Has Canon solved the PDAF problem?

Started Jul 2, 2013 | Discussions
bill hansen
Veteran MemberPosts: 8,137
Like?
Has Canon solved the PDAF problem?
Jul 2, 2013

I notice the new Canon 70D claims to have on-sensor phase detection focusing ability, which (OSPDAF) has been the topic of several discussions in the NEX forum. Do any of the technologically advanced people here know if Canon's pixel-splitting approach is likely to resolve the PDAF "problem"?

-- hide signature --

Bill Hansen
Ithaca NY, USA

Canon EOS 70D
If you believe there are incorrect tags, please send us this post using our feedback form.
Keit ll
Senior MemberPosts: 2,817Gear list
Like?
Re: Has Canon solved the PDAF problem?
In reply to bill hansen, Jul 2, 2013

Read here :-

http://www.dpreview.com/previews/canon-eos-70d/3

This advance in technology &sensor design could be the reason why Sony think that it is the time to introduces mirrorless 'DSLR's ? There are obvious benefits to have reliable on sensor focussing providing that it is fast & reliable & Canon seem to have achieved this & brought about an improvement in Video focussing.

-- hide signature --

Keith C

Reply   Reply with quote   Complain
smallLebowski
Contributing MemberPosts: 536
Like?
Re: Has Canon solved the PDAF problem?
In reply to Keit ll, Jul 2, 2013

It's funny how Canon almost beat Sony in their own game. Sony was hoping to do revolutionary cameras getting rid of translucent mirror tech and going "DSLR" A-mount mirrorless in yearly 2014 and yet it is Canon that already produced a fully functional  DSLR camera 70D with OSPDAF which soon will hit the shelves. Canon did it in mid-2013 - at least half a year before Sony will come up with something.

Suddenly Sony has one more huge problem to deal with. It's a shame really. Maybe we have better situation with NEX? YEs, but with still missing announcement of long due replacement of NEX7 and no fast zoom - the same story and only rumors. It looks like Sony can give a good deal of rumors, but can't produce good staff in time. Oh, I'm sorry, was Sony planning to do it in yearly 2014? I'm sure there is plenty of time till 2014 and of course other camera manufacturers will just sit there and do nothing.

Sony - please put your s*it together and start making a good cameras now, not in 2014. Timing is critical.

Reply   Reply with quote   Complain
Keit ll
Senior MemberPosts: 2,817Gear list
Like?
Re: Has Canon solved the PDAF problem?
In reply to smallLebowski, Jul 2, 2013

One interesting statistic in DPRs writeup is that 103 out of 156 EF lenses are compatible with this new system of focussing , I wonder if Sony can do the same with compatibility ?

The remaining 53 Canon lenses use a hybrid system of OS phase + contrast focusing which will be a bit slower.

-- hide signature --

Keith C

Reply   Reply with quote   Complain
Atlasman
Regular MemberPosts: 424
Like?
Re: Has Canon solved the PDAF problem?
In reply to bill hansen, Jul 2, 2013

With this new technology, Canon will continue to fight off the mirrorless systems, using DSLRs.

Reply   Reply with quote   Complain
Keit ll
Senior MemberPosts: 2,817Gear list
Like?
Re: Has Canon solved the PDAF problem?
In reply to Atlasman, Jul 2, 2013

It's my understanding that the Canon 70D is mirrorless in a DSLR styled body ? It reads directly off the sensor & has an EVF.

-- hide signature --

Keith C

Reply   Reply with quote   Complain
tharwan
Forum MemberPosts: 50
Like?
Re: Has Canon solved the PDAF problem?
In reply to bill hansen, Jul 2, 2013

We will see if Canon did really solve this when they put it in the EOS M.

Nevertheless I believe that this  is the same thing that Sony had in mind. Maybe with some small changes like not only dividing the pixiels horizontaly but also some of them vertically to have some kind of cross type PDAF Sensor. Although I believe that like in CDAF the algorithms needed to use the capabilities these new sensor delivers play an important rule, specially when it comes to subject tracking.

