September 18, 2014, 10:08:39 AM

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Messages - sarangiman

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EOS Bodies / Re: How can we improve on 5D3 to 5D4?
« on: Today at 04:00:56 AM »
When it comes to the A7r, for me, it would be used solely for landscapes. I've said that on many occasions. That's also a big part of the reason why the D810 is not the most appealing's a very pricey camera, on top of the need for new lenses (which just skyrockets the price even more)...just for landscapes.

Again, my goal is NOT to replace my entire Canon kit. I'm not "moving" to the A7r...I would simply be adding the A7r. I would be adding it very specifically just for landscapes. From what I know about the shutter shock issue, it primarily affects longer focal lengths when used on a tripod when there isn't enough weight to keep everything steady. A lot of people (particularly on DPR forums) have asked about it, and a lot of people who own the A7r have replied saying they have never encountered the issue at all. I have no intention of trying to slap my 600mm lens on the A7r, nor any other long focal lengths. I might like to try it a few times on the A7s, but I have no expectations that the AF system would work well through the metabones adapter. Maybe someday, but that isn't my goal right now...and if Canon can remain competitive at high ISO, it never will be.

The A7r would pretty much exclusively just be a wide to ultra-wide angle landscape camera. Maybe some macro stuff in the long run (with an MP-E 65mm, if the thing would work with the adapter.) The vast majority of my work with it would be 16-35mm, at the wider end, which should reduce the impact of any potential SS issue even further.

Right, that's why I was saying it might make sense for you. As an additional camera for your landscape work. I've found shutter shock to *not* be an issue under ~70mm focal length, but of course that depends on your tripod, setup, etc. So you'll be fine with the 16-35 & the A7R. Btw, once you hear & feel the shutter on it, you'll no longer be surprised that SS is actually an issue... but it's easily demonstrated as well now that the 70-200 FE is out.

I'd worry about macro work on the A7R - I'd expect shutter shock to be an issue, since macro is just as affected by camera shake as telephoto. Unless you're using a flash.

That MP-E 65mm is fantastic. I've still got mine & intend to use it with that A7 I'm always toying with the idea of buying...

EOS Bodies / Re: How can we improve on 5D3 to 5D4?
« on: Today at 03:55:50 AM »
You know, I thought of a potential reason why sports photographers may not talk about or use 3D tracking. If there are multiple players wearing similar jerseys far enough away that the detail discerned is not specific enough to any one player, this might confuse the AF system, and it may jump from player to player.

Here, the arguably less sophisticated system of the 5D3 (or 1D X with iTR off) might actually have an advantage: b/c these algorithms usually look for the concomitant loss of one subject at a particular subject distance and the appearance of a subject with similar subject distance elsewhere.

Now I'm really curious to see if iTR turned off works better for this type of shooting than iTR turned on/Nikon's 3D tracking. But again, as I said earlier, I don't think sports are the best use-case for 3D focus tracking to begin with.

Anyway, perhaps that's at least part of the reason for some of the general lack of awareness and enthusiasm for 3D focus tracking. Furthermore, Google searches on these topics indicates there's quite a lot of confusion re: iTR/3D tracking and when and when not to use it. So I'm rarely moved by the 'if this were so great, wouldn't people be raving about it?' argument - people do find interesting ways to use technology that aren't immediately adopted or known in a widespread fashion.

In fact, it's kind of funny, but, Canon's own Rudy Winston in his technical article on iTR (dated just last year), writes:

  • "The EOS-1D X is the world’s first SLR with the ability to perform Face Detection when using the standard eye-level viewfinder (all previous D-SLRs with face detection capability could only do it during Live View operation, when the camera’s actual imaging sensor was used to read the scene)."
  • "While this new metering sensor is used to fine-tune exposure metering, Canon’s engineers realized that its ability to recognize subjects could be used in other important ways too. [for subject analysis]"


Well, I suppose he'd never picked up a Nikon... as those were both previously available, for many years. I mean the statement "all previous D-SLRs with face detection capability could only do it during Live View operation" is flat out false, unless you were to interject 'Canon' after 'previous'.

So if Canon's own people don't know, please excuse me for being skeptical re: whether or not that many people actually know how useful 3D focus tracking and scene analysis off the RGB metering sensor can actually be. Save for those that have thoroughly tried and tested both (or more) systems.

EOS Bodies / Re: How can we improve on 5D3 to 5D4?
« on: Today at 02:53:16 AM »
Well, at this point all I can say is that we'll have to agree to disagree. I hope you understand my intention of challenging generalizations. In all seriousness, thanks for refraining from emotional posts, and having more of a dialogue.

