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Could a new mirror-less sensor provide tracking focus superior to AF-D mode on the A99?

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Old Man River

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Although I have filmed only one soccer competition to date with the A99 in AF-D mode with my silver SAL-70400G, I noted a significantly higher percentage of "tack sharp" images compared to my previous extensive use of the same lens on my A77 in AF-C mode.

Considering the shallower depth of field on the full frame A99 sensor, I find these comparative sports action focus results all the more impressive.

That being said, limiting the discussion to focus modes only, could someone please explain how a future release non-SLT mirror-less FF sensor Alpha mount camera could achieve identical or superior motion tracking results relative to AF-D with the pixels doing double duty in only one focal plane?

Could it be that in the quest to win the DxO image resolution derby, the next generation Alpha mount FF camera might feature improved sensor noise elimination functionality with a concurrent incremental loss of robust focus mode functionality?
 
Solution
phaedin
without descriptions, explanations and specifications, all you have is speculation based on unknown or half baked facts.

so to answer your question.

Yes a new mirror-less sensor could provide tracking focus superior to AF-D mode on the A99.

The real question is "what generation of mirror-less sensor will provide tracking focus superior to AF-D mode on the A99?"

The answer to that is to be determined
My guess is PDAF/CDAF on Sensor will be Superior.

I think the Nikon V Aptina Sensor (Aptina / Sony patent share) shows it can do sports.

The million dollar question will be IF the first generation FF High Res PDAF/CDAF sensor will have better Sports AF vs a99? My guess is YES. Or why drop all SLT development and move aggressively to PDAF/CDAF , you don't do that without knowing something is in the cards.

In theory the Tracking can be Superior. Because it will be tracking using PDAF AND CDAF across the Full Frame. and BOTH is ON the Sensor , so no calibration errors (no separate location AF sensor). With the ability to use both contrast and Color information. More info across more of the frame should result in better tracking.

but, with more info ... there is also more Calculations ... and software to sort out all the info and Predict movement. D4 with two processors. My guess is Aptina has software that is very helpful to Sony on PDAF/CDAF. (and Nikon for that matter).

The a99 does not lock AF on moving targets as Fast and Track as solidly as Nikon talking any level of FF camera. So, it has a LOT of headroom for improvement. imho, Improvement vs the a99 "Needs" to be "a Given". Or Sony will not have moved forward on there AF. And they MUST, if they want to compete with N & C.

All the great benefits of PDAF/CDAF and EVF will be minimized by the big two if it cannot match or come closer to matching there AF. The EVF transition by all manf. hinges on the AF tech. and at what point it is "good enough". a99 is just a step Forward, a good one , but a Step.

That is the RACE on PDAF/CDAF Sensors. For the Top of the Food Chain level Cameras. DSLR like AF/CAF.

Look at all the complaints of why the RX1 is not PRO. It's has to do with the AF. The IQ is as good as ANY Full Frame Camera at any price with a 35mm lens. And the IQ alone is as good as "anything" FF at ANY Price.

So, will a PDAF/CDAF Sensor from Sony have better Sports tracking than the a99 ? I think YES ! Because it has to. NEED is always the mother of Invention.

Will it be on Sonys first shipped Full Frame PDAF/CDAF sensor? That's the million dollar question.

If it was easy , it would have been on the RX1/RX1 R. :)

Just my thoughts,

HG



Old Man River said:
Old Man River wrote:

Although I have filmed only one soccer competition to date with the A99 in AF-D mode with my silver SAL-70400G, I noted a significantly higher percentage of "tack sharp" images compared to my previous extensive use of the same lens on my A77 in AF-C mode.

Considering the shallower depth of field on the full frame A99 sensor, I find these comparative sports action focus results all the more impressive.

That being said, limiting the discussion to focus modes only, could someone please explain how a future release non-SLT mirror-less FF sensor Alpha mount camera could achieve identical or superior motion tracking results relative to AF-D with the pixels doing double duty in only one focal plane?

