PDA

View Full Version : Convergence vs Divergence



swifty
27-10-2013, 1:15pm
Interesting article on LL:
http://www.luminous-landscape.com/essays/an_appeal_for_divergence_and_simplicity.shtml

What's your take on convergence vs divergence with respect to photography and cameras?

ricktas
27-10-2013, 1:52pm
I thought it was an interesting article, with some good points. Till he got to the aperture/ISO/Shutter speed issue. I really do not see the issue with pushing one button and then dialing in the ISO, or using the back and front 'wheels' to set aperture and shutter speed. In fact it is quite intuitive and easy to do. He lost me at that point.

Now onto convergence/divergence. I have a D800, I use it to shoot still photographs. It can do video, but to be honest I have not once 'played' with that, or accidentally turned it on. The D800 is a very good bit of kit and to argue that a still photographer is somehow missing out on something cause the device is converged doesn't gel with me at all.

My car came with a cigarette lighter, I am not going to ever use it, but I am also not going to demand that the manufacturer stop including it.

I think he is on a rocking horse and expects it to win the Melbourne Cup.... he needs to get off and go take some photos, and ENJOY his photography.

ameerat42
27-10-2013, 2:40pm
Must admit, I skipped though it earlier. Had another read and...

and...

...and...

Am(..and...).

PS: Oh, that was it: I have no views. Not saying you shouldn't have posted it, Swifty. I just think the world wouldn't have budged a bit either way. Seems he just wanted to write something.:rolleyes:

swifty
27-10-2013, 3:25pm
Am: lol.. Yea I posted it cos I thought it'd be an interesting point for discussion. I agree with some principles he raised but like Rick, I think the article descends into a rant with personal gripes for particular ways certain manufacturers do things.
I also personally find press + turn dial very intuitive but each to their own.

My personal views are that convergence is good, and even necessary in the consumer end of photography however the higher and more specialized a tool becomes, the more it needs to diverge and be very focused at what it's designed to do.
To use your motor vehicle analogy Rick, up to a certain point a car needs to do and include a little bit of everything eg. Mercedes Benz S-classes, and do it very well. It's very high performance and has a lot of bells and whistles. A D800 if you will.
Once you get to track edition of certain cars, then manufacturers start removing features deemed unnecessary for their specialized needs.

arthurking83
27-10-2013, 3:45pm
LOL!
I agree with the current analysis of his writing .. it's all a bit of a useless rant and it seems to me he's bought the wrong gear.

In about 5000 exposures with the D800 so far, I've never ever found that having a video feature has limited my ability to capture any image that I've tried to get right in one go.

In fact, I'm convinced that it may be due to video capability that I'm finding it it easier to get some otherwise harder to get images. Primarily, but not exclusively, high magnification shots.

You want simple, get a box brownie. :rolleyes:

While this fellow may think a lot of other people do this, or use that, the feeling I get is that he's comments are simply jaded by the fact that he's not into it.

His comment about some people using DSLRs for video and then using large innocuous contraptions to handle them properly ... yeah? .. and?
I want to know who these people are .. that don't like using these bulky contraptions? .. I guess they're just better off using a high end Red system or Canon XL/XF system .. :confused:

One thing I certainly know is that he's not representing my wants in any manner at all. I want video capability, and I want it in a high quality still camera too .. saves me a hell of a lot of money, and gives me a massive amount of creative freedom in having this option.
I'm yet to use it(time) .. but it's there when I want it.

It seems to me he knows too much ... and just happened to need to share this knowledge :rolleyes:

ricktas
27-10-2013, 3:50pm
he also seems to have forgotten that with film, the ISO you used was the one rated on the film. Not easy to just dial up another ISO after shot 6 of a 24 exposure film. I think being able to push and dial in a new ISO after each shot is not really that hard to do.

arthurking83
27-10-2013, 5:48pm
So he want's superfluous dials and buttons replaced with superfluous dials and buttons!

makes sense!

Just had a read of his ALPA 12FPS write up too and it basically sums him up perfectly .. he's only interested in a slow and deliberate workflow(judging by his waxing lyrically of the 'main control dial' on that device).

what if you want to change shutter and aperture in the same direction(ie. not maintaining a constant exposure) which is easily done on most DSLRs .. and he wants us to think that this ALPA is simplicity at it's best! :confused:


Seriously .. if I had a need for constantly evolving ISO needs, I leave it to auto(autoISO) .. which is usually about as good as it gets. Let the camera choose the best option based on my metered requirements.