As for the AF tracking thing - I haven't been changing my story, but given the volume of posts, I don't blame you for seeing it as such. But I also don't think any more text is going to do any convincing, so I'll rest my case there. My initial purpose of the AF stuff was to challenge the assertion that the 5D3 AF is clearly superior to the D800 AF, and I think I made my points re: that pretty clear. I'll rephrase my initial 'opinion' that the 5D3 is almost useless for reliable subject tracking to (and you're right, that is more my opinion than a stated fact): Nikon's recent DSLRs have significantly more reliable, accurate, and robust subject tracking across the frame than any Canon DSLR I've tested to date, though the 1D X comes close. And it's b/c the secondary color sensor undoubtedly helps tell the AF system what to track. Without this, the AF algorithms are rather blind in that they can only work with a map of detected subject distances at any given AF point at any given instant, not have any understanding of what those subjects are in order to track them.

As for the Sony A7 series for your Canon glass - that's not a bad option. The Metabones Smart Adapter III is pretty darn good, if you can work around some of its quirks. Don't expect fast or professional AF, of course, but it could work for your landscapes (the AF is not going to work for your bird photography). Unfortunately, shutter shock is a real issue with the A7R, and since it seems you like telephoto shots, I don't think the A7R will work for you. The A7 will work; I doubt you'll like the A7S b/c it has worse base ISO DR than the A7R... and it's pretty obvious in landscape shooting when raising shadows (it's still better than Canon, but if you're picking up a body to avoid low DR, then... that's not the right one). That plus its resolution cost, all for a tiny bump in ISO performance at the highest ISOs (I really only see a significant benefit at ISO 25.6k and above).

I myself have toyed w/ the idea of having an A7 + 'f/4 holy trinity' of 16-35 (now that it's released), 24-70, and 70-200 as my travel/landscape camera. But keep deciding wavering - b/c I'm not sure the size/weight benefits outweigh the downsides enough. And now there's a system where you can say the lenses don't seem to take full advantage of the 36MP the A7R offers (not that the 70-200 could, b/c of shutter shock), yielding numbers not far off from Canon 5D Mark III + similar lenses. I must say, though, it's really cool that you can hold a A7 + 24-70 far above your head, swing it around like a toy, get some high up vantage points, etc., and never feel a single ache/soreness in your hands/arm!

Not to beat the Nikon drum again, but, the D810 with electronic front curtain is the only way I know of getting the most out of a 36MP sensor currently. Plus it has a half to 2/3 EV more DR than the A7R, b/c somehow Nikon squeezed out higher effective FWC per-pixel from what ostensibly seems to be a similar sensor. But I can understand your desire to select a system that'll use your Canon glass. It's just that the A7R probably isn't it. Shutter shock was actually the reason I got rid of my A7R. Yes you can mitigate it to some extent by strapping massive weights to your camera, but (a) that defeats the purpose of the system, and (b) that's just not something I want to be worrying about when there's clearly a better alternative.

EOS Bodies / Re: How can we improve on 5D3 to 5D4?
« on: September 17, 2014, 10:42:46 PM »
You should know, though, that you do come off as a very strong Nikon fan, given that you regularly seem to try to insinuate that Canon technology is inferior to Nikon technology...for pretty much every technology these kinds of cameras have. I haven't ever really seen you argue that anything Canon does is better. I've seen you make one-liner statements kind of to that effect, but when it comes right down to seem to think Nikon is superior in every respect. That perfectly fine, everyone has and is entitled to their own opinions and preferences...but, it does come off a certain way. It comes off to me the same way I must come off to you, only the brands are switched. :P

I see what you're saying, but here's why it's like this:

I come in and specifically counter some false generalization that Nikon X is worse than Canon X (like the D800 AF is inferior to the 5D3 AF). That requires pages and texts of explanation, b/c no one here wants to accept it. You won't even try the Nikon out, resorting to some basic tests with your Canon that may or may not correlate with the real-world shooting scenarios where I've tried both systems. So I try to explain, post videos, then eventually give up.

OTOH, I only provide 'one-liners' when it comes to a superior Canon tech (dual cross-type points providing more potential detail to focus on, wider base-lines providing more accuracy, potentially anyway, the wireless flash system, etc.) b/c no one here is making some false generalization about those being poor or worse than Nikon. And, naturally, since this is Canonrumors, where Canon people reside who don't want to think they made the wrong decision (that included me for many, many years - and if you must know, I still have my 5D3 and will continue to have it until I've convinced myself from empirical data that Nikon is not noticeably worse in AF precision with 24/35/85 primes - though Roger Cicala's initial data suggest the systems are comparable). For now, though, the D810 has solved many of the problems people have asked solutions for here, while introducing little to no negatives (yet).

So in the end it boils down to this: I don't need pages of text to convince you that Canon is better in one respect or the other. You'll gladly digest it in one line, one phrase even. :) Something Nikon is better at? Not a chance, without writing a novel & presenting irrefutable data. Which, obviously, I can't do. That's fine. But I am glad I refuted the general statement that '5D3 AF is clearly superior to D800 AF', b/c maybe that'll actually make someone try the systems out before being misled by a generalization that may or may not be applicable to him or her.

Make sense now?

