October 23, 2014, 05:05:21 AM

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Messages - Lee Jay

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31
EOS Bodies / Re: Multilayer Sensors are Coming From Canon [CR2]
« on: October 15, 2014, 09:36:26 PM »
I've been curious for some time why Lightroom doesn't make extensive use of the capabilities of my video cards...if games can render vastly more complex scenes 60 to 120 times per second using a GPU, Lightroom should be able to do what it does on a 5-layer RAW quicker than it renders a bayer RAW now.

Agreed.  DxO Optics Pro used to be rather slow at displaying images at 100% on my Mac, and even filmstrip thumbnails weren't very fast.  A version back (IIRC), they added GPU acceleration and it sped the rendering up significantly.

The guy that writes the Camera Raw code says GPU acceleration would help very little with the Camera Raw pipeline.


I honestly have a very hard time believing that. There is no way the current code is as parallel as it could be when run on a GPU. CPU's simply cannot achieve that kind of parallelism. I wouldn't be surprised if they had to completely rewrite the ACR pipeline to properly take advantage of GPU power, but I think they should do that anyway, and build in support for pipeline-level plugins so third parties could add things people have been asking for since v2 was released...like debanding support, or AF point overlays, etc.

So, you know more than the guy that's writing the code?  Kind of arrogant, don't you think?


I write heavily parallelized and highly threaded code for a living. I have been for nearly two decades. I think I have the background knowledge to know.


Will you guys knock it off with this crap? I've had enough.

The CR Pipeline is not very parallelizable, according to the guy that writes it.

32
EOS Bodies / Re: Multilayer Sensors are Coming From Canon [CR2]
« on: October 15, 2014, 09:20:41 PM »
I've been curious for some time why Lightroom doesn't make extensive use of the capabilities of my video cards...if games can render vastly more complex scenes 60 to 120 times per second using a GPU, Lightroom should be able to do what it does on a 5-layer RAW quicker than it renders a bayer RAW now.

Agreed.  DxO Optics Pro used to be rather slow at displaying images at 100% on my Mac, and even filmstrip thumbnails weren't very fast.  A version back (IIRC), they added GPU acceleration and it sped the rendering up significantly.

The guy that writes the Camera Raw code says GPU acceleration would help very little with the Camera Raw pipeline.


I honestly have a very hard time believing that. There is no way the current code is as parallel as it could be when run on a GPU. CPU's simply cannot achieve that kind of parallelism. I wouldn't be surprised if they had to completely rewrite the ACR pipeline to properly take advantage of GPU power, but I think they should do that anyway, and build in support for pipeline-level plugins so third parties could add things people have been asking for since v2 was released...like debanding support, or AF point overlays, etc.

For creating a RAW file in the camera, it is doubtful that GPUs would accelerate the process. Creating the RAW file is a read/dump process with very little (if any) processing being done. It is basicly read from the sensor as fast as you can and dump to the buffer....

Creating a Jpg out of the RAW file is a completely different story... Processing that RAW file is a massively parallel operation... the image is typically broken up into 8x8 blocks and run through the jpg compression engine... then groups of blocks are run through the compression engine... and so on until the whole image is done. The 18Mpixel sensor makes an 5184x3456 image... and that makes 279,936 blocks to compress on the first pass, 4374 blocks on the second pass, and 68 blocks to finish off on the third pass..... Since it is essentially the same sequence of operations on each block, parallel cores on a GPU can speed things up by well over a magnitude....

Same thing holds true for rendering images in software to display on the screen or to create print files...

The CR Pipeline doesn't create 8x8 blocks of compressed data.  It creates uncompressed raster data that's highly interdependent (think about applying gradient filters, healing spot corrections, brushed adjustments, etc.).

33
EOS Bodies / Re: Multilayer Sensors are Coming From Canon [CR2]
« on: October 15, 2014, 08:32:23 PM »
I've been curious for some time why Lightroom doesn't make extensive use of the capabilities of my video cards...if games can render vastly more complex scenes 60 to 120 times per second using a GPU, Lightroom should be able to do what it does on a 5-layer RAW quicker than it renders a bayer RAW now.

Agreed.  DxO Optics Pro used to be rather slow at displaying images at 100% on my Mac, and even filmstrip thumbnails weren't very fast.  A version back (IIRC), they added GPU acceleration and it sped the rendering up significantly.

