Phase detection or not phase detection….that’s the question! Mirrorless cameras are currently do lag behind most DSLR cameras in terms of autofocus speed. That’s why Sony is developing a sensor for NEX cameras that has built-in phase detection capabilities. I found (again) a new patent that describes the technology (Click here to see the publication at freepatentsonline). Fuji is already using it on the [shoplink 6047 ebay]Finepix Z800EXR (Click here to see that camera)[/shoplink]! See the Fuji camera specs at [shopcountry 6047]. There is also a nice article on Dpreview (Click here) that describes the Fuji technology.
But I don’t know if such a sensor will be ever implemented in NEX cameras. Rumors are saying that Olympus next PEN cameras will have an extremely fast and accurate autotofocus and catch up with DSLR cameras in terms of af speed. So maybe Sony is wasting time with it?
39 Responses
It’s about time the mirror was gone.
I still think phase detection is the way to go,as its fast with dumb lenses,while oly’s new fast cd-af needs new brainy lenses to be fast..also phase detection on chips could give you much better focus control with manual lenses which are great on the nex.
Whats that “one major rumor” that you mentioned in a previous post? 🙂
It’s coming next week Monday or Tuesday. It’s a BIG “rumor”. I will write a post when I know when I can publish that. It’s a very “delicate” work that I have to do. Anyway, it’s one of those posts you will remind for a long time 😉
nice! also cant wait for the a77.. its going to be a big relief to finally know what the a77 will deliver
Alpha A99 or Nex-9 ? 🙂
I will probably post the rumor on “Monday”. I am asking my other source if what I got is correct…but I am sure it is! It’s A77 + surprise picture 🙂
Really?
Hmmm interesting…
can you magically make it a ff nex? 🙂
No 🙁
The new, fast Olympus AF is more a feature of lens technology than one in the camera. It is not backwards compatible to any existing mft lens. The charm of an on sensor phase detect autofocus is, that it will work with classic lenses and generally makes the lens designs simpler
Andre, all of us here are hoping it’s a FF prototype picture which comes along the A77 pictures you must for sure have in the hands by this time.. 😉
No FF NEX or SLT. At least not yet. But I am working on FF rumors too…don’t worry!
well..i hope there would be “A” rumor about ff…another hope of mine that sony would actually release a nomral 28-35mm f2(or faster) pancake-they are really lagging behind mft/nx with this one
I hope for crisp and clear ISO 25600 image from A77 prototype.
Ehehehe.. Ok.. My FF lenses are in search of a daddy!! Maybe I’ll buy A77 in the meanwhile if it doesn’t make compromises on light losses or IQ. 🙂
Sony give us a wide prime like the 16mm or 17mm f2.8!!!!
I won’t shed a tear when phase detect autofocus is gone. Focus shift and calibration issues have ruined an uncountable numbers of shots, resulted in the return of huge numbers of otherwise fine lenses and wasted many a photographer’s hours fiddling with micro focus adjustments.
I hear you there carl,
i’m much happy with my gh1 AF then my 300D/40D pd, which i hade to calibrate and even after that it wasnt 100% reliable
CDAF won’t solve focus shift as it still AF’s wide-open (or at a fixed working aperture) so focus shift still happens with lenses that are prone to it. It is immune to front/back focus though.
Depends on how it’s implemented. If the focusing takes place at the target aperture then it’ll be compensated for, if it’s done at an arbitrary fixed aperture like f2.8 or f5.6, then no.
The reason that cameras currently autofocus at a fixed aperture is due to the quirks of PDAF (limited baselength of their rangefinders making them too inaccurate at wide apertures and the sensors don’t get enough light to focus accurately at narrow ones), but with contrast autofocus they can simply gain up the sensor in low light.
Carl, I am not familiar with these issues though have seen them mentioned over the years. Would the integration of the PD sensors into the main image sensor eliminate some of these calibration problems?