Could it be that in the quest to win the DxO image resolution derby, the next generation Alpha mount FF camera might feature improved sensor noise elimination functionality with a concurrent incremental loss of robust focus mode functionality?
Click to expand...
 
Another "potential" Benefit of PDAF/CDAF sensor for sports

with PDAF sensor spread across the entire frame with PDAF/CDAF sensors

Is , you can potentially look thru the EVF and Select a AF point on a Gorilla Glass "Touch" LCD and there be a PDAF AF point on pretty much anywhere you touch.

that could have tangible benefits beyond just sports tracking.

HG

Old Man River said:
Old Man River wrote:

Although I have filmed only one soccer competition to date with the A99 in AF-D mode with my silver SAL-70400G, I noted a significantly higher percentage of "tack sharp" images compared to my previous extensive use of the same lens on my A77 in AF-C mode.

Considering the shallower depth of field on the full frame A99 sensor, I find these comparative sports action focus results all the more impressive.

That being said, limiting the discussion to focus modes only, could someone please explain how a future release non-SLT mirror-less FF sensor Alpha mount camera could achieve identical or superior motion tracking results relative to AF-D with the pixels doing double duty in only one focal plane?

Could it be that in the quest to win the DxO image resolution derby, the next generation Alpha mount FF camera might feature improved sensor noise elimination functionality with a concurrent incremental loss of robust focus mode functionality?
Click to expand...
 
I'd have no problem upgrading to a mirrorless alpha-mount camera someday, if that's the shape of things to come:

Loading…

www.sonyalpharumors.com

Superior AF and better low light performance are two of the most important reasons I upgraded to the a99, and I think I'll be a happy a99 user for years to come. I don't know how good or bad the first of the mirrorless alphas will be, assuming rumors are true and those are what's coming. But what I can tell you for sure is that, if Sony wants my money, they'd have to give me a camera with even better autofocus (even in low-light or heavily backlit situations) than the a99, and even better low-light image quality as well. If they don't make progress on those fronts, then I'll keep waiting until they do, or upgrade to another system someday if they don't.
 
Wouldn't you need to be doing you action photography using the rear LCD as a touch screen to do as you describe? Seems like a terrible way to view, follow and photograph action as compared to a viewfinder, either OVF or EVF.

Right now the whole argument is a bit ridiculous considering we know nothing about it other than rumor and that so far mirror less focusing systems don't stand up well compared to current systems. Many are assuming Sony has made a major break through. Speculation is pointless until we see it in action.
 
...so here goes.

Obviously, there's a chance that it will be no better or inferior, for reasons already mentioned (for example the fact that the AF sensors go blind during exposure, compared to the SLT design).

But here's where a suggested mirrorless A camera can still improve on sensor AF greatly, to the point where it may beat the current AF-D dual AF system of the A99:
  • much faster sensor read out speed and/or higher frequency --> leads to faster AF and/or more precise AF due to faster and more data points within a certain interval
  • amount of AF points covering the subject during AF--> this can greatly improve precision simply due to having more data points per cycle, which even with all else being equal, could lead to a measurement with smaller margin of error. Obiously AF coverage of the whole frame is directly related to this one too.
  • a larger amount of AF points being read out continously, even before AF is activated and possibly around the subject --> a larger and more precise continually updated depth map than AF-D currently provides, can greatly increase speed and precision once the subject does enter the range of the depth map that was already registered.
  • more sensitive AF points on the main sensor --> better accuracy and speed, especially in low light than current
  • a much better predictive algorithm than used in the past. SLT's obviously rely much less on these, but they still do and former classic DSLR's certainly did. Canon and Nikon show that there's still a lot of improvement possible here too.
Most of these points are obviously highly dependable on processing speed etc. as well. And while I expect the least of a revolution on the 5th point mentioned, they could learn a lot from their new partner Olympus in this regard, since their CDAF system relies on predictive algorithms a LOT to track any kind of movement. It may not be competitive in this regard compared to a good modern DSLR, the fact that any CDAF system can even attempt to track action, is a testament to the smart algorithms that Olympus came up with.