His comparison between the user friendliness of an iPhone compared to a modern DSLR is simply laughable! With that one he just sounds amateurish to say the least.

iPhone simple .. DSLR complicated .. errr .. if he can't see the need for such a varied setup for a specific need, he really shouldn't be writing photography articles on LL!


he also seems to have forgotten that with film, the ISO you used was the one rated on the film. Not easy to just dial up another ISO after shot 6 of a 24 exposure film. I think being able to push and dial in a new ISO after each shot is not really that hard to do.

if you read the ALPA review Rick .. he prefers this system of control(quoted below) over the convoluted DSLRs system of button push and dial turn(for ISO) ....


To me, one of the most brilliant ideas in the design of the FPS is the knurled dial on the top right. Let's assume that you mount a DSLR lens on the FPS. Rotate the dial and it changes the shutter speed. Now, press the dial down. It's function has changed; if you now rotate the dial the lens aperture changes. Press it one more time and when you rotate it both, aperture and shutter speed change in synchrony preserving the same exposure. Press it a third time and you are back to changing the shutter speed when you rotate it.
His description of the main function dial on the ALPA

So he prefers this workflow method of ISO control: a dial push .... a dial push .... a dial push.... and then turn the dial ... over what amounts to a simple button push and simultaneous dial rotation(max 1 sec .. generally 0.5sec) on many DSLRs.
That'd drive me bonkers, and I'd never get a camera body that works in that manner




I'm assuming he's one of these world's foremost photographer(of some type) shooting major sporting events, photojournalism or wildlife in some of the most inhospitable places on Earth ... with his iPhone! :D


... <shakeshead> ....

swifty
27-10-2013, 6:58pm
AK: I hadn't delved into his other articles of the cameras he referenced. But from your excerpt it does seem comical he would complain about the simple push and rotate on DSLRs when he showers praise on, you guessed it, a push and rotate (even if its on the same dial).

The article was just a reference really. I may have inadvertently placed too much focus on a singular opinion whereas I was more interested in the general topic of convergence and divergence.

Convergence doesn't just mean video of course. Other technology are creeping into the photographic camera too.
How many would cringe if a dedicated social media button appeared on a D800 class camera. Kinda like the 'direct print' button joke that was around years ago.

ricktas
27-10-2013, 7:23pm
How many would cringe if a dedicated social media button appeared on a D800 class camera.

Not as silly as it sounds. I am a member of an Aurora watch group here in Tas, and when an Aurora alert goes out, the group ends up with heaps of phone photos of Digital SLR screens showing their captures, so that others can decide to head out to shoot the Aurora or not. I can see a use for the button you speak of. Though I personally would not use it much. A better option would be bluetooth so that said photos could be easily transferred to tablet on location, edited and the uploaded to social media.

swifty
27-10-2013, 9:01pm
Well.. true the button could be immensely useful for some. I'm sure there's a guy somewhere saying 'but I use the direct print button' too haha.
But a lot of people will still cringe though.

ameerat42
27-10-2013, 9:08pm
(I still reckon buttons a best on shirts, and the like.)

arthurking83
28-10-2013, 8:19am
If buttons are functional, then the more the merrier.
I like the idea of a button and a simultaneous dial rotation, which then gives many combinations of settings adjustments.

I have no fear of convergence in upper end cameras. Of course there's a limit on what sort of convergence is useful.

That is, I don't need to view/edit/create EXCEL spreadsheets on my camera, as I have both my phone and PC to do that .. and if I had no phone, I'd still not want it on my camera .. I'd just get a PDA for it or something.
Same with emails, or games or whatever ....

Video is complimentary to stills really, so for those two media types it makes sense to converge them into a single media device.
Afterall, I'm sure there are many PJs remaining out there(if there are any PJs left out there) that actually use those features for serious purposes.
I have no problem if they add 4K video to a D800 replacement either instead of some other stills feature tweak.

The complimentary nature of converged features seems to improve the breed.