The guy that writes the Camera Raw code says GPU acceleration would help very little with the Camera Raw pipeline.


I honestly have a very hard time believing that. There is no way the current code is as parallel as it could be when run on a GPU. CPU's simply cannot achieve that kind of parallelism. I wouldn't be surprised if they had to completely rewrite the ACR pipeline to properly take advantage of GPU power, but I think they should do that anyway, and build in support for pipeline-level plugins so third parties could add things people have been asking for since v2 was released...like debanding support, or AF point overlays, etc.

So, you know more than the guy that's writing the code?  Kind of arrogant, don't you think?

34
EOS Bodies / Re: Multilayer Sensors are Coming From Canon [CR2]
« on: October 15, 2014, 07:42:47 PM »
I've been curious for some time why Lightroom doesn't make extensive use of the capabilities of my video cards...if games can render vastly more complex scenes 60 to 120 times per second using a GPU, Lightroom should be able to do what it does on a 5-layer RAW quicker than it renders a bayer RAW now.

Agreed.  DxO Optics Pro used to be rather slow at displaying images at 100% on my Mac, and even filmstrip thumbnails weren't very fast.  A version back (IIRC), they added GPU acceleration and it sped the rendering up significantly.

The guy that writes the Camera Raw code says GPU acceleration would help very little with the Camera Raw pipeline.

35
EOS Bodies / Re: Patent: Variable Diffusion Focusing Screen
« on: October 15, 2014, 05:16:21 PM »
And forgive my ignorance but why aren't modern DSLRs fitted with split prism focusing screens.  I shot with a Canon AE-1 and/or A-1 for 20 years and never, ever missed focus on anything.  I was 50/50 in focus with the 5DII and 70-200 2.8 Mk I.  Now with the 5DIII and 70-200 MkII I'm about 90% in focus but still...

As I understand it, there are two reasons - most people use AF and so it's not really needed, and second because the split prism can affect the exposure sensor's reliability in getting the exposure correct.

36
EOS Bodies / Re: Patent: Variable Diffusion Focusing Screen
« on: October 15, 2014, 09:47:13 AM »
I don't care how much diffusion the focusing screen provides, I don't think manual focus is reliable without a split prism.

37
EOS Bodies / Re: EOS 6D Mark II to Move Upmarket? [CR1]
« on: October 14, 2014, 11:11:45 PM »
Until a paid photographer has the tools to post pictures straight to a customer's Facebook from the back of the camera, manufacturers are failing their customers.

I wouldn't do that even if I had a tool that could do it.  It's like saying a chef is a failure because they spent hours preparing a meal when they could have just served the guests some McNuggets in a few minutes.

38
EOS Bodies / Re: EOS 6D Mark II to Move Upmarket? [CR1]
« on: October 14, 2014, 05:38:42 PM »
I wrote some weeks ago, that this could come true.
Friends in Japan see the 6D successor priced around 2000-2200€ and the 5DIII successor around 3500-4000€. The lower prices are the most named one, but the higher ones are rumored too...
Latest rumores for 6DII: Better AF system, more AF points, faster (1-2 fps), 1 double cross sensor, but no AF at f8.
MP count is just incremental increasing 20->22, 22-> 24(25) MP.  No mention about stunning low light capability. 6DII with better video quality.

All rumors are still rumors, as my friends saw the 7DII with a 24MP sensor. But Canon decided to use the 20MP, not the other tested 24MP.

Any idea when?

39
EOS Bodies / Re: EOS 6D Mark II to Move Upmarket? [CR1]
« on: October 14, 2014, 04:15:50 PM »

Trends and fashions change. It is very possible that after a few years of playing with small mirrorless cameras, Asian customers, especially in China where the economy and middle-class is still growing, will trade in their little mirrorless toys for "big boy and girl" DSLRs. Like customers in Europe and the Americas, they may find that if they want to shoot sports, wildlife and birds it's a lot easier to do that with a DSLR.

How many people want to shoot "sports, wildlife and birds." I don't and none of my friends do. YMMV.

The world is changing, and fewer and fewer people are impressed with the size of your lens.

I many people want to shoot landscapes and architecture?  I don't and none of my friends do.