I expect great strides on the first 4 points though, if the rumors and new lens releases point to the direction Sony is looking at. A large if though.
 
Last edited:
TrojMacReady said:
TrojMacReady wrote:

...so here goes.

Obviously, there's a chance that it will be no better or inferior, for reasons already mentioned (for example the fact that the AF sensors go blind during exposure, compared to the SLT design)
Click to expand...
Please forgive my ignorance, but why does a non-SLT design AF sensor have to be rendered "blind" during an exposure?

(Your many clearly articulated concepts are great food for thought!)
 
Old Man River said:
Old Man River wrote:
Old Man River said:
TrojMacReady wrote:

...so here goes.

Obviously, there's a chance that it will be no better or inferior, for reasons already mentioned (for example the fact that the AF sensors go blind during exposure, compared to the SLT design)
Click to expand...
Please forgive my ignorance, but why does a non-SLT design AF sensor have to be rendered "blind" during an exposure?

(Your many clearly articulated concepts are great food for thought!)
Click to expand...
Thanks for pointing out that ill formulated point. What it should have said is that AF points go blind when the mechanical shutter is active (closing) during exposure, which can be restricted to just a fraction of the total exposure time. But when shooting at fast burst speeds (which in theory should be easier without moving mirrors), it becomes more of a handicap in non SLT's.

That is, until electronic/global shutters take over. Which I think for large (APS-C and especially FF) sensors will take another few years. At least until resolutions have stabilized, since the former will require dazzling read out speeds to counter the usual artifacts (rolling shutter et al) that would impact stills.
 
Wally626 said:
Wally626 wrote:
Wally626 said:
Kiichiro wrote:
Wally626 said:
http://www.dofmaster.com/dofjs.html

--
AEH
http://aehass.zenfolio.com/
http://aehass.zenfolio.com/blog
Question: What do you do all week?
Answer: Mon to Fri. Nothing, Sat & Sun I rest!
Click to expand...
Thanks. I just tested using that site and a mobile app and you are correct.

I always though the dof is thinner on a FF than APS-C.
Click to expand...
If you taking a picture of the same object with the same focal length by moving the camera closer then the DoF is shallower with the A99, if you use the same lens at the same distance the DoF is deeper with the A99 since the view is much wider.
Click to expand...
Yeah, I forgot about that. I just tested it on my NEX and a99 and the a99 has thinner DoF because I have to move the camera closer to get the same FOV (using 35mm).
 
J Birn said:
J Birn wrote:

I'd have no problem upgrading to a mirrorless alpha-mount camera someday, if that's the shape of things to come:

http://www.sonyalpharumors.com/sr3-specs-of-the-new-a79-prototype-camera/

Superior AF and better low light performance are two of the most important reasons I upgraded to the a99, and I think I'll be a happy a99 user for years to come. I don't know how good or bad the first of the mirrorless alphas will be, assuming rumors are true and those are what's coming. But what I can tell you for sure is that, if Sony wants my money, they'd have to give me a camera with even better autofocus (even in low-light or heavily backlit situations) than the a99, and even better low-light image quality as well. If they don't make progress on those fronts, then I'll keep waiting until they do, or upgrade to another system someday if they don't.
Click to expand...
 
Dave,

it is possible (right now) to view thru the EVF ... and while doing that . use a TouchScreen LCD to select the AF point.

Sony just needs to use a Gorilla Glass (durable) TouchScreen LCD and FW the ability to have the LCD screen OFF but have the AF point selection on the LCD still active. While you live view thru the EVF.

It's all possible now. Not really something new.

New to a PRO camera.

Speculation and Discussion helps set Feature Priority's. Benefits and User level of importance.

These discussions are "Important" , "Before" the Specs are set. Not after.

If you are assuming that a active forum is not read by someone at Sony. My guess is that you are wrong.

fyi: I have had Nikon tell me about something I had posted. So, I knew they had clearly read it. And it also let me know they read it. :)

HG

dlkeller said:
dlkeller wrote:

Wouldn't you need to be doing you action photography using the rear LCD as a touch screen to do as you describe? Seems like a terrible way to view, follow and photograph action as compared to a viewfinder, either OVF or EVF.

