October 26, 2014, 04:05:45 AM

Author Topic: 'Revolutionary' Dual Pixel AF Explained  (Read 12841 times)

Ellen Schmidtee

  • Canon 6D
  • *****
  • Posts: 441
    • View Profile
Re: 'Revolutionary' Dual Pixel AF Explained
« Reply #30 on: July 26, 2013, 05:34:30 PM »
The supported lens box has some very disconcerting information.  I'm wondering about 3rd party lenses that should work but will be in contrast-detect just because they aren't "supported".  Also, what's the point of having this function work at f/11 if it doesn't work with teleconverters?  Who has a "supported" bare f/11 lens?

I assume for continuous focus while shooting video.

canon rumors FORUM

Re: 'Revolutionary' Dual Pixel AF Explained
« Reply #30 on: July 26, 2013, 05:34:30 PM »

Drizzt321

  • 1D X
  • *******
  • Posts: 1674
    • View Profile
    • Aaron Baff Photography
Re: 'Revolutionary' Dual Pixel AF Explained
« Reply #31 on: July 26, 2013, 07:45:58 PM »
So let me get this straight....

What the Dual Pixel AF is doing, is that the sensor is actually a two 20mp sensor that is adjacent to each other in a way that it is detecting parallax from the slightest difference between the two pixels?

If that is the case, isn't it actually easier for macro lenses to focus? Since the closer an object is, the parallax effect is more apparent, giving the sensor more difference to detect.

Not exactly. It's that it has 2 photosensors next to each other, each one taking up 1/2 of the pixel. Think of them more as sub-pixels, however they can be used separate to detect the phase of light that is coming in which can determine if that point on the subject is in focus or not, and if not, what direction the lens needs to be focused towards.

So it's really a 40M photosensor sensor, with 2 photosensors per pixel for 20MP output.
5D mark 2, 5D mark 3, EF 17-40mm f/4L,  EF 24-105mm f/4L IS USM, EF 135mm f/2L, EF 85mm f/1.8
Film Cameras: Mamiya RB67, RB-50, RB-180-C, RB-90-C, RB-50, Perkeo I folder, Mamiya Six Folder (Pre-WWII model)
http://www.aaronbaff.com

samkatz

  • PowerShot G1 X II
  • ***
  • Posts: 56
    • View Profile
Re: 'Revolutionary' Dual Pixel AF Explained
« Reply #32 on: July 26, 2013, 08:36:03 PM »
for live view shooting to become primary, someone needs to come up w/a replacement for the LCD that displays well in bright light.  We've heard about OLED and other techns. etc for years but don't see it yet

Also, built in I.S.. would help Canon help photographers use Live View more. W/o a tripod it's hard to hold camera steady far a way from the body. I.S.helps a little but it's not in the camera.


sagittariansrock

  • 1D X
  • *******
  • Posts: 1448
    • View Profile
Re: 'Revolutionary' Dual Pixel AF Explained
« Reply #33 on: July 27, 2013, 01:55:25 AM »
Am i the only one who prefers shooting with the optical viewfinder, even if live view is tzhe same speed? I think its not long anymore til Canon only releases only mirrorless cameras if the AF speed is the same. And then people like me can pay another 899$ or whatever for an electronic viewfinder :(

There are definite benefits to having an EVF instead of a OVF "if and when" live view attains same speed. Other than the increase in frame rate (when processor and memory pipelines become the only rate limiting step), we will get brighter viewfinders, won't be constrained to the size of the pentaprism for magnification, and get better eye relief. And I am sure EVFs will not be so expensive when they are mass marketed.
EOS 5DIII, EOS 5D | Rokinon 14mm f/2.8, TS-E 17mm f/4L, EF 24-70mm f/2.8L II USM, EF 35mm f/1.4L USM, EF 100mm f/2.8 Macro USM, EF 135mm f/2L USM, EF 70-200 f/2.8L IS II USM, 1.4x III, 2x III | 600-EX-RT x3 | EOS M + EF-M 22mm f/2

carpandean

  • SX60 HS
  • **
  • Posts: 2
    • View Profile
Re: 'Revolutionary' Dual Pixel AF Explained
« Reply #34 on: July 27, 2013, 08:18:39 AM »
And then people like me can pay another 899$ or whatever for an electronic viewfinder :(
And I am sure EVFs will not be so expensive when they are mass marketed.