EOS Bodies / Re: How can we improve on 5D3 to 5D4?
« on: September 17, 2014, 09:45:50 PM »
What I've denied is your claims that Canon's AF system in the 5D III cannot do certain things. I tested those things. My 5D III performed fine doing AF with the 16-35mm f/2.8 with close, moving subjects. It's not 100% perfectly accurate, but I'm sorry, I don't believe for a moment that the Nikon system is 100% perfectly accurate either.

But that's not what I claimed. I said that, especially in comparison to Nikon's 3D focus tracking, it's ultimately so unreliable as to be practically useless for my shallow DOF wedding photography using fast 24/1.4 and 35/1.4 primes. Because I could not trust it. It gets confused too easily, and this'd come as no surprise if you performed my little thought experiment on how the algorithm actually works. And I'm *not* alone in my opinion. Sure, rewind 10 years, and the 5D III's subject tracking would've been the best thing since sliced bread. It's a very cute, clever algorithm. And I think it still works quite well for sports. It just hasn't kept up with what the metering sensors in the 1D X and Nikon's can do, or what the imaging sensors can do in mirrorless cameras now (although without phase detection, the latter are still lagging IMHO). Arguing against this is literally arguing against the benefits subject recognition via a sensor bring. And, again, you'd know this if you just picked up a D810 & put it in 3D tracking and waved the camera around a bit. It sticks to subjects almost as well as the Sony AF method you praise.

As for the lens stuff, there's too much to respond to, but generally my entire point of those examples was this: I pulled a few of the lenses I own to show you that your statement that generally Canon lenses are better clearly requires more proof. Old lens design, new lens design - I picked both, you're still going to find something to complain about. But my point stands - you can't just go and say that generally a 5D3+Canon lenses will outresolve a Nikon D800E+Nikon lenses. That statement needs proof, b/c I easily pulled up 4 examples proving otherwise. And it's ridiculous to suggest anyway - that a sensor with literally 50% more resolution is somehow going to perform worse when paired with similar, high-end lenses.

Also, I wasn't referring to the overall DxO score; I was referring to the P-MPix score, which takes into account lens MTF & sensor resolution and characteristics.

In case you haven't sensed a them here yet over the years - I'm fighting your general claims. Like Canon high ISO is better (glad we've dispensed with that finally!), Canon lenses are better, Canon sensors have more DR at higher ISO, Canon lenses + a 22MP sensor somehow still generally outresolve Nikon lenses with a 36MP sensor, etc. etc.

These claims are misleading.

Also, I'm not a Nikon fan. I'm a fan of some of the technologies Nikon uses, as well as some of the technologies in the Canon system (dual cross-type, wider baseline, wireless flash, DPAF). I'm a technology proponent. Therefore, I cringe at false generalizations that ignore the realities of better, and worse, technologies.

EOS Bodies / Re: How can we improve on 5D3 to 5D4?
« on: September 17, 2014, 08:24:01 PM »
They seem to aim for building the smallest, tightest bodies possible for every single model.

Some find that preferable.

Their ergonomics don't fit my hands well (it's like they were designed explicitly for people with really tiny hands...I have rather large hands).

Fixed in the D810. I used to have the same complaint, as I also have big hands.

Nikon has a couple lenses that I think are very nice, like the 14-24, but in general it doesn't seem like Nikon glass overall is up at the same level as Canon glass...and lens testing often demonstrates this. Canon lenses on say the 5D III resolve as much or more measurable resolution in output images than Nikon lenses on the D800/D810 most of the time.

Right... yet another urban legend. Like the 'Canon high ISO is the best!' one.

So let's recap the above data which directly contradict your statement "Canon lenses on say the 5D III resolve as much or more measurable resolution in output images than Nikon lenses on the D800/D810 most of the time.": 60% increase in effective resolution going from the 5D3+16-35 to the D800E+14-24; 43% increase going from 5D3+70-200 to D800E+70-200; 38% increase going from 5D3+35L to D800E+35G. I can hear it already: it's DxO so it must be wrong & biased, right? It's not at all possible that a higher resolution sensor (no AA filter) with a modern lens design actually gives you, er, higher resolution, is it?

These broad generalizations are just silly. Which is why I don't make them. I've only been pointing out the very specific arenas in which Nikon offers advantages. You've been pretty unwilling to accept some of them (like the advantages of a separate RGB metering sensor - even in the Canon line itself) without even trying yourself.

Further more, while you always have glowing things to say about pretty much everything Nikon, not everyone who has used them has so many good things to say.

Like when I complained about missing Canon's plethora of cross-type points, wider-baseline dual-cross-type central sensors, some of their glass, and their wireless flash system?

In my posts of late, I've simply been calling out the arenas in which Nikon is better, not saying Nikon is better in every regard for everyone.

You of all people should understand that, as you & I have the same end goal - we want a system that has the best of both.