Right now the whole argument is a bit ridiculous considering we know nothing about it other than rumor and that so far mirror less focusing systems don't stand up well compared to current systems. Many are assuming Sony has made a major break through. Speculation is pointless until we see it in action.
Click to expand...
 
Along with your mentioned OLY tech ... Sony can use Aptina's tech ... think Nikon 1 PDAF/CDAF.

My guess is there is a combination of Tech that Sony can test, combine and Use.

Have a feeling Aptina might have many things to contribute to the Software part. Which my guess is what Sony has been lacking in the CAF or First AF lock on moving subjects.

Seems like the Hardware is mostly there. More so if Sony has two processors.

imho, it's the total Sports Shooting Experience that it not quite there yet.

BUT, my bet is that SONY now has the Tech to do it. and can do it. We shall see.

I was thinking that Sony is about two generations off. but who knows , they might surprise and take that step in the Next generation of PDAF/CDAF. Sony certainly needs it.

Need is the mother of Invention.

HG

TrojMacReady said:
TrojMacReady wrote:

...so here goes.

Obviously, there's a chance that it will be no better or inferior, for reasons already mentioned (for example the fact that the AF sensors go blind during exposure, compared to the SLT design).

But here's where a suggested mirrorless A camera can still improve on sensor AF greatly, to the point where it may beat the current AF-D dual AF system of the A99:
  • much faster sensor read out speed and/or higher frequency --> leads to faster AF and/or more precise AF due to faster and more data points within a certain interval
  • amount of AF points covering the subject during AF--> this can greatly improve precision simply due to having more data points per cycle, which even with all else being equal, could lead to a measurement with smaller margin of error. Obiously AF coverage of the whole frame is directly related to this one too.
  • a larger amount of AF points being read out continously, even before AF is activated and possibly around the subject --> a larger and more precise continually updated depth map than AF-D currently provides, can greatly increase speed and precision once the subject does enter the range of the depth map that was already registered.
  • more sensitive AF points on the main sensor --> better accuracy and speed, especially in low light than current
  • a much better predictive algorithm than used in the past. SLT's obviously rely much less on these, but they still do and former classic DSLR's certainly did. Canon and Nikon show that there's still a lot of improvement possible here too.
Most of these points are obviously highly dependable on processing speed etc. as well. And while I expect the least of a revolution on the 5th point mentioned, they could learn a lot from their new partner Olympus in this regard, since their CDAF system relies on predictive algorithms a LOT to track any kind of movement. It may not be competitive in this regard compared to a good modern DSLR, the fact that any CDAF system can even attempt to track action, is a testament to the smart algorithms that Olympus came up with.

I expect great strides on the first 4 points though, if the rumors and new lens releases point to the direction Sony is looking at. A large if though.
Click to expand...
 
Not doubting your word but please explain the mechanics. Wouldn't you need to take your eye off the EVF to look at the touchscreen, or does the EVF show where you are touching the LCD?
 
All I can say is that with the delay of the Zeiss 50mm, maybe Sony can take that time to get out firmware to even allow use of the amazing AF-D with this lens -- would help warrant its hefty price!!
 
Dave,

Realize the a99 left side of the screen is a bit far away from the thumb, but for the left side you can also use your thumb of your right hand. but you can try it out even on a a99. (same as touching buttons on both sides, while shooting in the EVF)

I think Gorilla Glass is best , so there is less wear on the LCD touchscreen over time. (basically the same glass as used on a lot of Smartphones. On my Galaxy S it's been great. Durable as well. Dropped a few times.

Look thru the EVF , and just as you would use your left and right thumb to push the buttons on the back you can Touch screen the AF point.

When you do that the Single AF point would move. In Sports shooting I would probably choose a "Dynamic AF single point". In Nikon that would mean a Single AF point with the Points around it being Helper AF points - in both PDAF/CDAF. How wide the array can be a choice.