Reply   Reply with quote   Complain
Keit ll
Senior MemberPosts: 2,817Gear list
Like?
Re: Has Canon solved the PDAF problem?
In reply to tharwan, Jul 2, 2013
Reply   Reply with quote   Complain
007peter
Veteran MemberPosts: 9,258Gear list
Like?
Anyone here know How Sony Hybrid Sensor in NEX-6 is different?
In reply to bill hansen, Jul 2, 2013

bill hansen wrote:

I notice the new Canon 70D claims to have on-sensor phase detection focusing ability, which (OSPDAF) has been the topic of several discussions in the NEX forum. Do any of the technologically advanced people here know if Canon's pixel-splitting approach is likely to resolve the PDAF "problem"?

I would say "yes" based on reading DPR's indepth explanation that canon's hybrid system cover the entire sensor rather than a tiny amount located near the center.

What I'm more interested to hear is how is Sony or Nikon hybrid sensor different.  For example, Nikon V1 is very fast while NEX-6 not as fast as Nikon.  What are the explanation for the speed differences?

 007peter's gear list:007peter's gear list
Nikon D3100 Canon EOS M Canon EF-M 22mm f/2 STM Nikon AF-S Nikkor 35mm f/1.8G
Reply   Reply with quote   Complain
Keit ll
Senior MemberPosts: 2,817Gear list
Like?
Re: Anyone here know How Sony Hybrid Sensor in NEX-6 is different?
In reply to 007peter, Jul 2, 2013

007peter wrote:

bill hansen wrote:

I notice the new Canon 70D claims to have on-sensor phase detection focusing ability, which (OSPDAF) has been the topic of several discussions in the NEX forum. Do any of the technologically advanced people here know if Canon's pixel-splitting approach is likely to resolve the PDAF "problem"?

I would say "yes" based on reading DPR's indepth explanation that canon's hybrid system cover the entire sensor rather than a tiny amount located near the center.

What I'm more interested to hear is how is Sony or Nikon hybrid sensor different. For example, Nikon V1 is very fast while NEX-6 not as fast as Nikon. What are the explanation for the speed differences?

Apart from possibly using different algorithms the Nikon has an advantage in that it uses a smaller sensor which has greater DOF at any particular setting similar to simple film cameras which had a near, middle & distant focus setting.

-- hide signature --

Keith C

Reply   Reply with quote   Complain
blue_skies
Senior MemberPosts: 7,056Gear list
Like?
Re: Yes .. read on - Canon is merely Fujifilm's masking cell technology...
In reply to 007peter, Jul 2, 2013

007peter wrote:

bill hansen wrote:

I notice the new Canon 70D claims to have on-sensor phase detection focusing ability, which (OSPDAF) has been the topic of several discussions in the NEX forum. Do any of the technologically advanced people here know if Canon's pixel-splitting approach is likely to resolve the PDAF "problem"?

I would say "yes" based on reading DPR's indepth explanation that canon's hybrid system cover the entire sensor rather than a tiny amount located near the center.

What I'm more interested to hear is how is Sony or Nikon hybrid sensor different. For example, Nikon V1 is very fast while NEX-6 not as fast as Nikon. What are the explanation for the speed differences?

Read this articicle first: http://www.dpreview.com/news/2010/8/5/fujifilmpd

It basically is the same sensor cell architecture that was already present in the X100, but the FW was not up to speed to leverage it.

Now in the X100S they have 'better' PDAF based focusing - but users still complain a lot.

The Canon system appears to be an identical copy of Fujifilm's solution.

The Sony system is a very different approach, and - reading the patent - should have more flexibility and have more sensitivity  Sony's sensing cells are larger (not single cell based), and masking them out requires some additional FW. Which system is 'better' imho does not depend on the sensing cells as much as it does on the processing FW. Sony's information seems a lot more precise than Fujifilms, but heuristics in software (in both) can make either system work, I assume.

My bet would be on Sony coming out with better FW to push the performance of their PDAF implementation. The rumors that the SLT is going to lose the pellicle mirror is an indication of this.

Also, if the rumors are true, the Sony technology will surpass DLSR technology - in fairness, the PDAF focusing system is as much as being able to detect phase shift as it is to decipher which focus point is the key one. On cell PDAF sensing produces a far greater sensing grid than dedicated PDAF sensors, but apparently also requires greater processor performance. This seems also true for Fujifilm (and Canon), in that the PDAF solution is not 'mature' yet.