The most expensive add-on EVF from Olympus, Panasonic, Sony, etc., is the one for the RX1, which is $450.  The top one for the NEX is $350 and for Olympus is under $300.  Each of those companies has released entire camera bodies with built-in EVFs for under $1000, and some under $800.  In general, on a camera already equipped with an LCD for live-view on the back, an EVF isn't much more than a second screen.  As such, if you take a DSLR, remove the mirror-box and replace the OVF with an EVF, it should be less expensive to produce.  That's one reason why you'll see the OVFs replaced on the lower-level DSLRs first.  Consumers at that level won't care (or even know) about the marginal benefits that an OVF has. 

A system like this removes the third biggest hurtle for mirrorless migration.  The top-two are marketing and a well-developed lens selection.  If Canon brings this system to the EOS-M and Nikon refines their on-sensor PDAF, then eventually one or both will put the marketing $$'s behind it, and #1 will go away.  #2 will simply go away with time.  The high-end OVF-based bodies with be around for a long time, but the rest ...




Lee Jay

  • 1D X
  • *******
  • Posts: 1143
    • View Profile
Re: 'Revolutionary' Dual Pixel AF Explained
« Reply #35 on: July 27, 2013, 09:01:18 AM »
Here's a pro grade EVF for you.

http://www.red.com/store/products/red-pro-evf-oled

Even a quality consumer grade EVF is an expensive device compared to an OVF.

Lee Jay

  • 1D X
  • *******
  • Posts: 1143
    • View Profile
Re: 'Revolutionary' Dual Pixel AF Explained
« Reply #36 on: July 27, 2013, 09:04:35 AM »
The supported lens box has some very disconcerting information.  I'm wondering about 3rd party lenses that should work but will be in contrast-detect just because they aren't "supported".  Also, what's the point of having this function work at f/11 if it doesn't work with teleconverters?  Who has a "supported" bare f/11 lens?

I assume for continuous focus while shooting video.

Pffft...I want it so I can use a 2x TC on an f/5.6 lens.

canon rumors FORUM

Re: 'Revolutionary' Dual Pixel AF Explained
« Reply #36 on: July 27, 2013, 09:04:35 AM »

Ellen Schmidtee

  • Canon 6D
  • *****
  • Posts: 441
    • View Profile
Re: 'Revolutionary' Dual Pixel AF Explained
« Reply #37 on: July 27, 2013, 11:27:35 AM »
The supported lens box has some very disconcerting information.  I'm wondering about 3rd party lenses that should work but will be in contrast-detect just because they aren't "supported".  Also, what's the point of having this function work at f/11 if it doesn't work with teleconverters?  Who has a "supported" bare f/11 lens?

I assume for continuous focus while shooting video.

Pffft...I want it so I can use a 2x TC on an f/5.6 lens.

That would be cool. A 400mm f/5.6 + 2.0x TC combo is ~15% the price of the 800mm f/5.6.

jrista

  • Canon EF 400mm f/2.8L IS II
  • *******
  • Posts: 4484
  • EOL
    • View Profile
    • Nature Photography
Re: 'Revolutionary' Dual Pixel AF Explained
« Reply #38 on: July 27, 2013, 11:50:06 AM »
The supported lens box has some very disconcerting information.  I'm wondering about 3rd party lenses that should work but will be in contrast-detect just because they aren't "supported".  Also, what's the point of having this function work at f/11 if it doesn't work with teleconverters?  Who has a "supported" bare f/11 lens?