NOW currently, what I do is use the Joy Stick (as I do on Nikon) ... Center push to get to Center and then I already have muscle memory on how many clicks to get me to a certain AF point on the 3rd grid. Also on a sports shoot I am always in Crop mode. I like it because it lets me see around the crop and I get more reach , the AF points cover more of the crop. and I don't need res most of the time.

On this touch screen set up, when you touch you will see in the EVF what AF point you choose. a quick tweak can still be done with the Joy stick. But my guess is, with time and practice you will be able to move the AF with the touch of the screen pretty close to where you want to go with a reasonable amount of accuracy without looking.

fyi: on sports shoots I "try" not to move my AF point around too much. It's the major moves (across the screen) that a touch screen could help with. quick tweaks I am used to doing with the Joy Stick.

Then, when I am shooting "off the LCD" on a tripod , the touch screen AF point would be perfect. Some might even want to trigger on "the touch" at that point. I probably would not.

It would probably be similar when you Remote control your Camera via NFC/WiFi on your Smart Phone screen ...

All the LCD touch screen would be is another Option. That can be useful in a number of situations.

Digital cameras should offer more options and ways to do things. Just as the EVF opens up more options. A touch screen LCD could open up more Options, and maybe create a few new ways of doing the old things.

A good example for me going from OVF to Sony EVF is Peaking. In and of itself, it was just ok to me (at first). In normal shooting in Nikon I did not have a AF issue. BUT, start shooting with f1.4 lens. Turn on Peaking in the EVF , add in DMF then the usefulness Dramatically Changed for me. A Lightbulb went off. I cannot go back to shooting f1.4 lens without Peaking!

It takes a while to get used to, but it is changing the way I shoot. and how much I shoot at f1.4.

Will touch screen LCD change things like that. probably not. But it will change. and my guess is it will be used more and more. Smart phone users are already used to it.

Just months ago I was skeptical on EVF. even though I could mentally understand the benefits (down the road) , and felt it was way too slow.

For me , I think the Benefits of EVF are coming sooner rather than latter.

It's NOT like a Brand Change, changing from OVF to EVF is more of an adjustment. It takes "time" to get used to it and see the benefits in your every day shooting.

If say you have been shooting N & C OVF PRO gear.

Hope this helps,

HG

dlkeller said:
dlkeller wrote:

Not doubting your word but please explain the mechanics. Wouldn't you need to take your eye off the EVF to look at the touchscreen, or does the EVF show where you are touching the LCD?
Click to expand...
 
contax4ever said:
contax4ever wrote:

All I can say is that with the delay of the Zeiss 50mm, maybe Sony can take that time to get out firmware to even allow use of the amazing AF-D with this lens -- would help warrant its hefty price!!
Click to expand...
contax4ever,

I actually till recently did not know this lens could not do AF-D.

partly because in my shooting it did not come up.

Totally AGREE though that it's strange that on ANY lens Sony makes at this point that it would not support AF-D.

Really , AF-D is basically what Nikon does automatically in AF-C.

It's nice to know it a lens would be optimal for Fast Depth tracking ... But somehow my gut feeling is with PDAF/CDAF on the Sensor it might not be lens specific anymore?

If a lens is fast to AF , it's Fast to AF in SAF or CAF.

The new PDAF/CDAF Sensors and it's CAF software (Aptina/OLY/Sony) might change things. Probably for the Better "for SONY shooters". That's just a guess.

My expectation is that the CAF on the new PDAF/CDAF sensors will be better vs the a99.

Only time will tell. But, it's fun speculating. for me it's more fun than watching TV. :)

Hate to say ... but when I take a break on my computer from PP ... I am on the forums. bet I am not alone.

HG
 
This lens was in development at the same time as 70-400G2, so I believe that there may be some inherent barrier to AF-D working on this lens. I DO NOT just assume it will be taken care of through the next a99 firmware. I hope I am wrong, because I want this lens but with the highest level of functionality. I need to know with certainty that AF-D will be possible with it; if I know that, I will buy it now (even if I have to be wait a few months for the FW update).
 
contax4ever,

You are probably right on the a99 AF-D.