Reviews / Re: Tony Northrup - D810 vs. 5D Mk3
« on: September 17, 2014, 05:01:37 AM »
Maybe this video released by Sony will help get my point across:

Note how at 1:33 they stress how the AF system doesn't get 'distracted' - because it understands its subject from scene analysis of the imaging sensor. Same thing with the RGB metering sensors in the 1D X, and in Nikon cameras (albeit with much less resolution). And that has been my point all along.

Perhaps on-sensor PDAF and/or DPAF will eventually outperform what we see with DSLRs. I'm all for that. But for now, the best subject tracking is available in cameras that *have* a dedicated color sensor for subject tracking. Be it an image sensor, or a dedicated RGB metering sensor. Not a camera like the 5D Mark III that lacks both of these inputs when it comes to subject tracking.

EOS Bodies / Re: How can we improve on 5D3 to 5D4?
« on: September 17, 2014, 03:07:03 AM »
Falk Lumo did some great work that showed AFMA inconsistencies across the AF sensor, on top of a skew that resulted in the left AF problem:

This is taken from his article here:

That looks like lens manufacturing issues to me where the lens isn't properly centered. Look at the recent lens testing on lensrentals to see how warped the light coming through the lens is. It would appear that this warping of light does more than impact IQ, it also impacts AF.

That is unless the above AFMA AF mapping is the same for every lens on that camera ... seems more likely to be a lens manufacturing issue than camera one.

Has anyone done a similar test for a Canon lens/camera combination?

Dilbert - I believe what Falk Lumo was showing there was the AF sensor miscalibration fiasco Nikon underwent with the D800.

I do know Roger's (incredible, laudable, and informative) work - yes, the PDAF sensors are making measurements from non-central light rays, and have to then be corrected for the image-forming light which uses both central & non-central rays. This is lens-specific, and also, at least partly, where AFMA comes in.

My point was: manufacturing tolerances are not so tight that you can assume that the AF sensor surface is perfectly flat, or that it's perfectly aligned compared to the image sensor. Therefore, different focus points may need different AFMA values for optimal focus, and who knows - this might vary from lens to lens as well. We really just don't know exactly what AFMA is doing, or the math involved, although some suggest it's a correction to that correction value that corrects for the PDAF sensor's non-central light-ray measurements. Which itself will be dependent upon the degree of spherical aberration for any given lens.

I wonder if Reikan's developer has collated this sort of data from people using his software... would be incredibly interesting.

EOS Bodies / Re: How can we improve on 5D3 to 5D4?
« on: September 17, 2014, 02:55:37 AM »
So... I'm just wondering how many here realize that the D810, D800, and D750 already have every single one of those features...
Perhaps just the few of us who've actually made the switch and learned what features our new toys, uhm, tools possess.
Frankly, many of those cool features I rarely have use for.  I merely moved to get much improved raw files for landscape work.
I do want to borrow a buddy's 150-600mm Tamron and try the D800's AF tracking for BiF shots.
I don't care if I don't have a high frame rate, just good focus.

Haha, well said.

Initially I'd wanted to switch for the RAW dynamic range, which is great for landscapes, as well as for exposure latitude in post-processing. But then I realized just how powerful all those other features are.

Particularly: subject tracking in 3D focus tracking mode. Which I never used on the 5D3 b/c it was far too unreliable, no matter what use-case I chose in the menu nor how I optimized any one of those use-cases.

But then there's also programmable auto ISO, which is so much better than constantly having to manually change the minimum shutter speed as I switch primes at a wedding (since the 1/focal-length rule is not always applicable).
And now b/c of the ease of EC in M mode with Auto ISO - and b/c of the incredible sensor performance - I rarely have to worry about blown highlights even in high ISO situations b/c I just dial in a massive amount of negative EC. In low light scenarios that'd require ISO 800 and above anyway, this usually means I'm not paying any shot noise cost by dialing in negative EC, since all it's doing is lowering the actual ISO amplification used (not changing the focal plane exposure). So, for example, instead of ISO 1600, EC -3 will use ISO 200. Since downstream read noise is low, I pay very little (albeit non-zero) noise cost compared to just using ISO 1600. Meanwhile, I gain 3 stops of highlight detail b/c of the lower ISO. I then selectively raise exposure in post, protecting highlights.

The funny thing is: if Canon were to properly implement EC in M mode with Auto ISO, I'd actually use it in an opposite manner to what I described above. In other words: to brighten the image (via ISO amplification) to near where I want the final image brightness to be, not to apply negative EC - since there *is* a noise cost to brightening in post-processing vs. raising the ISO in-camera. So one could make the argument that if any of these cameras needs EC in M mode with Auto ISO, it's Canon, not Nikon - with the latter you can just select your shutter speed and aperture, then dial in a relatively low ISO and then choose your exposure in post-processing via the exposure slider.

Anyway, I'm rambling now.