I assume for continuous focus while shooting video.

Pffft...I want it so I can use a 2x TC on an f/5.6 lens.

That would be cool. A 400mm f/5.6 + 2.0x TC combo is ~15% the price of the 800mm f/5.6.

And...might produce 15% the quality? ;P

Ellen Schmidtee

  • Canon 6D
  • *****
  • Posts: 441
    • View Profile
Re: 'Revolutionary' Dual Pixel AF Explained
« Reply #39 on: July 27, 2013, 12:05:01 PM »
The supported lens box has some very disconcerting information.  I'm wondering about 3rd party lenses that should work but will be in contrast-detect just because they aren't "supported".  Also, what's the point of having this function work at f/11 if it doesn't work with teleconverters?  Who has a "supported" bare f/11 lens?

I assume for continuous focus while shooting video.

Pffft...I want it so I can use a 2x TC on an f/5.6 lens.

That would be cool. A 400mm f/5.6 + 2.0x TC combo is ~15% the price of the 800mm f/5.6.

And...might produce 15% the quality? ;P

1. Yes, you do get what you pay for.

2. There are lot more people who could buy the combo than there are people who could buy the 800mm f/5.6.

3. Maybe the 400mm f/5.6 would get a mk2 upgrade, etc.

Lee Jay

  • 1D X
  • *******
  • Posts: 1143
    • View Profile
Re: 'Revolutionary' Dual Pixel AF Explained
« Reply #40 on: July 27, 2013, 10:33:56 PM »
The supported lens box has some very disconcerting information.  I'm wondering about 3rd party lenses that should work but will be in contrast-detect just because they aren't "supported".  Also, what's the point of having this function work at f/11 if it doesn't work with teleconverters?  Who has a "supported" bare f/11 lens?

I assume for continuous focus while shooting video.

Pffft...I want it so I can use a 2x TC on an f/5.6 lens.

That would be cool. A 400mm f/5.6 + 2.0x TC combo is ~15% the price of the 800mm f/5.6.

And...might produce 15% the quality? ;P

The 400/5.6 is optically superior to the ancient and badly out-of-date 100-400L, and I got this from the 100-400L + 2x TC.  Fortunately, the moon doesn't move too fast for the T2i's contrast-detect focusing.

http://photos.imageevent.com/sipphoto/samplepictures/T2i__3574%20edited.jpg

jrista

  • Canon EF 400mm f/2.8L IS II
  • *******
  • Posts: 4484
  • EOL
    • View Profile
    • Nature Photography
Re: 'Revolutionary' Dual Pixel AF Explained
« Reply #41 on: July 27, 2013, 11:56:56 PM »
The supported lens box has some very disconcerting information.  I'm wondering about 3rd party lenses that should work but will be in contrast-detect just because they aren't "supported".  Also, what's the point of having this function work at f/11 if it doesn't work with teleconverters?  Who has a "supported" bare f/11 lens?

I assume for continuous focus while shooting video.

Pffft...I want it so I can use a 2x TC on an f/5.6 lens.

That would be cool. A 400mm f/5.6 + 2.0x TC combo is ~15% the price of the 800mm f/5.6.

And...might produce 15% the quality? ;P

The 400/5.6 is optically superior to the ancient and badly out-of-date 100-400L, and I got this from the 100-400L + 2x TC.  Fortunately, the moon doesn't move too fast for the T2i's contrast-detect focusing.

http://photos.imageevent.com/sipphoto/samplepictures/T2i__3574%20edited.jpg

Hah, I was just messing around. :P I know the 400/5.6 is actually quite good for what it is. That moon is actually pretty good for a 100-400 (surprising, even). Probably a little sharper than these, which were all taken with a 300 f/2.8 L II + 2x TC III + Kenko 1.4x (840mm) and run through Nik Dfine 2 for cleanup:

http://i.imgur.com/HltlvDp.jpg
http://i.imgur.com/OjS8MX8.jpg
http://i.imgur.com/q6Gcwpv.jpg