What I am more concerned about is it's performance on the New PDAF/CDAF sensors. Which "might" clearly outperform the a99. That's my expectation.

So, my greater concern is how the new 50mm f1.4 ZA SSM works with that. If the delay has to do with anything matching up with Sensor performance or camera performance it is because of that "release" of the new cameras PDAF/CDAF sensors, and NOT the discontinued a99. Harsh for a99 shooters , but that is my guess.

The Success or failure of the Sony Camera Div. "probably" depends on the PDAF/CDAF Sensors and lens in 2014. not the a99. Regardless of what anyone says about how it met expectations, a have doubts that it made "Bank" (a clear financial and PR success that you would build on it). It's obvious what did , RX100 and RX1.

fyi: the 50mm f1.4 ZA SSM is pretty Fast on AF at night ... so Day it should blaze. This weekend I might have a chance to take it out with the a99 on a Triathlon. For me , Bikes is a good test.

And at 50mm even at stopped down to f2.8 ... at how close they will be ... it should be interesting.

I am kinda thinking if it can handle bikes in close , nothing on a normal every day shoot should be a challenge for it. AF-D or not. and I am a little more familiar with the a99 now.

Nikon D700 (old) and the D800 (36mp) and of course the D3/D4 does not have a separate AF-D mode. and frankly it can run circles around the a99.

Don't get me wrong , I agree with you "totally" ... ALL of Sony new lens should have AF-D support if it is important. The question will be , is it important on the new PDAF/CDAF sensors?

and will it take special AF-D optimized lens to take advantage of it? Hmmmm that's the question I am curious about.

Just my thoughts,

HG

contax4ever said:
contax4ever wrote:

This lens was in development at the same time as 70-400G2, so I believe that there may be some inherent barrier to AF-D working on this lens. I DO NOT just assume it will be taken care of through the next a99 firmware. I hope I am wrong, because I want this lens but with the highest level of functionality. I need to know with certainty that AF-D will be possible with it; if I know that, I will buy it now (even if I have to be wait a few months for the FW update).
Click to expand...
 
Hawaii-geek said:
Hawaii-geek wrote:

Really , AF-D is basically what Nikon does automatically in AF-C.
Click to expand...
Can you please explain this contention more fully? I'm sure you are correct, but I'd like to understand how this can be so due to the lack of SLT implementation by Nikon.
 
Old Man River said:
Old Man River wrote:
Old Man River said:
Hawaii-geek wrote:

Really , AF-D is basically what Nikon does automatically in AF-C.
Click to expand...
Can you please explain this contention more fully? I'm sure you are correct, but I'd like to understand how this can be so due to the lack of SLT implementation by Nikon.
Click to expand...
OldManRiver,

I do not know all the tech details of it. but basically Nikon already uses Color information and PDAF information to track.

BUT, it's not the Tech ... It's the Results that count imho.

Even on a 36mp D800 with a 70-200mm f2.8 VRII mounted ... there is no question in my mind that the D800 in CAF runs circles around a a99 in any mode.

That just the way I see it. and have experienced it.

I have taken the a99 out on a shoot that I have done many times before with a Nikon.

Let's just put it this way. of over 1,000 shots on the Nikon set up I missed maybe 2 shots. And it was probably because I was pushing it and shuttered to soon. The Nikon has a Fast trigger in CAF Focus + Release Priority. Dynamic AF point. Single AF point.

There is a reason why I was flown to the Tokyo Marathon to shoot it (with my Nikons). :)

But, don't get me wrong. the a99 is new to me. And it is VERY good on AF. Note my post on shooting f1.4 on the new 50mm f1.4 ZA SSM.

It's just that I am not totally sold on the CAF / D-AF ability of Sony just quite yet.

But, I do think they are close and can do it.

Just my thoughts as a PRO Nikon Sports Shooter.

Thank you,

HG
 
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