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Messages - dtaylor

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212
Lenses / Re: 50 mm Can't make up my mind!
« on: October 25, 2012, 05:32:01 PM »
Sigma 50 1.4 any day of the week. Wide open it's comparable to the Canon 50 1.2L.

213
EOS Bodies - For Stills / Re: 1Dx simple DR stress test
« on: October 19, 2012, 07:34:58 PM »
The old sensor tech in Canon  is not up to date 2012 and  in a comparison with Sony, not much to discuss

Oh boy! A 7D now has more DR then a 5D3. LOL! Take that FF fans!  ;D

And the D800 has 100% perfectly efficient ADCs. I didn't think that was physically possible.

Funny that Imaging Resource was able to get 12.5 stops from the 5D3  ::)

214
EOS Bodies - For Stills / Re: 1Dx simple DR stress test
« on: October 19, 2012, 06:38:58 PM »
Here we go

I'm sorry...do you think that's a good example of DR? Try lifting those shadows in PS by 100%. See the noise? See the banding? Yuck!

You should have photographed that dead horse with an Exmor sensor, underexposed by 3 stops so we could all see how great Sony sensors are.

Pathetic man...really just pathetic  ;D

215
EOS Bodies / Re: do crop sensors really add reach?
« on: October 19, 2012, 06:34:00 PM »
Some are reporting equivalent IQ when the 5D2 image is cropped to match the 7D FOV.

At low to mid ISO...nonsense. They're probably sharpening the files the same or not sharpening at all, and basing their judgement on that mistake. And/or getting hung up on photon shot noise that disappears with a light NR pass.

That said...the difference is small to nonexistent unless you both crop further and print large. I've got 20" surfing prints made from 8-10 MP crops out of 7D files. Never would have made it that large with a 5D2, 5D3, or 1Dx (given the same lens). Anyone who questions that the 7D provides extra reach can go ahead and try to make 20" prints from 2-3 MP FF crops. The difference in IQ will be quite obvious.

But...I've only rarely had to both crop further and print large. If you're just trying to match APS-C's reach...not any further...then the differences just won't matter, especially when printing 8x10, 11x14. But even at 20" you can get away with it. Wildlife and sports do not stress resolution like a landscape. It might sound hard to believe, but 8 vs. 18 MP isn't that big of a deal in a 20" print of a surfer or deer, given proper post processing.

So yes, crop sensors really do add reach. But the differences are only apparent under extreme circumstances.

216
EOS Bodies - For Stills / Re: 1Dx simple DR stress test
« on: October 19, 2012, 06:22:43 PM »
so you people do not think it is a wise way for Canon to either buy Sony sensors  fast as he...  or show that they can do anything similar as Sony, Panasonic, Omnivision, Aptina???????????????????

I think I'm going to buy a 5D3 just to annoy you  ;D

217
EOS Bodies - For Stills / Re: 1Dx simple DR stress test
« on: October 19, 2012, 06:20:54 PM »
what a baloney, has a little more DR  seeking recognition and approval , I have shown with pictures and measurable data that Canon's sensors are  a lot  inferior compared to  Sony, 2 stops DR and banding and pattern noise, get a life

You've spent how much time beating the DR horse on this forum?  :o

And you're telling other people to get a life?  ::)

218
EOS Bodies - For Stills / Re: 1Dx simple DR stress test
« on: October 19, 2012, 06:19:36 PM »
Where is Nikon's MP-E 65mm?  Where is Nikon's 600mm f/4 lens which is light enough that I can carry it for a 5 km hike then use it to take a handheld shot?

Oh snap!  ;D

But...but...but...DYNAMIC! RANGE!  ::)

In all seriousness, great shots Neuro. The macro shot is awesome.

219
EOS Bodies - For Stills / Re: 1Dx simple DR stress test
« on: October 19, 2012, 06:17:45 PM »
Tis is 1dx vs nikon d800 in the shadow same exposure time same f-stop, d800 to the right

No NR, which we can see from the original post makes a huge difference and minimizes (though not eliminates) the difference.

But why compare "best possible" when we're out to make a point!

220
EOS Bodies - For Stills / Re: Full Frame Sharper Than Crop?
« on: October 19, 2012, 06:10:18 PM »
You have to remember that lens resolution is not a single number. It's an MTF curve describing detail contrast for a given resolution. The higher the resolution, the lower the detail contrast. For a given number of megapixels, crop sensors use smaller pixels. That means detail is recorded at a lower point on the lens MTF curve...lower contrast...vs. a FF sensor.

So yes, FF DSLRs provide sharper images out of camera.

However, at low to mid ISO this is a non issue. All DSLR images (or at least all DSLR images with AA filters) benefit from sharpening, and most benefit from local contrast enhancement. You're going to sharpen the files either way. With crop you just sharpen more in your RAW converter or PS. If you want out of camera JPEGs, you turn up the camera sharpening a little more.

At high ISO this works against crop bodies because the sharpening enhances the noise. And it's at high ISO that I think FF really distinguishes itself. But for all the talk about FF vs. crop, at low to mid ISO there really isn't much difference. Nothing that would stand out even in a 24" print. (Even 4/3rds is capable of matching crop/FF with the same MP count at low ISO.)

Diffraction softens the image. At f/22 (FF) and f/16 (crop) the impact is enough that you cannot fully compensate with sharpening in post. I do not use f/22 on FF, and do not use f/16 on crop, except in very special circumstances. With landscape shots I try to use hyperfocal focusing and the largest aperture possible while still retaining the DoF I want. LiveView is great for evaluating this.

Note that diffraction does not impact any format more than any other for a given FoV and DoF.

221
EOS Bodies / Re: DxOMark Sensor Performance: Nikon vs. Canon
« on: October 17, 2012, 06:21:06 PM »
I find it interesting that many would like to make it sound like an "underexposure" is the end of the world, and a photographical failure.