Features such as wifi in cameras isn't a bad thing, as many have shown .. as long as it's implemented well, and it seems that there are many out there that use it to good effect.
Just because wifi can be used to 'upload to facebook' or share instantly on your connected fridge or whatever other silly use that people can come up with .. doesn't mean it's not a useful convergence feature.
Remotely controlling the camera, remote feeding from camera to device .. etc ... very handy as many people have pointed out over the years that it's been creeping into cameras.


On the topic of convergence, I prefer Thom Hogans outlook. Even tho he doesn't refer to convergence directly, he refers to it indirectly with his commentary on CPM(communicating, programmable, modular) .. which by default implies convergence .. even more convergence than we've already seen.
A programmable camera by extension will be able to do many more things than they can do now .. even those EXCEL spreadsheets that I don't really want! :p

Like I said before(and for the purpose of opening up the thread to more commentary) I like convergence if it's intelligently implemented. I like the idea of programmable cameras, although the OS will need to be open source.
Allows the programmer a much more free hand to program their small app to do things that otherwise may be difficult to do.

Imagine proper HDR/stitching/etc in camera on a set of raw files .. where the raw files are kept separately to the HDR/stitch/etc.
Imagine more flexibility for time lapses, or exposure delay modes .. or whatever.
We know the camera can do a lot of this stuff, it's just that the manufacturers can't be bothered to tweak the firmware in this manner.

I still think(as of this moment) that Android is a good OS for operating a camera .. as long as it was specifically setup for camera operation, and not connecting to facebook/google/weather/etc.

I like using the Galaxy Camera for fun stuff. It's slow as hell compared to a DSLR, but no slower than any other P&S(which is what it is).
But a major advance over any P&S I've experienced. Terrible lens tho, and IQ suffers for it .. so it'd be nice to see Android implemented in a higher quality camera.
(I know that Samsnung have Android working on an interchangeable lens camera somewhere else in their lineup(NX300 or something) but I have no interest in a new camera system ATM.

swifty
28-10-2013, 4:14pm
Well thought out logical opinion AK. I agree on many points.

I think it boils down to this:


Of course there's a limit on what sort of convergence is useful.

Its very subjective. What's useful to one person may very well be a nuisance to another. In a worse case scenario it impedes the photographer from doing what they normally do.

Another argument of course is the opportunity cost of developing alternative features with little benefits to the original stills camera. Conversely R&D in other areas could also lead to improvements in still function. Things like global shutters and on-sensor PDAF, improved CDAF for example.
Then there's the actual monetary cost of R&D. There's no free lunch. However even if the said feature doesn't get included in the final product, the R&D cost probably still gets incurred so you could argue that it essentially is a free feature so you may as well include it. For hardware style features there will be the additional components/assembly costs though.

It might be a generational thing but over at the LL forums, you get a lot more responses whole heartedly agreeing with the above article.

I'm quite familiar with Thom Hogan's writing and his CPM concept. I don't think its entirely a convergence issue though but more a user's ability to maximise and customise existing hardware thing. CPM can be both convergent and divergent. If the software was programmable you could turn off all functions you find useless and have a very basic camera with a very clutter free menu. Or you could automate a lot of functions that would be nuisance to repeat each time.
On the hardware side, what else should/shouldn't be added to the humble camera is also very subjective. Wifi, GPS, Bluetooth, accelerometer, projector, etc. The list goes on and any photographer could argue one or more of those are useful to them.

I guess I feel the camera is at risk of becoming overly complicated. Eg. I can't say I agree that the more buttons/dials the merrier. I'd rather the least number of buttons and dials that I can do everything I want but again, that is extremely subjective. How many does one need?

Anyways.. I haven't really formed a solid opinion on the subject, hence why I thought it'd be interesting to hear everyone's views. Yours too, Am ;) I personally like buttons of the cocoa variety even better.
Thanks to those who've participated. Love to hear more sides to the discussion, not just from experienced photographers but anyone who's willing to share.
Cheers

I @ M
28-10-2013, 4:50pm
Wow, talk about someone struggling to keep up with technology!!! I thought that I was bad but he takes the cake.

My message to him would be, learn how to work around the imperfections of any piece of gear or go out and produce your own perfect item.

I kinda lost interest when I read this bit ---

"Why does Nikon have two separate memory banks and why can one not lock the profile memory settings? One minor change (such as exposure compensation) for a single image and without warning the camera changes your profile for all subsequent shots. Ridiculous!"

