SL2-s autofocus

[BernardC]

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1 hour ago, MITDelay said:

From this article, Panasonic will stick to improving the contrast detection autofocus with DFD. If Leica continues to cooperate with Panasonicin dveloping SL cameras (which I think they will for awhile becuase of the L mount alliance), then maybe they will also stick with the CDAF for years to come. My assumption of course is that CDAF/PDAF is a hardware issue and not a software one so that Leica cannot just develop PDAF saftware to use on the cameras. I don't know enough to break that assumption.

Yes, phase detect is a hardware thing. PDAF sensors have extra elements on the sensor which determine if an subject is in-front-of, or behind, the plane of focus. This has benefits for autofocus speed, but not for accuracy. It has disadvantages too.

In the interview, the Panasonic executive states that they are working on technology to bridge the gap. I suspect that these are time-of-flight sensors, a technology in which Leica and Panasonic are both involved. ToF sensors draw a low-resolution distance map of a scene, which can be used to speed-up initial focus acquisition. This would compensate for the main shortcoming of CDAF: the fact that the camera doesn't know the direction of subject movement in the depth axis (it can do left/right, up/down just fine).

The L-Mount Alliance doesn't prevent the use of PDAF. Sigma uses a Sony PDAF sensor in their fp-l camera.

[MITDelay]

6 minutes ago, BernardC said:

Yes, phase detect is a hardware thing. PDAF sensors have extra elements on the sensor which determine if an subject is in-front-of, or behind, the plane of focus. This has benefits for autofocus speed, but not for accuracy. It has disadvantages too.

In the interview, the Panasonic executive states that they are working on technology to bridge the gap. I suspect that these are time-of-flight sensors, a technology in which Leica and Panasonic are both involved. ToF sensors draw a low-resolution distance map of a scene, which can be used to speed-up initial focus acquisition. This would compensate for the main shortcoming of CDAF: the fact that the camera doesn't know the direction of subject movement in the depth axis (it can do left/right, up/down just fine).

The L-Mount Alliance doesn't prevent the use of PDAF. Sigma uses a Sony PDAF sensor in their fp-l camera.

Truly informative. Thank you

Do you think even with the ToF sensors, it will be on par with canon's dual pixel PDAF? I mean, even if given time, does ToF sensors have that kind of potential? That would be very nice due to the fact that autofocusing (especially in video mode) is one of Panasonic (and Leica's) camera's biggest weakness.

I understand the L mount alliance does not prevent anyone in the alliance to use PDAF; however,  I suspect Leica depends heavily on Panasonic for the hardware development for the SL2, while Leica focuses on the software for their own cameras, given that the internal architechture is very similar to that of Panasonic's S1 series. That includes CDAF. Unless of course Leica will also cooperate with Sigma in making a camera, in which case we the leica customers will gain all the benefits.

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[BernardC]

57 minutes ago, MITDelay said:

Do you think even with the ToF sensors, it will be on par with canon's dual pixel PDAF?

ToF has some limitations, as does CDAF. ToF loses accuracy at long range, so it may not be the optimal solution for long telephoto work at/near infinity. Of course, knowing that your subject is near infinity may be enough information for CDAF to take-over.

One advantage of ToF is that it knows the distance to thousands of image points at the same time, and it can tell (to a certain extent) what those points represent. That could be great for video, where you could tell it to "switch focus between actor 1 and actor 2 every time I touch this button." It could follow them around a scene and never get confused by potted plants, beams, etc.

[beewee]

ToF sensors are useful at short ranges up to a few meters but have limitations at longer ranges primarily because it requires a light emitter. The longer the range, the stronger the emitter needs to be which consumes more power, generates more heat, requires better heat dissipation, gets bigger, etc…

The iPhone 12 Pro has a ToF sensor for auto focusing capability but I recall it also uses PDAF in addition to contrast detect.

[BernardC]

The main applications for ToF sensors are automotive and smartphones. The common smartphone use is to enable background blurring for selfies, which is the opposite of large-sensor camera requirements (they have too little depth-of-field, whereas smartphones have too much).  My intuition is that Leica's and Panasonic's implementation logic will be very different from what Apple is doing (not forgetting devices that implemented the tech before Apple did, of course).

I don't know any more than the average punter, but it seems like CDAF and ToF are complementary technologies. ToF provides an approximate distance measurement and, more importantly, a rate of change. That's the information that CDAF lacks; it would go a long way toward eliminating focus hunting. It probably doesn't matter if current ToF sensors provide exact measurements beyond 10m, they just need to tell the camera which way the subject is moving.

[sillbeers15]

SL2 + 90-280mm VE, AFC / Tracking mode

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[Jox]

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Hello,

The SL2S/90-280 set is very pleasant, with really pleasant renderings even in fairly low light, very much in the spirit of those of the R APOs such as 180F2.8 APO (doubled APO or not) for example.
Back to autofocus after a long time without it, I tried a lot of programming possibilities but I must not be at the top for a particular application: birds in flight at medium distance.

I'm at
- "AFc" focus mode
- "Pursuit" AF mode
- "Wild Animals" AF Profile / Focus 0 / Lateral Movement +1 / Direction Change +2

In fact, even there, I can't find the responsiveness of my very old Nikon D2x/70-200F2.8!
I would be very interested in sharing experience on this point.

Thanks in advance.