For the record: I believe that a "correct" exposure is the exposure that maximizes the qualities you desire for the scene. If you wish to capture the maximum possible dynamic range, your exposure may be over/under to take advantage of your particular sensor/film.

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Now try to understand the implications the sentence in bold above sets. Getting an exposure "right" is NOT the same as trying to make 14-16% gray as you see the image conform to a certain photometric exposure at the film surface!

Agreed 100%.

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Film has more latitude, but much less usable DR within a fixed scene

DR and latitude are simply two ways of looking at the same thing. They are not separate characteristics.

Latitude, or room for exposure "error", is basically sensor or film DR - scene DR.

The rest of your observations are spot on.

222
EOS Bodies / Re: DxOMark Sensor Performance: Nikon vs. Canon
« on: October 17, 2012, 06:15:14 PM »
This is taken 15 min ago and shows the difference in shadows, low levels 5dmk2 and d800. I  have lifted the motive exactly the same.

RAW files please.

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And regarding  to ISO and   "holding iso" Canon 1dx is exposed richer in tests like  Imaging Resource, this means that 6400iso is more like if 1dx has been exposed after 4000Iso compared to Nikon D4 and therefore it is not a valid test

Stop. You have already been told this is not the test scene they use to compute DR, noise, etc. Don't make this mistake again!

223
EOS Bodies / Re: DxOMark Sensor Performance: Nikon vs. Canon
« on: October 17, 2012, 06:11:58 PM »
Their dynamic range is their dynamic range. Period. You can reduce it. You can shift tones around, lifting shadows and such. But you can't extend it.

Is that the assertion? Or is the assertion that a 36 MP sensor with 13.2 bits of DR at 36 MP should be described as having 36 MP of resolution and 13.2 bits of DR?

Camera 1 has 36 megapixels and 11 stops of dynamic range per pixel, camera 2 has 20megapixels and 12 stops of dynamic range per pixel.

Which camera has more dynamic range if I display or print their images at the same size ? If I downsample the 36mpx image to 20mpx, I will get more than 11 stops of dynamic range, but do i get more than 12 ?

I think this is a pretty valid question, provided you intend to view the whole image on print or screen, as opposed to just viewing 100% crops.

224
EOS Bodies / Re: DxOMark Sensor Performance: Nikon vs. Canon
« on: October 17, 2012, 06:09:29 PM »
Well, if I have a noisy image (ie with poor DR), it will be usable only at smaller print sizes than a less noisy one. That is a real world example of down-sampling, and if what you claim were true the small print would show exactly the same noise and DR than the larger one.

It does show exactly the same DR. You're making a subjective, aesthetic judgement as to acceptable print/view size due to noise. (And it's not down sampling unless you have a really crummy printer.)

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As to the continued assertion that downsampling can not increase bit depth,

No. That's not the argument. (This is like pulling teeth!)

Pay careful attention: down sampling cannot increase *** photographic dynamic range ***

In photography dynamic range is the range of usable detail, not the range between white and black points.

You have a RAW file. It has some noise. Black is not black, but a really dark gray because of the noise. You down sample and kill some of the noise. "Aha! My blacks are blacker! My bit depth is greater!" So what? You didn't gain one drop of detail. In fact you threw some of it away!

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BTW, downsampling a 1 bit image is not an artificial example. Early monochrome printing relies on this technique. If you stand up close you see a noisy mess of dots. If you stand further away (making the image smaller - ie downsampling), you start to perceive the image as have graduated tones rather than just patches of plain white or plain black.

Everyone knows this, but it's false analogy.

225
EOS Bodies / Re: DxOMark Sensor Performance: Nikon vs. Canon
« on: October 17, 2012, 05:52:38 PM »
Where is your evidence or explanation?


For real, usable DR tests, look to IR and DPReview. (Unfortunately DPReview no longer posts RAW DR, but their tests are still valid for JPEG.)

The explanation has been posted repeatedly, and was posted again just a second ago.

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I tested the DR myself and got same results and so have others.


You're making the same mistake as the others. Noise inflates the black point. Down sampling reduces noise, lowering the black point. But the black point is not actually the floor of dynamic range. The floor is the point where usable detail ceases to exist. Down sampling actually throws away detail. It cannot extend DR.

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I've seen improvements over that time period. DPReview saw improvements.


On what? 5D3 has actually worse DR than the 1Ds3.


In JPEG the 5D3 is better, as noted by DPReview. Unfortunately they did not post RAW values for the 5D3.

Imaging Resource has Imatest RAW values for both, and the 5D3 is one stop better.

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real world, accounting for banding, I'd say D800 does more than 3 better than 5D3 and even ignoring banding it's more than 2.


"Real world"...that would be a switch. Please post real world shots that prove this. Include a transmission step wedge. Oh yes: downloadable RAW files for analysis are mandatory.

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And not that I want to go here, but you've finally gotten me partially to this point, and sure even the most brilliant are wrong at times, absolutely true, and I'm not saying who here and on the other forums is who, but there are not only engineers but theoretical physics PhDs and other such, including some who are world renowned, posting in some of these threads and on some other threads and.... not on your side on this.


What is this: an appeal to imaginary authorities?  ::)

http://www.nizkor.org/features/fallacies/



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Whether or not the 5D4 has better DR has nothing to do with these stupid threads, and everything to do with their engineers. I have little doubt they are working on it.


Did you know that another division of Canon sent a patent for better DR to the DSLR division and got told to get lost, DR, what?, why? bye. Apparently they didn't even let their engineers look at it! So maybe they do need to be woken up.


Source?


A Canon employee (non-DSLR division) on another forum.


More imaginary friends = no source. Don't repeat the claim without a source.

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