40
EOS Bodies / Re: EOS 6D Mark II to Move Upmarket? [CR1]
« on: October 14, 2014, 01:40:13 PM »
This real world review of the D750 shows what the spiritual successor to the 5D3 (whatever they name it) needs to target. http://petapixel.com/2014/10/14/nikon-d750-review-nikon-youve-created-monster/

PS I'm not interested in a flamewar. Just adding a data point for what the competition's refreshed body is offering.

To me, a 5DIV should be 6552x4368 (28.8MP - the short edge is the same pixel dimension as the 5D classic's long edge) dual-pixel with greatly reduced read and fixed pattern noise compared to the 5DIII.  It should be 7fps (28.8*7 ~= 20.2*10 so the same pixel throughput as 7DII), and have a similar AF system as 7DII.  Personally, I'd like the popup flash (the Nikon D750 and D810 have it so no whining from the "it would make the hump to big" or "it would be too fragile" crowd).  Same video features as 7DII except include UHD as a 1:1 pixel (1.7x crop) option.  This avoids any need to pixel bin or resample and so shouldn't be too difficult to implement (so, no whining from the Canon engineering crowd).  While we're at it, add that same option to the 7DII through firmware (1.425x crop on that camera).  I'd tolerate 24fps which would leave the pixel throughput the same as the stills burst rate, but 30fps would be better).  It should also have the nifty 7DII features such as the strobe thing, the flexible viewfinder thing, and the focus mode lever thing.

Price it around $3k and it'll be a winner for sure.

41
EOS Bodies / Re: EOS 6D Mark II to Move Upmarket? [CR1]
« on: October 14, 2014, 10:14:12 AM »
...Canon seems to be marketing the EOS 7D Mark II on par with the 6D as far as image quality goes...

Where does it say anything about image quality on the chart?  The 6D is obviously NOT marketed to be the same image quality as the 7DII or they'd have the same ISO range, which they don't.

The 6D has much better image quality than the 7DII when both can frame the same.  The 7DII has far superior focusing performance in both stills and video, and a better body.  Pick your poison.

42
EOS Bodies / Re: EOS 6D Mark II to Move Upmarket? [CR1]
« on: October 14, 2014, 10:11:38 AM »
Just come out with them already.  I'd love to see both the 6D and 5DIII replacements announced by spring and available by summer.

43
EOS Bodies / Re: EOS 6D Mark II to Move Upmarket? [CR1]
« on: October 14, 2014, 09:40:47 AM »
If the 6D is a full-frame 60D, making the 6DII a full-frame 70D doesn't seem unreasonable, and that would be a pretty significant improvement.  The 5DIV should then be a full-frame 7D2.

44
EOS Bodies - For Stills / Re: How to differentiate crop vs. FF
« on: October 13, 2014, 11:47:07 AM »
It's still mainly overall cost.  You're correct that using the same lens for a distant subject, more VF magnification and more AF points on subject are an advantage.  But unless you're already at 1200mm (600 II + 2xIII), you're still talking cost savings.  600/4 on FF will beat 400/5.6 on APS-C.

It's more complex if you need a zoom lens.  A 100-400 will be better (for resolving power) on a 7D than on a 5D, and a longer option is either crazy expensive and narrow in range (200-400/4) or just becoming available from third parties (150-600s).
Quote

On the other hand, if someone prefers wider DOF...will find more advantages in APS-C.
There's an exception, in that if your lens is stopped down to its narrowest aperture, APS-C gives deeper DoF because you can't stop the lens down further.  But by then, diffraction will be softening the images a fair bit, and that will be worse on APS-C at typical pixel densities, so in that case you're trading sharpness for DoF.

Because of that diffraction, there is another option - a wider framing.  Moving back or zooming out will get you DOF without costing you resolving power because diffraction has eaten it all anyway.

45
EOS Bodies - For Stills / Re: How to differentiate crop vs. FF
« on: October 13, 2014, 10:56:02 AM »
There's one big advantage of full-frame that a lot of people don't recognize - the variety of zoom lenses starting at 24mm.

Full frame:
24-105/4L IS
24-70/4L IS
24-70/2.8 II
Tamron 24-70/2.8 VC
Sigma 24-70/2.8
Sigma 24-105/4 OS

Crop:
15-85/3.5-5.6 IS


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