Tracking in Sony alpha 7 and alpha 99

[jfrabat]

Look into contrast detect versus phase detection AF. Look at lens maximum aperture values. Look at the size of AF motors and relative torque. Look at the number of AF points and whether they are cross-type sensors, or not. Look at the price of a top-level Canon or Nikon flagship camera ($6995 or so) versus an $800-$1400 body. And so on and so on. Look at Nikon's almost two decade lead in using color-value, distance-aware, and light reflectance analysis value metering technology (and Canon's newer system that ALSO uses color-aware subject mapping) and you'll see that there is a LOT of behind the scenes technology that the "other" camera makers do not have access to due to intellectual property.

Nikon's 3-D Color Matrix technology is something they invented years ago. It took Canon over 15 years to figure out a way around Nikon's intellectual property on focusing and metering--and Canon did that by developing a FOUR-color system, to increase their AF system's performance and metering reliability. In Japan, the amount of yellow present in greens is a type of "color"; Nikon used red-green-blue only, the 3 in 3-D Color Aware. Canon finally got a patented system that now makes their cameras no longer "color-blind", and it has proven to be a HUGE success in the new 5D Mark III, a camera that earlier in version I and II, had a particularly weak AF system. Now, with this new technology, it utterly kicks ass. Canon has a 20-year lead on Sony at making 35mm-srtyle SLR cameras.

Sony is an electronics maker that happens to make a few cameras. Nikon and Canon have been developing AF cameras for professional-level uses since the mid-1980's. Pick up a camera like a Nikon D3-series or a Canon 1D series, or a 5D Mark III. Those are Maserati's.

But if you wnt a fair comparison, you should not compare a mirrorless camera to a DSLR... in that case, you have to compare those high end Nikon and Canon to the A99 (or the newer A77 MKII if you want to talk about a crop sensor)... and both of those are rather fast focusing cameras. In fact, because of the translucent mirror, they can track better thn Nikon or Canon while shooting because only the Sony can continue to focus WHILE shooting!

And I dont think it is fair to say that Sony is an electonic maker that happens to make cameras... If you look at the last few years, most of the innovations in cameras have come from Sony, including those found in other brands (remmber how the D800 as a big deal because it was the firt 36MP DSLR? Was that not a Sony sensor in there?). I am not saying that one brand is better than another, but all have their strength adn weakness... I just feel that tracking and fast focus are actually Sony's strength (talking about the SLT cameras here, not the A7).

 

[haach76]

@Derrel
Sony is not a camera manufacturer but they gave us some of the best electronics out there, their TVs used to be the best (until Samsung came along) and even now they sell their image sensors to Nikon. Also their lenses are manufactured by Zeiss and their camera division was the old Minolta (if I am not mistaken). So there is no shortage of skills in sony for making great cameras.
As for contrast AF, lets focus on the phase detect AF. Lets look at alpha 77 M2 which has 70 AF points with 19 cross types (i think). Compare with a Canon/Nikon in the same price range and i think you will see the performance in AF is ... (i dont know, this is what i want to find out).

J

 

[gsgary]

And the sensor in the new Leica T is made by Sony

 

[Derrel]

@Derrel
Sony is not a camera manufacturer but they gave us some of the best electronics out there, their TVs used to be the best (until Samsung came along) and even now they sell their image sensors to Nikon. Also their lenses are manufactured by Zeiss and their camera division was the old Minolta (if I am not mistaken). So there is no shortage of skills in sony for making great cameras.
As for contrast AF, lets focus on the phase detect AF. Lets look at alpha 77 M2 which has 70 AF points with 19 cross types (i think). Compare with a Canon/Nikon in the same price range and i think you will see the performance in AF is ... (i dont know, this is what i want to find out).

J

Minolta had no patents on 3-D or 4-color metering, and Minolta went BROKE in the camera business: Sony bought a bankrupt camera maker's intellectual property when they bought the rights to Minolta's outdated d-slr concepts. "Zeiss" lenses are made by Cosina... Zeiss is nothing more than a "name", not a real manufacturer. It is "Pioneer by Centrex", not Harmon Kardon. It is Kia, not Rolls Royce.

Let's read a bit about the laggy electronic viewfinder in say, the Fuji XT-1, shall we, since you wonder why your college professors say pros are not keen on mirrorless cameras for focus tracking and all,shall we?

Fujifilm X-T1 Review - Overview
"I settled in at end of a short straight on the outside corner of a turn, so that the cars were coming straight towards me, and shot with the 55-200mm lens to frame tightly.From the time the cars took to traverse the length of the road, I'd estimate that they were moving at 25-30mph, which while not spectacularly fast, still meant a fair amount of focus adjustment to track with each vehicle. And as an added bonus, the speed wasn't constant either -- there was first acceleration towards me while I was trying to achieve a focus lock, followed by deceleration for the corner. (And I panned to follow each car through the start of the turn.)"

"Straight away, I hit my old "friend", the Fuji X-T1's easily-bumped exposure compensation dial. Reviewing my first few shots, I accidentally dialed in +2/3EV exp. comp. -- not enough to immediately notice through the viewfinder, but enough to clip the highlights under dappled sunlight through trees, since I was shooting JPEG-only at the time.
Fortunately, I caught the problem after a few cars, but it was a bit of a shame to lose these images, especially since one of the prettiest cars at the show was amongst them.
Another unwelcome surprise in those first few shots was the X-T1's viewfinder lag. I've praised it in my earlier shooter's reports, and for ordinary shooting it's exceptionally fast-reacting, by electronic viewfinder standards. When shooting bursts in Continuous High drive mode, though, it's much more bothersome.
I think what's actually happening is that the X-T1 isn't showing the live image between frames at all, just a review of the last image shot. It's something we've seen and commented on with other cameras before, but I must admit given the X-T1's otherwise-swift viewfinder, I wasn't expecting to see it here."