What Canon stuff do I miss?
I do miss cross-type points all over the frame, the wireless flash system, and some Canon glass, though. And sometimes I get the feeling that Canon's center AF point focused faster and more confidently in very low light than the D810 - which wouldn't be surprising. Although both systems are rated down to EV -2, the 5D Mark III is 'looking' for much more detail with its horizontal, vertical, and dual-diagonal sensors.

EOS Bodies / Re: How can we improve on 5D3 to 5D4?
« on: September 17, 2014, 01:21:18 AM »
My list...designed to be the all-arounder:

 - Histogram based on RAW *!* (screw JPEG! :P)
 - Higher frame rate (8fps, using CP-ADC for low noise, high speed readout)
 - More dynamic range (high and low ISO...two stops low, as much as possible high)
 - More resolution (~50mp)
 - Layered sensor (drop the bayer! with binning capability, so I could bin 2x2, 3x3, maybe even 4x4 for very high ISO, as I'd rather have the SNR than anything :P...yes, this would mean 150 million photodiodes)
 - iTR metering
 - f/8 AF with center zone support (say 13 center af points usable at f/8)
 - AF-point linked meter
 - DPAF-automated AFMA (and, therefor, DPAF)
 - Dual CF (w/ CFast2 support)

"iTR metering"?  :o

iTR is the AF tracking mode that uses the metering sensor for subject recognition and tracking...

I must say, I'm quite surprised at the number of people in this thread asking for:

  • More DR at base ISO
  • More resolution
  • Spot metering linked to AF point
  • Programmable Auto ISO
  • EC in M mode (and while we're at it: in a less stupid implementation than the 1D X's)
  • Face detection & tracking outside of Live View
  • ... and at least one guy asking for better subject tracking across the frame after initially choosing a subject (well that makes 2 of us now, since this is one of my wishes as well)

So... I'm just wondering how many here realize that the D810, D800, and D750 already have every single one of those features...

Or perhaps that's the point - everyone here wants what Nikon already offers? Either way, it's kind of funny :)

I'm going to add one more thing to the list:

- AFMA for every single AF point, and then, yes, DPAF/CDAF-automated AFMA... b/c AFMA is already incredibly annoying as it is - imagine doing it for 65 points!

I want this b/c I'm finding more and more that you can't trust the factory calibration process to have calibrated every focus point perfectly.

Falk Lumo did some great work that showed AFMA inconsistencies across the AF sensor, on top of a skew that resulted in the left AF problem:

This is taken from his article here:

EOS Bodies / Re: How can we improve on 5D3 to 5D4?
« on: September 17, 2014, 12:53:47 AM »
I would also like to have autofocus track a moving subject in a frame without me having to use the joystick (Nikon can do this as well).

Wouldn't that just be enabling the mode that uses all 61 points?

+ servo, yes.

I think he means 'Intelligent Tracking and Recognition', or iTR, using the RGB metering sensor - which does this far more accurately and reliably, for certain shooting scenarios, than the 5D Mark III ever could. The metering sensor also enables 'face detection AF in viewfinder. Exposure/Ettl based on face alone' -- which PhotoCat wanted. And enables spot-metering linked to the AF point as well.

Canon DSLRs below the 1D X have been behind in all these regards compared to Nikon for many years now.

What'd be great about them putting this stuff into the 5D3 would be the marriage of iTR/'3D focus tracking' (what Nikon calls it) with Canon's stellar dual-cross-type technology, and extensive use of cross-type AF points.

Reviews / Re: Tony Northrup - D810 vs. 5D Mk3
« on: September 17, 2014, 12:40:23 AM »
Maybe a D800 would have nailed every shot...I'm a little skeptical of that, given that I still hear pros complaining about Nikon AF, and have read many reviews comparing the 1D X and D4 that clearly indicated Canon AF tracking was superior (although, possibly not your particular close-subject/thin DOF use case.)

Whoa, let's not conflate the 1D X and the 5D3 in this discussion. iTR on the 1D X makes it significantly better than the 5D3 for the type of focus tracking I'm talking about. Furthermore, yes I doubt sports photography stresses the AF system in the manner I'm talking about (remember what I said about DOF of telephoto lenses with large subject distances, and the relative changes in distances to subjects being smaller than for fast wide-angle primes at close subject distances), so there it's possible that the 1D X's diagonal, wider baseline sensors in the center, as well as more cross-type AF points in general, wins.

Also, there was that whole D800 miscalibration fiasco that sunk the collective opinion of Nikon's AF. And I wonder how much of that persists across other cameras - the factories have to individually calibrate every AF point on the sensor! Who does that better? Who knows? I know there are at least a couple of AF points in my 61 point 5D3 sensor that are out of whack compared to the AF points right around it... indicating a miscalibrated point (and not a general skew). This systems are incredibly complex, so I'm not surprised there are a variety of opinions out there.

Also, someone said earlier how Canon's presence is much more significant at the Olympics. That has changed over the years though...

... and again, I'm not saying one system is better than the other for sports. I am not at all qualified to comment on that, as I haven't tested either system for sports. Actually, my feeling is that you don't strictly need subject recognition and tracking for sports photography, since a lot of the action is happening amongst subjects of similar distances from the camera. So, here, other things might matter more.