---- If he hasn't figured out how to do that then he hasn't spent much time researching how the camera operates. Or does he want a truly automated experience to his photography? :rolleyes:


Perhaps his last word in that quoted part sums up his thought process.

fillum
28-10-2013, 8:23pm
On the bench in my kitchen is a toaster. It's a cheap one from K-Mart or somesuch. We've had it a fair while and I use it most days. On the end are three buttons. The middle button ejects the toast. I don't know what the other buttons do. I think one might be video, and the other might be a direct connection to facebook. But I don't know. I don't use them.



(I still reckon buttons a best on shirts, and the like.)Re shirts, I do like the new-fangled ones with the converged cuffs and collars...




:D
Cheers.

Tommo1965
28-10-2013, 11:33pm
Im with the writer..cameras are way to hard to navigate and master..I would much prefer a digital SLR that looks like and can be controlled like my old minolta X700 http://www.jafaphotography.com/images/eq/x700a.jpg...yes it did have program modes and a green P button for those that needed it...I also perfered that the Iris control was on the lenses rather than a button on the body....

I know the new bodies have controls that do the same thing...but for me I prefer the old way and look of a more simple experience

I sometimes find ( read quite often) that the technology gets in the road of taking pictures ..also about 95% of what my D800 does I never use


of course this IMO and YMMV...

Tannin
29-10-2013, 1:35am
Yep, good link, and the writer speaks for many, many photographers. The worst part, however, isn't the (useless) extra functions being crammed into still cameras so that they can be second-rate video cameras, it is the massive divergence of design and manufacturing effort away from the development of cameras and into the development of hybrid movie things. I haven't bought any new camera kit for close to a couple of years now, and if you know me, that's really saying something serious. Why not? Because, frankly, the camera manufacturers just ain't putting any real effort into developing product real photographers want to buy - it's all hybrid moviecam stuff which is basically useless to me, or to anyone else like me who loves still photography and isn't interested in movies.

Just in the Canon world - make your own comparisons in other brands - where is the replacement for the ancient 7D? Where is the replacement for the really ancient 1Ds III? (And no, the half-baked 1D X isn't it.) Why are nearly all the new lenses designed for video? (All those STM things are fine as far as they go, but they weren't created for photographers and add little or nothing to what was already available.) Where are the lenses Canon photographers really want and would pay good money for, such as an EF-S 60 Macro IS to match the 100L Macro? The way, way overdue 100-400 replacement? The 400/5/6 IS? A decent zoom fisheye instead of the brain-dead current design? A half-modern 50/1.4 USM - can you believe that Canon, of all companies, doesn't have a good, middle-of-the-road standard lens, only ultra-cheap (1.8), ultra-expensive (1.2) and the ancient low-tech 1.4? Where are all therse things? Why, they are in never=-never land 'coz all the R&D dollars are going into video.

swifty
29-10-2013, 1:37pm
Along the same vein but not exactly a convergence issue, is what we're doing with our images and how we get it there.
There's definitely technology creep going on in this space and here's an interesting article of another author's view on the subject.
http://www.gearophile.com/newsviews/the-future-of-cameras.html

AK83 already touched on this issue in his earlier post.

For clarity sake, the first article on LL is by Mark Dubovoy and the article I just referenced is on gearophile by Thom Hogan.

arthurking83
29-10-2013, 10:33pm
......

I know the new bodies have controls that do the same thing...but for me I prefer the old way and look of a more simple experience

...

I'm not 100% certain Tommo, but I think you can turn some of those widgets/buttons/levers off if they annoy you.

In a year of D800ing, I've found only one ergonomic issue with the design layout of the camera.
Funnily and in contradiction to my earlier replies (on how video didn't kill the photographers tool) .. this ergonomic flaw is partially related to the video feature.
On the D300, changing modes from M to A was easy as pie with my right hand and camera at eye level. The Mode button fell perfectly to finger(index) distance, where a quick rotation of the thumb allowed a quick seamless change.
D800 now has a red dotted record button where my index finger falls too, and the new location of the mode button is a contortionists dream .. either that or my crucified index finger is not on it's last legs(shot a nail through this finger a few years back!)

Not a big deal, but a very slight workflow change is required going from D300 to D800.

Other than that, I'm pretty much 99.9% content with the workings of the D800's accessibility controls.