I expect that next year we will have a lot of buzz about mirrorless PDAF based cameras. I assume that a FF Nex camera will very much depend on this technology reaching a level of maturity. (= match DSLR performance, both in speed and focus accuracy).

-- hide signature --

Cheers,
Henry

 blue_skies's gear list:blue_skies's gear list
Canon PowerShot S95 Sony Alpha NEX-7 Sony Alpha NEX-6 Sony Alpha 7 Sony a6000 +30 more
Reply   Reply with quote   Complain
Russell Evans
Veteran MemberPosts: 9,189
Like?
Live view AF in low light?
In reply to bill hansen, Jul 2, 2013

It will be interesting to see what the practical lowest EV value of the new on sensor AF is.  At 40mp, random noise in low light has to have some effect on the AF.

Thank you
Russell

Reply   Reply with quote   Complain
robert1955
Senior MemberPosts: 1,705
Like?
No, Canon's way is fundamentally different from Fuji's
In reply to blue_skies, Jul 2, 2013

Fuji half-masks a limited number of cells in the central part of the sensor. Those cells lose half the light to that mask.

Canon splits 80% of the pixels by giving them 2 photo diodes, facing L an R to make phase detection possible.

How well it works will become clear when tests become available. But is certainly a new approach.

So read this part of the preview: http://www.dpreview.com/previews/canon-eos-70d/3

blue_skies wrote:

Read this articicle first: http://www.dpreview.com/news/2010/8/5/fujifilmpd

It basically is the same sensor cell architecture that was already present in the X100, but the FW was not up to speed to leverage it.

Now in the X100S they have 'better' PDAF based focusing - but users still complain a lot.

The Canon system appears to be an identical copy of Fujifilm's solution.

Reply   Reply with quote   Complain
Tapper123
Senior MemberPosts: 1,163Gear list
Like?
Re: Has Canon solved the PDAF problem?
In reply to Keit ll, Jul 2, 2013

Keit ll wrote:

It's my understanding that the Canon 70D is mirrorless in a DSLR styled body ? It reads directly off the sensor & has an EVF.

-- hide signature --

Keith C

Hmm, I hadn't even thought of that, but I guess that's true!

Imagine a NEX 7 style camera with that focus system.

 Tapper123's gear list:Tapper123's gear list
RX100 III Sony Alpha NEX-F3 +2 more
Reply   Reply with quote   Complain
Richard Ettinger
Senior MemberPosts: 1,059Gear list
Like?
Re: Has Canon solved the PDAF problem?
In reply to Atlasman, Jul 2, 2013

Atlasman wrote:

With this new technology, Canon will continue to fight off the mirrorless systems, using DSLRs.

of course this incorrect.

the new tech only benefits "Live View" autofocus. through the viewfinder it relies on the best of canon's phase detection tech.

that being said, the implications for mirrorless cameras are enormous.

-- hide signature --

Canon 40D. Canon 50mm f1.4, canon 135mm 2.8/soft focus, Canon 70-200 f4L, Canon 24-105L. Sony Nex-7.

 Richard Ettinger's gear list:Richard Ettinger's gear list
Canon EOS 40D Sony Alpha NEX-7 Sony Alpha 7 Canon EF 50mm f/1.4 USM Canon EF 135mm f/2.8 SF +5 more
Reply   Reply with quote   Complain
Richard Ettinger
Senior MemberPosts: 1,059Gear list
Like?
Re: Has Canon solved the PDAF problem?
In reply to Keit ll, Jul 2, 2013

Keit ll wrote:

It's my understanding that the Canon 70D is mirrorless in a DSLR styled body ? It reads directly off the sensor & has an EVF.

-- hide signature --

Keith C

incorrect about the EVF

-- hide signature --

Canon 40D. Canon 50mm f1.4, canon 135mm 2.8/soft focus, Canon 70-200 f4L, Canon 24-105L. Sony Nex-7.

 Richard Ettinger's gear list:Richard Ettinger's gear list
Canon EOS 40D Sony Alpha NEX-7 Sony Alpha 7 Canon EF 50mm f/1.4 USM Canon EF 135mm f/2.8 SF +5 more
Reply   Reply with quote   Complain
nevercat
Senior MemberPosts: 2,353
Like?
Re: Has Canon solved the PDAF problem?
In reply to Keit ll, Jul 2, 2013

Keit ll wrote:

It's my understanding that the Canon 70D is mirrorless in a DSLR styled body ? It reads directly off the sensor & has an EVF.