I'm only commenting on the type of tracking I've explained previously (and for the sake of my sanity, don't feel like repeating again here!).

Reviews / Re: Tony Northrup - D810 vs. 5D Mk3
« on: September 17, 2014, 12:20:14 AM »
Now, you claim that Canon cameras cannot track in the "Z" axis (which I can only assume means within the depth of the scene, towards or away from the photographer), or track in Z while also tracking in X/Y (vertically and horizontally within the frame).

No no no I don't claim that at all. I would never say the 5D3 isn't good at tracking in the Z-axis; in fact, it's phenomenal at it. You got my statement priorities completely backwards in your statement. I'm talking about the 5D3's ability to automatically move the AF point in the X-Y planes to stick with your initial subject as you recompose or the subject moves quickly & erratically in the X, Y, and Z planes.

I'm just going to nibble your post down to this one part, as I think this point is the clincher. So, first, some clarification is needed. When you do this focus and recompose thing...are you using all of the AF points...or are you in a single-point selection mode? If it is the former...then Canon cameras can do this...maybe not as well, but they can.

If you are doing the latter...using the single center point say, focusing on a subject, then recomposing and the Nikon AF system is then able to maintain the lock using OTHER AF points...then yes. You are correct, Canon cameras DO NOT do that. That is how Sony's new AF system works. I didn't quite get it at first when I first saw some videos explaining what Sony's AF was doing...but once I experimented with the 5D III and couldn't get it to do the same thing, I realized what was "new" about Sony's AF. I think that is a kick-ass feature...and I thought it was only a Sony thing. It would be interesting to me if Nikon has had that for a long time...but I would still like confirmation that that is indeed what your talking about.

jrista: Now please go try it on a Nikon D810, D4s, or D750 or what have you, and you'll be blown away by how 'kick-ass' it is on the Nikon's even without a high-resolution image sensor to do what Sony's doing.

We've essentially reached an impasse where you're not going to understand me any further until you just go and try it.

Now, while you may find Sony's AF 'kick-ass' in this manner (and it really is, especially coming over from Canon), in practice, it's not actually as good as Nikon. The A77 II can't keep up as quickly and accurately as the D810 can. So if you were impressed with the Sony... you're in for a pleasant surprise when you try Nikon's 3D tracking.

If I were to rate this sort of '3D tracking' ability, it'd go something like this:

Nikon D810/D750/D4 > Sony A77 II > Canon 1D X >> Canon 5D Mark III

Since I've tested all of these systems, perhaps you can get some idea of why, in my mind, the 5D Mark III lags so far behind compared to the 3 systems above it in my comparison above that I cannot use any positive descriptor when talking about it.

And - much like you - I want the best of both worlds. So I either want Canon to catch up to Nikon in this regard (b/c it still loses subjects more easily than Nikon and/or Sonly A77 II), or for Nikon to adopt some of Canon's significant benefits: more cross-type AF points, wider baseline sensors, and diagonal sensors, to name a few. So, if the inclusion of the metering sensor* in the 7D II is at all indicative of Canon's intentions to start putting these metering sensors in all their cameras (as Nikon has done for quite some time now), then that's *incredibly* exciting to me. B/c I might actually put up with Canon's sub-par image sensor (in terms of Raw DR) if the 5D Mark III replacement had all cross-type points, those dual cross-type center points, EV -3 focusing, along with a 150,000-pixel RGB metering sensor + iTR. As long as their iTR algorithms caught up to Nikon's 3D focus tracking algorithms, anyway. B/c as much as I love Nikon's huge DR for landscapes, and programmable Auto ISO for more intelligent fast-paced shooting, and EC in M mode with Auto ISO, for that matter, it's focus that remains the largest reason for me having to throw away shots (although, I experienced a huge increase in keepers stepping up from the 5D2 to the 5D3; I just wished I'd gotten either the 1D X or the D800 instead back then... but one was too heavy and the other was plagued by AF sensor miscalibration issues and also didn't really fit in my hand with its poorly designed grip). And therefore I applaud Canon for their focus on focus, if you'll excuse my pun. The 7D Mark II's AF sensor, inclusion of iTR, and dual-pixel AF all indicate Canon cares about AF. And that is, simply put: awesome. Because it's the biggest differentiator between mirrorless ILCs and DSLRs today. 

I'm not saying all this matters for every type of photography. I'm just saying it can open up huge doors for certain types of photography. And can even idiot-proof a DSLR once you consider the impact of proper face detection & tracking with a traditional PDAF AF system (which, again, up until the release of the 7D II, only the 1D X had in the Canon line). Or, at the very least, make it easier for pros to focus on more important things, like lighting, composition, capturing the decisive moment, etc. Of course, I won't use face-detection AF for shallow DOF photography b/c you need to nail the eye -- and I'm not yet convinced that Nikon's 3D tracking and/or Canon's iTR are intelligent enough to focus on the eye of the face after detecting the face using the metering sensor.