Jackson_Bill

  • Canon 70D
  • ****
  • Posts: 268
    • View Profile
Re: 'Revolutionary' Dual Pixel AF Explained
« Reply #42 on: July 28, 2013, 12:11:46 AM »
Am i the only one who prefers shooting with the optical viewfinder, even if live view is tzhe same speed? I think its not long anymore til Canon only releases only mirrorless cameras if the AF speed is the same. And then people like me can pay another 899$ or whatever for an electronic viewfinder :(

No, you are not the only one. But, I am increasingly thinking I am more of a dinosaur than I realize (But then again, that happens every time I look in the mirror anyway).

I get that Canon is trying to make live view as useful and accurate as an optical viewfinder, but I hope they don't start to compromise optical viewfinder performance. Sorry, but I just don't see how live view can ever compete with the ergonomics of a viewfinder especially with longer lenses and in bright light.

....

I totally agree. Using the back screen to track action on the field, a bird in flight, or any other fast moving object just don't work. And I had a SONY with an electronic image in the viewfinder and (for us old guys) I definitely prefer something that doesn't require me to use readers.


canon rumors FORUM

Re: 'Revolutionary' Dual Pixel AF Explained
« Reply #42 on: July 28, 2013, 12:11:46 AM »

Ellen Schmidtee

  • Canon 6D
  • *****
  • Posts: 441
    • View Profile
Re: 'Revolutionary' Dual Pixel AF Explained
« Reply #43 on: July 28, 2013, 01:03:49 AM »
Am i the only one who prefers shooting with the optical viewfinder, even if live view is tzhe same speed? I think its not long anymore til Canon only releases only mirrorless cameras if the AF speed is the same. And then people like me can pay another 899$ or whatever for an electronic viewfinder :(

No, you are not the only one. But, I am increasingly thinking I am more of a dinosaur than I realize (But then again, that happens every time I look in the mirror anyway).

I get that Canon is trying to make live view as useful and accurate as an optical viewfinder, but I hope they don't start to compromise optical viewfinder performance. Sorry, but I just don't see how live view can ever compete with the ergonomics of a viewfinder especially with longer lenses and in bright light.

....

I totally agree. Using the back screen to track action on the field, a bird in flight, or any other fast moving object just don't work. And I had a SONY with an electronic image in the viewfinder and (for us old guys) I definitely prefer something that doesn't require me to use readers.

Just a thought - is fast moving too fast for a 3rd party firmware to lift the mirror and autofocus with dual pixel AF at a preselected location on the sensor?

Mark D5 TEAM II

  • 1D X
  • *******
  • Posts: 1195
  • Proud N0ink 0wnz0r / crApple iFruitcake H4t3r
    • View Profile
Re: 'Revolutionary' Dual Pixel AF Explained
« Reply #44 on: July 28, 2013, 03:14:47 AM »
Birds in flight, you say? If this video doesn't convince you how fast Dual Pixel PDAF on the 70D is, I don't know what will.  It can track a BIF over a field (2nd video from the top of the page, around the 0:46 mark): http://cweb.canon.jp/eos/lineup/70d/info/af-tech/index.html

After seeing this I'm even more convinced now about this revolutionary tech.  8)
Nikon NSF16 5-Leaf Dual-Blade Industrial Fan ¦ Nikon NTMFI-H1 Dry Heavy Flat Iron ¦ Nikon Tough Mama NTMRC1-2S Rice Cooker “Limited Edition” ¦ Nikon Tough Mama NTMJK18-S Stainless Electric Kettle Plate Type ¦ Nikon NHT 2-in-1 Curling Iron & Straightener in One ¦ Nikon N4004s Decision Master System™

canon rumors FORUM

Re: 'Revolutionary' Dual Pixel AF Explained
« Reply #44 on: July 28, 2013, 03:14:47 AM »