Live view is a button so heavily used nowadays by my, I think the silk screened markings on it will be the first to fade to black(so to speak).
On the D300, this honour fell to the AF-On button .. which turned black after only a year or so(so heavily used was it!)

Being such a massive fan of Liveview with the D300 way back when allowing so much more control .... but it's implementation was about as retarded and backward as it gets!

if better video capability gives me better liveview ability too(in any respect) then bring on more convergence!


..... 'coz all the R&D dollars are going into video.

I doubt much money went into video capability over the course that it's been a feature on DSLRs. I think it was inevitable anyhow.

In fact I believe that so little R&D money has gone into adding video on DSLRs, I remember a post way back by William on how a simple firmware hack by a thirdparty had turned a previously non video DSLR into one that is a video capable DSLR! (http://www.ausphotography.net.au/forum/showthread.php?114413-Converted-the-50D-to-Video-Cam&highlight=50D+magic+lantern+video)

Really how much R&D would it cost to add a simple feature for the mother company .. when a thirdparty that doesn't have access to the original source code can do it for free?

But, in terms of improving video ability, yeah .. they'd have spent heaps of R&D dollars on keeping the sensor from overheating and producing a cleaner image ... just as it should for hours long exposures and less noisy still images.

I don't know much about STM lens(es) specifically, but if they are what I think they are, then their design and benefits are yet to be full seen on DSLRs.

My understanding of the old type DSLR lenses, is that they're optimised to focus speedily when using CDAF as was the case for DSLRs for an eternity.
Their inherent design is such that they need to be quick to 'hunt' to acquire focus. So for CDAF cameras, this makes sense as in reality the lens is actually hunting to achieve focus so that the camera/lens combo focuses quickly.
PDAF is different tho. The design is such that the AF sensor actually knows which way to turn the lens, so that AF is not done by hunting(the lens), it's achieve with a decisive and direct control communicating to the lens which way to turn and by exactly how much.

non PDAF optimised lenses(ie. any standard af lens type since day one in AF lens history) don't work well in PDAF mode compared to PDAF optimised lenses.

My (admittedly very small) understanding of the STM lens in Canon's line up is that it's PDAF optimised .. hence why it's fast to focus on the 70D.

With all the complexity and annoyances of inaccuracy in CDAF(did someone say D800! :p) ... long before EVF replace OVF, PDAF will replace CDAF in DSLRs for many reasons.

I have no idea on how easy it would be for manufacturers to convert current lens types into PDAF optimised versions ..... if at all possible to do.

if this is indeed the case, I'm hoping that Nikon offer some sort of conversion process(like they did for non Ai to Ai) ... don't want to be stuck with a slow focusing lens that won't work well on some future camera that I'll end up with.

I have to admit tho, my only knowledge of the STM lens from Canon was the comparison that DPR did between a 70D+STM lens vs a Sony camera.

The point is: that this videocentric feature(or requirement) will eventually see benefits in that af modules and lenses will not 'hunt for focus' any more and will know exactly which way to focus and by exactly how much.

Another benefit to stills capture due to the inclusion of video in still cameras!

I can see how that the inclusion of video specific controls have been creeping into cameras more and more .. and for that, I'd also like to see less of them, or more importantly customisability of these buttons .. in fact not only these buttons but all buttons. Every button on the camera should be made to operate one way for stills, and when you switch to video mode, they do whatever they're programmed to do.

This makes the most sense as it's not only rare to capture video and still(well not extracted stills!) concurrently .. but it's downright impossible .. you shoot either video or hi res stills. So it makes sense to have the buttons customised in various ways to suit the mode you're using.

As for features in DSLRs .. this is what usually separated them from the toys. More features generally meant more performance. So you used an SLR because it gave you some advantage, or that it could be tweaked in many ways(exposure.... or whatever).
I remember way back when the D800 was new, and it caused no end of grief for many with it's misfocusing issues .. and I posted a reply to one thread commenting that it'd be nice if manufacturers gave us not only the almost useless AF-Microadjust .. but one that made more sense, where you can adjust each individual point if wanted(better by PC, but even directly on the camera would have been good).