*Though, I must say, I can't understand why they'd leave out spot-metering linked to the AF point, as it should be easy now that they've got that high-resolution metering sensor in there...

Reviews / Re: Tony Northrup - D810 vs. 5D Mk3
« on: September 17, 2014, 12:07:40 AM »
Many thanks for taking your time with this, being in the process of choosing a couple of extra bodies at the moment, this cleared a couple of misconceptions i had, so thanks once again.

You're welcome, and thanks for taking the time to say this.

My 6D can do what the sample video show, only not so good when the subject too far from centre. I not sure what wrong with the 5D3.
In the 6D vs D600 video, 6D show it was bad when the subject move from far to near.

I didn't say the 5D3 can't do it, I said it can't do it anywhere near as well as a 1D X with iTR, or any modern Nikon with either a 2,016 or 91k-pixel RGB metering sensor (D7000/7100/5300/5200, D800/810, D4/s, D750, etc.).

And with the 6D's paltry 9 AF points... let's not even go there. The chances of there being an AF point where I actually want the focal point of my subject is vanishingly small.

Are you saying you can slap on a fast prime, focus dead center, and then rotate ("recompose" generally involves much more rotation than translation, obviously) the camera about its own axis so the initial subject as seen by the AF unit goes from one side of the frame to the other (or at least from the borders of the PDAF sensors) and significantly out of the DOF and it will track it?

If so, that's cool and I do not believe my 5D3 could do such.

LOL, thank you for writing this :) And, yes, that's exactly what I'm saying. Again, just watch this video:

It's literally that good, and even better on the DSLRs with the 91k-pixel RGB sensor.

Importantly, it can still track that well as you're changing distance to the subject, which is exactly where the 5D3 will get confused. That is, the 5D3 will be much more prone to losing the initial subject once you convolute 2D X-Y movement across the frame with distance changes as well. Unless there's only one or two subjects vastly separated from the background moving forward or backward with not too erratic shifts within a small timeframe in the depth/distance axis.

And this should come as no surprise if you follow my thought experiment in my last post in the ** footnote. In fact, once you understand just how the 5D Mark III AF tracking works (by looking at subject distances across all AF points, but never doing any subject/scene analysis to actually understand what your subject is), you'll be able to predict when/where it'll be good, and where a dedicated color/image sensor will be much better.

Reviews / Re: Tony Northrup - D810 vs. 5D Mk3
« on: September 16, 2014, 11:51:01 PM »
I think your mesuabating to the point where your blaming gear for your shortcomings. Even if the Nikon is better at tracking, of what good is it if real photographers like jrista or the myriad of others here are already getting the results with the superb 61pt system in the situations you described. That just shows you don't know how to get the frames you want.

No, it means that a system without scene recognition for AF doesn't allow me to get the shots I want for some of my photography. Are you suggesting that 'real photographers like jrista or the myriad of others' represent the entire sample pool of photographers & potential types of photography in the entire world? It really takes some perverse logic to think you understand the needs of every photographer out there so well that you can say 'even if Nikon's AF tracking is better... it doesn't matter.'

Doesn't matter? So the entire focus problem has been completely solved in the industry? Everyone is able to get 100% hit-rate with any prime at f/1.4 under any circumstance?

And - measurebating? Really there's no winning with you. When we're talking about numbers and equations, we're measurebating. When we're talking about real world experience with fast primes and ability of the camera to keep up as a subject moves around erratically, we're still measurebating! I'm saying that a scene recognition system is so good at tracking a subject accurately in 3 dimensions that after you've used it, you just cannot say the 5D III is good at it. Yes it can do it, but it gets confused very easily. And if you just took a minute to think about how the 5DIII is doing it, vs. how the 1D X and 7D II and Nikons are doing it, you wouldn't be at all surprised either. Go back to my thought experiment I posed to jrista in one of my responses, and see if you can understand why an image sensor is much better at tracking than the algorithm the 5D III uses. For your convenience, I've posted it at the end of this post.**

Btw, here's the new Samsung NX1 doing it, with PDAF sensors all over the sensor:

But I suppose that's useless, since the 5DIII is obviously good enough for jrista & a myriad others and therefore every photographer in the entire world.

By the way, did you know that most current Nikon DSLR can focus on faces outside of Live View* (using traditional PDAF and OVF viewing)? Down to the D5200, I believe. And any Sony SLT, of course? Meanwhile, up until the release of the 7D II, only the 1D X could. Because it was the only camera with a separate color sensor for scene analysis. If your face happened to be the closest subject, sure a 5D III would focus on it in 'auto AF area' mode. Have a flower, or any other subject in front of the face, and the 5DIII focuses on that instead. Switch to a 1D X with iTR, and it'll focus on the closest (or biggest, I'm not sure) face, and track it as well. Not a big deal for me, but great when I hand off the camera to a family member to take a photo.