"...During Continuous High shooting, though, the delay soared to a full 10 frames of 60p video, or around 1/6th of a second.That lag made it quite tricky to frame accurately with the X-T1 in burst shooting. What my eye was seeing lagged what my hands were doing -- and with a fairly powerful telephoto, even the slightest twitch of my hands made a significant change to the scene. The result, initially, was that I'd overshoot my intended framing adjustment, then once I realized I'd done so a sixth of a second later, I'd overshoot a correction in the opposite direction. I felt more like I was chasing my subjects than framing them."

Yeah...mirrorless tracking...not quite up to OVF or OPTICAL viewfinder capabilities, due to lag...

 

[Derrel]

If mirrorless cameras were so,so good as some people think, Canon and Nikon d-slrs would be being dumped by the tens of thousands. Buuuuuuut they are not. Serious shooters the world over realize that for daiy-in-day-out "work", a Canon or Nikon d-slr is still the overall best tool yet invented for the majority of professional shooting requirements where the shot MUST be gotten.

It's not that mirrorless cameras are terrible, but they do have some issues, like lagging electronic viewfinders, and focusing systems that plummet from 4 frames a second to as low as 2.5 frames per second **if** you want FOCUSING with the firing (Sony, anybody?), or from 8 frames per second to 4, erratically-spaced frames per second with the Fuji XT-1.

 

[jfrabat]

If mirrorless cameras were so,so good as some people think, Canon and Nikon d-slrs would be being dumped by the tens of thousands. Buuuuuuut they are not. Serious shooters the world over realize that for daiy-in-day-out "work", a Canon or Nikon d-slr is still the overall best tool yet invented for the majority of professional shooting requirements where the shot MUST be gotten.

It's not that mirrorless cameras are terrible, but they do have some issues, like lagging electronic viewfinders, and focusing systems that plummet from 4 frames a second to as low as 2.5 frames per second **if** you want FOCUSING with the firing (Sony, anybody?), or from 8 frames per second to 4, erratically-spaced frames per second with the Fuji XT-1.

Here I have to agree; but this is not a Sony issue, as originally posted, but rather a mirrorless issue. And again, like most things, this is a tradeoff. You loose some functionality (and not only the focusing, but also all the direct access to functions with dedicated buttons vs menus, and even battery life), but you gain some benefits (mainly size). This is why I mentioned earlier that you need to compare apples to apples; if you are comparing to professional DSLR, the closest product Sony has is the A99 (and even though it is a great product, and as far as the OP is concerned, offers great autofocusing, it should be pointed out that the A99 is not targeted to "professionals" like the Canon and Nikon, but rather "prosumers"). The A7 and A7R offer great benefits, but were never intended to replace professional DSLR.

 

[nzmacro]

And people ask why I only stick to MF, gees

I shoot with guys (and one gal) that shoot with Canon, only 1 uses Nikon. Out of 6 bird shooters only one never complains about AF tracking and that's Steve using a 500 F/4 on a 1Dx. The 5D MKIII uses do complain now and then and so does Brian and Toya on the 7D's. Not that the 5d MKIII's and 7D's are bad, just sometimes they lose it and don't even seem to lock. The 1Dx, Steve has no issue with. They are darn good. The rest I hear swear words from all the time

Send me an A99 and a Sony 500 F/4 and I'll let you know.

Danny.

 

[haach76]

@Derrel
I tried to google this 3D color matrix and depth stuff but this is Nikon and Canon just using an off-sensor, smaller RGB sensor for metering which used to be like 1K pixels (only recently it has gone higher in resolution) and also use it for tracking and scene understanding. Sony mirrorless and translucent cameras dont have to use a separate RGB sensor for metering because there is no mirror and so they can use the main sensor for all that AI stuff. So i think this 3D color matrix is a bit of a hype or maybe i am not just getting it (I am truly a n00b so please correct me if i am wrong). You cant patent a color space, or the use of depth with color for tracking, so i dont know what is it they patented exactly.
Also this issue of lag in an electronic view finder. First of all sony introduced translucent mirrors to deal with this complaint, so now they have optical view finders. But lets just look at alpha 7. The lag in the digital view finder is there even if you are shooting with an optical view finder with canon. What you see in the digital view finder is what the sensor sees. So if you are shooting with a canon and obviously there is no lag in the view finder, your sensor might be behind what you see in that viewfinder. Whereas for a sony what you see is what you actually get. I think there is somethign very useful for having a digital view finder where you see exactly what your sensor sees. Having said that, i myself have not gotten used to the digital view finder. I had a canon long before a sony, so maybe its just resistance to new technology. Gary Fong had this video about how shooting with a mirrorless sony makes you a better photographer, i "think" (not sure) its because he said you get to know your camera better because of this "what you see is what you get deal".

@nzmacro
If I had the money to buy a 1Dx i wouldnt shoot birds. I would just sell the camera and buy exotic birds from the black market and watch them in the comfort of my house in a cage lol. But yea of course 1Dx is the real deal and I am not surprised that Steve is the only one who is not cussing