We know Nikon won't do this until all the other brands have done so first ... so here we go(have a look at some of the advanced micro adjust features on the Olympus OMD E1-M5(stupid camera name BTW!)
If Olympus had a FF camera .. I'd be in! :D
if you can't be bothered to take the time to read up on this camera, it has the ability to micro adjust each focus point independently(or as a whole), and it seems on zoom lenses at either wide or tele focal lengths.


I think that if you're going to bother with a feature on a supposedly high end camera(like an SLR is supposed to be) then either do it properly or not at all. Half arsed implementations don't work well ... and we know that it's not hard to do.

Apart from one or two other areas of DSLR workings(mainly AF point selection), I have no problems with where DSLR functionality is heading.


.. ooops, long post(sorry) :o

Tommo1965
29-10-2013, 11:22pm
I used to like looking at the camera and making judged decision and what exposure setting id do next and then with some thought taking the next frame ..I've had the cameras with input dials since my EOS650/750 days...but the magic of a full manual camera in terms of mechanical input and some thought process is somthing I miss.....the amount of times I've rubbed against the shutter and aperture input dials and inadvertently changed my exposure is many..and without noticing :o

I know you can lock them..but yet another menu item buried..I expect I could set a button for that..but id forget which one it is :rolleyes:

Im not that old that I didnt cut my teeth on the new way of changing exposure ( input dials) as I did...but the magic of that little X700 with a full manual aperture ring and shutter speed dial is something I loved and took some of the best pictures i've ever captured with it .


one thing i've recently discovered on the D800 is the ability to change the ISO with the rear input dial if in AV..of the front if in TV. modes ..thats made life better

Dont get me wrong..i love the d800...but do yearn for a more simple experience ..

video..whats that :D..im still using VHS

ricktas
30-10-2013, 6:07am
Interesting that people seem to think these buttons and dials turned up in reasonable recent years, commenting as though they are a recent and sudden change. Yet here is the top of a Canon T70 which was introduced in 1984 - almost 30 years ago!!! I have one of these. It was the first SLR I bought with my own money..once I started working. Prior to that I was given cameras as presents and gifts (box brownie, kodak 110 instamatic)

http://www.kenrockwell.com/canon/fd/t70/D3S_3028-top.jpg

and before that, the Canon T50 (in 1983)
http://pad3.whstatic.com/images/thumb/7/70/01-T50_back_open_391.JPG/670px-01-T50_back_open_391.JPG

This change has been gradual, not something that has happened overnight, and given us all plenty of time to adjust to it. Sometimes getting out of your comfort zone is good! Just as some do not like Convergence, some appear to not like change as well:D Sometime we spend to much time talking about the gear we use, than using it...anyone want to meet me on DPReview :cool:

Tommo1965
30-10-2013, 9:37am
LOL..yeah I get that about "talking about the gear rather than using it"..Im very guilty of that :o

my X700 was introduced in 1981...but i never bought it then ..I started with a EOS 750..then a week later after buyers remorse ( yes we had that in the eightes too) a EOS 650 which was released in 1987 ..i then traded that in for the x700 as I wanted to even then, De Tech myself ...seem silly now as even the EOS650 was a basic camera by the D800 standard...but i want manual focus lenses etc..( also they were cheaper to Buy)

http://www.mrmartinweb.com/images/camera/slrauto/eos650.jpg


I still have the x700...its a beauty...Ill never shoot with it again.. so I do embrace the new Tech...just wish the interface was a little old-old Tech sometimes

ameerat42
30-10-2013, 1:58pm
(Last time I looked there was close convergence of opinion on the degree of divergence from whatever opinion the article's author was espousing.)

Am(generally in parallel).

swifty
30-10-2013, 2:36pm
I don't know much about STM lens(es) specifically, but if they are what I think they are, then their design and benefits are yet to be full seen on DSLRs.

My understanding of the old type DSLR lenses, is that they're optimised to focus speedily when using CDAF as was the case for DSLRs for an eternity.
Their inherent design is such that they need to be quick to 'hunt' to acquire focus. So for CDAF cameras, this makes sense as in reality the lens is actually hunting to achieve focus so that the camera/lens combo focuses quickly.
PDAF is different tho. The design is such that the AF sensor actually knows which way to turn the lens, so that AF is not done by hunting(the lens), it's achieve with a decisive and direct control communicating to the lens which way to turn and by exactly how much.

non PDAF optimised lenses(ie. any standard af lens type since day one in AF lens history) don't work well in PDAF mode compared to PDAF optimised lenses.