So now with the introduction of the 7D Mark II, do you think the inclusion of iTR with the RGB metering sensor is just a bunch of marketing hype? A 'me too' feature? Or do you think perhaps Canon is including it now b/c its actually of some utility?

Because, at the crux of it, you're essentially arguing that iTR is completely useless. And I completely, radically disagree.

Now if you want to complain about something legitimate, then point out the lack of AF point metering because that really does suck at times but saying the 5D3s AF is bad at tracking means that you didn't RTFM.

I did point that out. Almost every Nikon camera, down to the D5200, has spot-metering linked to the AF point. Because that's yet another thing the RGB metering sensor enables.

Just b/c you don't think the metering sensor 'seeing the scene' and providing face-detection & subject tracking isn't useful, doesn't mean it's not, or that I didn't RTFM.

What's your point of repeating the phrase 'RTFM' other than to incite me? Do you think that phrase is conducive to intelligent discussion? 

and yes, the nikkor G primes still AF like a slug and that alone shifts AF speed to canons for weddings. (And I've shot a lot of them only with primes.)

Demonstrably false, and yet another blanket, unsubstantiatad statement. The Nikkor 24/1.4 keeps up no better than the 24/1.4 on a 5DIII in terms of speed of Z-axis tracking in my limited testing of them side by side. Perhaps a very controlled scientific study might demonstrate otherwise, but like a slug? I don't think so.

The Sigma 35mm f/1.4 is even better (and meanwhile retains full 3D focus tracking ability, since it reports distance information).

And why don't we talk about 85mm primes now, a workhorse for weddings? The Canon 85/1.2 is so slow to focus that I've missed many shots, finally opting to go with a 85/1.8, only to find its focus precision was quite poor. The Nikkor 85mm primes, OTOH, are great in terms of focus speed. Why would you leave that out of your 'Canon primes are faster for weddings' blanket statement?

Not to mention the 85mm f/1.2's enormous CA on the sides such that it doesn't sharpen up until somewhere between f/2.8 and f/4:

Here's the Canon 85/1.2 vs Nikkor primes wide open:

Here's the 85/1.2 at f/2.8, where it's still not as sharp/uniform as the Nikon 85 primes at f/2 and f/1.8, respectively.

If you want to talk about advantages of the 5D Mark III focus system, talk about its cross-type points all over the frame, and its wider baseline diagonal points in the center of the frame.

*But to be fair, it's doubtful the D5200-D7100, with their 2,016-pixel RGB sensors, do it anywhere near as well the more pro-level bodies with their 91,000-pixel sensors. The higher the resolution of the metering sensor, the better. Then again, I was surprised even the 2,016-pixel metering sensor in the D7000 could aid subject tracking well, but it does a reasonably good job. Certainly much better than my 5D Mark III.

**Here's an example of how the 5D Mark III focus system works. Let's say the center point of the AF system detects a subject 10ft away, then you recompose, then the camera notices a subject 10ft away is now over the left-most AF point, and meanwhile there's now nothing at 10ft away at the center point. Therefore, the camera decides your subject has moved (or you've recomposed such that the subject is now at) the left-most AF point. But what if your subject moved to 9ft away during this time as well? Well, with some clever algorithms you could analyze all the focus points and see if there was some progression of a subject like this (I've assigned letters to specific focus points for ease of discussion):

  • Subject in center point (C) 10ft away
  • Center point C no longer detects anything at 10ft, but the point just to its right (D) has a subject at 9.8ft
  • Point D no longer detects a subject at 9.8ft, but the point to its right (E) detects a subject at 9.5ft.
  • Point E no longer detects a subject at 9.5ft, but a point 6 points to the left (F) now detects a subject at 9.2ft.

... and so on and so forth.

Are you starting to see how incredibly complex this can get, and how prone to failure this might be if the subject is moving like this in 3-axes and/or the movement is convoluted with you recomposing? Or another subject entering the frame at a similar depth?

Are you starting to see how using an image sensor (Sony SLT, or all mirrorless ILCs really), or a color sensor with some finite resolution to recognize color patterns (enough to detect a face, which we know RGB sensors can do given their face-detection ability) that communicates with the PDAF sensor might have the potential to perform significantly better?

Incidentally, many types of bird photography are unlikely to stress this type of system much, since you typically have one subject at a very distinctly different depth from everything else (the background or sky). And when the bird moves, its typically going to move along the depth-axis with measurable acceleration or deceleration - which allows the predictive AF to work quite well (and I've already said Canon does this very well). Also, keep in mind the DOF for extreme telephoto lenses at large subject distances. For example, 300mm at f/4 for a subject 30m away has a DOF of 2.3m, giving the AF system more room for error compared to a subject 1m away shot with a 35/1.4 where the DOF is 6.4cm (and where it's very, very easy for the subject to fall out of that DOF or for the photographer to move more than 6cm).

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