NR.

Just last night I was revisiting a Canon 7D landscape file with pushed shadows, not quite as hard as this test but hard enough. Pixel peeping on screen I can see the noise and it annoys me a bit. Printed to an Epson Ultra Premium Luster 17x22 sheet for one of my portfolio albums? I can't find any of that noise with my nose on the print.

Speaking of landscapes...high end professional landscape work is not produced by pushing Exmor shadows 4-5 stops. Landscape photographers bracket and HDR. Compare a HDR image to a heavily pushed image, even from Exmor, and the difference in tonality and fine detail will jump off the print at you. With AEB you can easily hand hold a 3 frame bracket.

All that said...I do find it puzzling that Canon went through the effort to make this possible in the sensor hardware but then never exploited it in the firmware. Are they afraid that it might be confusing to users, especially with the HTP mode option? Just add an Extended Dynamic Range (EDR) mode for RAW only and clearly state it's for pro users who are going to manipulate the tone curve in RAW.

It's dumb for Canon not to do this. But it is a much smaller issue, with far less impact on their bottom line, then any of us seem to realize.

Canon General / Re: A Rundown of EOS 7D Mark II Information
« on: August 17, 2014, 05:13:25 PM »
First of my examples yes you will same DR, second of example wrong, you will see different DR

Please actually try this experiment some time.

If signal to noise performance per pixel is equal, a higher megapixel sensor will always capture more information.

Spatial information != luminance information.

Canon General / Re: A Rundown of EOS 7D Mark II Information
« on: August 17, 2014, 05:11:20 PM »
But this isn't dynamic range, it's latitude, and these two are confused, especially when comparing Canon vs Sony Exmor. The actual dynamic range is not as dramatically different as the Exmor missionaries like to champion, but the Exmor does have considerably more latitude in the extreme low lights. However most of us never have a need to lift low lights to the extent it becomes a problem with Canon.

So I would say down sampling does have a slight advantage in latitude, but this has nothing to do with dynamic range.

I initially skimmed over this but wanted to come back to it because you nailed it.

Canon General / Re: A Rundown of EOS 7D Mark II Information
« on: August 17, 2014, 04:08:50 PM »
Well now that we've concluded the discussion of a touchscreen – which might be defined as "merely trivial," it appears we can get back to the discussion of dynamic range, which would fall into the category of "manifestly trivial."

But Canon hasn't updated their sensors since 1969 and Sonikon sensors get 9,001 more stops of dynamic range and some say if the 7D mkII sensor isn't revolutionary Canon will die!

Or so I read in a forum on the Internet last Thursday  ;)

Canon General / Re: A Rundown of EOS 7D Mark II Information
« on: August 17, 2014, 04:06:38 PM »
In case someone doesn't get it:

You won't see more steps in a shot of a transmission step wedge by downscaling, the downscaled image will look exactly the same unless you downscale so much that you see pixelization. If  you compare a shot taken with a 8mpix sensor against shot taken with a 36mpix sensor where each pixel has exactly the same DR in both sensors however...

You will see the exact same DR in both shots. No different then if you shot 8x10 Velvia 50 and 35mm Velvia 50 and compared them in terms of DR.

Canon General / Re: A Rundown of EOS 7D Mark II Information
« on: August 17, 2014, 04:03:34 PM »
Not between us I guess since it's 1 vote against 1 vote, but at least DxO and 90% of the info out there agrees with me (it's just you and a handful of others on here and DPR who don't).

Have you even looked at other test sites? DxO is always the odd ball out when it comes to DR tests. Their results are different from Imatest as well as straight up transmission step wedge tests every single time. The latter two are usually in close agreement.

DxO simply has no idea what photographic dynamic range is.

Which would explain why their low ISO quality hasn't improved since 2007. (or more likely the big guys simply didn't want to spend $$$ to make new fabs, which are very expensive it is true)

Both Canon's FF and APS-C sensors have better DR today then they did in 2007. Even their 18 MP sensor has improved with each "minor" change/iteration. I suspected this the first day I processed RAWs from my M. Looked it up and sure enough, about 1.5 stops more DR then the original 18 MP sensor in my 7D.

Canon General / Re: A Rundown of EOS 7D Mark II Information
« on: August 17, 2014, 03:17:46 AM »
But it DOES have bearing on reality. And even if you don't believe and numbers of definitions or whatnot, I mean just look at the images, it tells the tale that they do have a bearing on reality.

I have looked at the images. Then I've openly laughed at DxO's estimates of DR.

One of my pet peeves is when people endlessly theorize where they should be simply observing. Shoot a transmission step wedge in RAW and develop with ACR. Canon sensors will not land in the 10.x stop range, but the 12.x stop range. Sony Exmor will land in the 13.x stop range, not the 14.x range. It doesn't matter what scale you view the step wedge at.

Now if you insist on viewing everything at 100%...

This has nothing to do with photographic dynamic range.

Canon General / Re: A Rundown of EOS 7D Mark II Information
« on: August 17, 2014, 02:23:07 AM »
The way DR is measured here you simple compare max signal to the noise floor and the max here is just the perfect white, channel 100% blown, max well value.

And this is not photographic dynamic range.

OTOH, though, the one and only definition of DR in signal processing...

...is not the same as the one and only definition of DR in photography.  ;)

Appreciate your post, you get why there's confusion, just trying to illustrate for those who insist DxO DR measurements have any bearing on reality.

Canon General / Re: A Rundown of EOS 7D Mark II Information
« on: August 17, 2014, 01:05:43 AM »
You'd make a great politician

Seriously, there's no call for such grevious insults!   :o

Wow...a politician...that's worse then insulting someone's mother!  :o

Canon General / Re: A Rundown of EOS 7D Mark II Information
« on: August 17, 2014, 01:03:25 AM »
Your problem is trying to compare high frequency noise to noise of lower frequency as if they were the same thing.

I'm not comparing noise at all. Clipped shadows and highlights do not magically reveal detail because the noise level went down. There is no detail to reveal at that point.

DxO's definition of dynamic range is the definition some guy looking at an oscilloscope might come up with if he had never touched a camera. It is not photographic dynamic range.

Well his files show

Where can they be downloaded?

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