My (admittedly very small) understanding of the STM lens in Canon's line up is that it's PDAF optimised .. hence why it's fast to focus on the 70D.

With all the complexity and annoyances of inaccuracy in CDAF(did someone say D800! :p) ... long before EVF replace OVF, PDAF will replace CDAF in DSLRs for many reasons.

I have no idea on how easy it would be for manufacturers to convert current lens types into PDAF optimised versions ..... if at all possible to do.

if this is indeed the case, I'm hoping that Nikon offer some sort of conversion process(like they did for non Ai to Ai) ... don't want to be stuck with a slow focusing lens that won't work well on some future camera that I'll end up with.

I have to admit tho, my only knowledge of the STM lens from Canon was the comparison that DPR did between a 70D+STM lens vs a Sony camera.

The point is: that this videocentric feature(or requirement) will eventually see benefits in that af modules and lenses will not 'hunt for focus' any more and will know exactly which way to focus and by exactly how much.

Sorry but I'm completely lost in this middle part of your post.
Firstly, aren't DSLR lenses (other than Canon STMs) designed for PDAF, not CDAF?

As you've said in PDAF, the AF system knows in what direction and by how much to focus the lens. This happens in both traditional PDAF and on-sensor PDAF. So all traditional DSLR lenses are designed to make quick jumps and in the right direction according to what the PDAF is telling it to do.

But before the introduction of on-sensor PDAF, the traditional PDAF designed DSLR lenses worked poorly in liveview mode of DSLRs which uses CDAF. Cos in CDAF the AF doesn't know which direction and by how much so it achieves focus by hunting/scanning back and forth and analysing the amount of contrast. The corresponding CDAF lens then needs to have smooth incremental AF motor steps as the CDAF system analyses the image for differences in contrast, which PDAF DSLR lenses weren't very good at doing because their motors are better for quick big jumps.

In traditional DSLRs, there's an alternative optical path for the PDAF sensor (the submirror just behind the main mirror directs light to the PDAF module). So when the mirror was removed in the mirrorless camera designs, the cameras had to rely completely on CDAF which was sensor based. So began a whole generation of new lenses for mirrorless cameras that are more opitmised for CDAF but they faired poorly in C-AF cos every time the subject moved, it didn't know which direction to adjust focus unlike with PDAF. But now virtually every manufacturer has figured out how to add PDAF on the sensor itself so now even traditional DSLR lenses worked better on mirrorless cameras that have on-sensor PDAF cos that's how traditional DSLR lenses were designed to work. Many of the manufacturers have moved to a hybrid design where the PDAF does the large directional AF adjustments and the CDAF takes over for the fine AF adjustments cos its more accurate. The OMD EM1 is an example of this.

CDAF and now on-sensor PDAF aren't inaccurate at all. They are very accurate because they are located on the sensor itself. Rather than a different location with its own optical path as with traditional DSLRs that also meant traditionally the alignment had to be very good. The D800 issue was a misalignment of the PDAF module with the sensor. This is also why micro-adjustments are very useful and necessary for the traditional PDAFs.
With on-sensor PDAFs, the micro-adjustments are necessary only for tolerances in the lens but the AF sensors are located on-sensor and shouldn't have any alignment issues.

STM lenses are designed with different motors for smooth incremental steps in focus change. I haven't read anywhere that its got any PDAF optimisation, rather its designed really to work well with CDAF. The first STM lenses appeared mid last year and the first on-sensor PDAF Canon camera (70D) only appeared this year. It is very much a video-centric lens design with silent focusing and smooth incremental AF changes as well as smooth aperture iris control (as opposed to stepped).

arthurking83
30-10-2013, 7:23pm
LOL yeah sorry Swifty .. late night post, arduous working hours .. stressed eyeballs, and good dose of goofed up brainfade by the dummy banging on the keyboard!! :D ..

I mixed up CDAF and PDAF in my reply there.

swifty
31-10-2013, 6:14pm
LOL yeah sorry Swifty .. late night post, arduous working hours .. stressed eyeballs, and good dose of goofed up brainfade by the dummy banging on the keyboard!! :D ..

I mixed up CDAF and PDAF in my reply there.

No worries, no biggie.