-- hide signature --

Keith C

No this Canon is a normal DSLR with a normal mirror and a normal PDAF sensor and a normal OVF, the new PDAF chip only works in LV and video. ZI think Canon i not yet ready to use this technology in a DSLR styled mirrorless. We have to wait and see if this technology is good in fast focussing, low light or withaall lenses.

We also have to lok what happens to the IQ with over 49 mega pixels on one APS chip. Remember that every pixel is split in 2 for pdaf.

Reply   Reply with quote   Complain
Keit ll
Senior MemberPosts: 2,817Gear list
Like?
Oops !
In reply to nevercat, Jul 2, 2013

Sorry I was decieved by DPR's preview which didn't mention a mirror once !

-- hide signature --

Keith C

Reply   Reply with quote   Complain
tomtom50
Senior MemberPosts: 2,621Gear list
Like?
Re: Has Canon solved the PDAF problem?
In reply to smallLebowski, Jul 2, 2013

smallLebowski wrote:

It's funny how Canon almost beat Sony in their own game. Sony was hoping to do revolutionary cameras getting rid of translucent mirror tech and going "DSLR" A-mount mirrorless in yearly 2014 and yet it is Canon that already produced a fully functional DSLR camera 70D with OSPDAF which soon will hit the shelves. Canon did it in mid-2013 - at least half a year before Sony will come up with something.

Suddenly Sony has one more huge problem to deal with. It's a shame really. Maybe we have better situation with NEX? YEs, but with still missing announcement of long due replacement of NEX7 and no fast zoom - the same story and only rumors. It looks like Sony can give a good deal of rumors, but can't produce good staff in time. Oh, I'm sorry, was Sony planning to do it in yearly 2014? I'm sure there is plenty of time till 2014 and of course other camera manufacturers will just sit there and do nothing.

Companies who have on-sensor PDAF:

Fuji

Nikon

Sony

Canon

Companies that have actuall proven product with DSLR-level focus performance using on-sensor PDAF:

Nikon (1)

 tomtom50's gear list:tomtom50's gear list
Sony RX100 Canon EOS M Olympus PEN E-PM2 Sony Alpha NEX-3N
Reply   Reply with quote   Complain
DtEW
Senior MemberPosts: 1,792Gear list
Like?
Re: Has Canon solved the PDAF problem?
In reply to nevercat, Jul 2, 2013

nevercat wrote:

We also have to lok what happens to the IQ with over 49 mega pixels on one APS chip. Remember that every pixel is split in 2 for pdaf.

It might be safe to assume that IQ is going to be at least going to be equal to the prior 18mpx sensor (not a particularly high bar to be sure), as they are confident enough to boost native max ISO from 6400 to 12800, and expansion from 12800 to 25600.

NEX-5N/5R/6 - Exmor 16mpx, native max ISO = 25600, no expansion

NEX-7 - Exmor 24mpx, native max ISO = 16000, no expansion

D7100 - Toshiba 24mpx, native max ISO = 6400, expansion to 25600

D600 - Exmor(?) 24mpx, native max ISO = 6400, expansion to 25600

D800 - Exmor 36mpx, native max ISO = 6400, expansion to 25600

6D - 20mpx, native max ISO = 25600, expansion to 102400

5dMKIII - 22mpx, native max ISO = 25600, expansion to 102400

I have the 5N and 6D, and by my own unscientific seat-of-the-pants assessment, I will confidently use the 5N up to ISO1600 and accept ISO3200, while I will confidently use the 6D up to ISO6400 and accept ISO12800. The 6D is a high ISO monster.

(I tend to buy high ISO monsters because I prefer to scurry around in the dark.)

 DtEW's gear list:DtEW's gear list
Canon PowerShot G11 Canon EOS 6D Sony a6000 Canon EF 100mm f/2.0 USM Canon EF 75-300mm f/4.0-5.6 IS USM +16 more
Reply   Reply with quote   Complain
Keyboard shortcuts:
FForum MMy threads