Afraid not, those issues are simply the normal behavour of phase based focusing systems. Convergent rangefinder and split prism manual focusing aids share the same problems, as they work off the same principle.
It became the normal focusing method because it’s not possible to detect image contrast off film, and hasn’t changed since the digital revolution because film era lenses focus very slowly using CDAF. A throwback, in other words.
A couple of things I noticed about this patent. It’s priority date i.e. when the first filing was made is nearly 3 years ago (Sept. 2008) which by my estimation is enough time for the technology to be ready for deployment. The other point is that the cited prior art (other patents already published) did not include anything from Fuji, maybe their patents were not published at that time. My reading looking at the DPReview article and the Sony Patent is that the two systems are fundamentally quite similar in that they exploit the micro-lens and pixel masking (in effect) to provide the phase detection sensor pair.
So, could it be possible that Sony have this ready to go in the new NEX and SLT cameras? It would be a big step forward to have really fast auto-focus on NEX. But what about the SLT cameras? This sensor might help to further reduce their cost and eliminate the mirror but conceptually at least the SLT and DSLR would become a bit obsolete; a physical body defined by the A mount rather than the internal functions.
One other point is that the Fuji technology was introduced last year (2010) but I am not sure that it has been retained this year. Their marketing implies that CD focus now achieves the same speed as PD did before.
http://www.amazon.co.uk/Fujifilm-FinePix-F550-Digital-Camera/dp/B004G8Q5Z6/ref=sr_1_1?s=electronics&ie=UTF8&qid=1308397847&sr=1-1
http://www.amazon.co.uk/Fujifilm-FinePix-F300EXR-Digital-Camera/dp/B003VTZ7TG/ref=sr_1_1?ie=UTF8&qid=1308398300&sr=8-1
hi cow, long time no see 😀 doing good there ^^
I wouldn’t bet too much on Olympus’s speed claims, they have a history of significantly overstating their AF performance. Remember the E-3/12-60 SWD ‘Worlds Fastest AF’? Reality was performance which lagged the late 90’s crop of pro film SLRs.
Frankly, I’d suspect they’ve got something which makes them competitive with Panasonic’s CDAF, not something which puts them truly competitive with faster DSLR’s (Panasonic already can rival lower-end DSLR’s in terms of AF speed).
Minolta also had a history of overstating their AF performance. I guess no company is going to meekly raise their hand and go “okay, our autofocus system sucks”, though.
Depends. In raw speed they were always toe-to-toe with competitors when comparing similar lenses. I don’t think the motive-following focusing is good, and it never was, IMO. Also, the algorithms when using wide focus areas isn’t very good compared to Nikon.
Ever seen a E-3 or even e-5 with the 12-60 SWD? It really is fastest AF alive. Even Canikon fanatics admit it.
That doesnt change the fact, that Oly hasnt got any Camera that can compete against canikons Pro-series.
But in terms of Lenses, Olympus SHG series is unreached.
And so is the 12-60 in terms of speed.
> Remember the E-3/12-60 SWD ‘Worlds Fastest AF’? Reality was performance which lagged the late 90′s crop of pro film SLRs.
Could it be that you had a faulty one? (Or you are just trolling??)
I do not have E-3, but on E-620 the AF with 12-60 is either fast or more often instantaneous. Sometimes you do not even notice that it does something: half press and picture is already in focus. I haven’t seen anything faster. And I held in my hands a number of fast Nikkor zooms mounted on D300 and D300s, including couple of pro “paparazzi” lenses: the AF is fast, very fast, yet never instantaneous like with 12-60.
> So maybe Sony is wasting time with it?
Think of what further optimizations CDAF could gain if it also had the phase difference information.
I assume it will be a hybrid AF system, PD to determine how far and which direction to focus, then CD to finetune focus, best of both worlds.
better still, as the tech matures, DSLR’s could also become mirrorless.
Sony intensively implement image stacking tech (panorama, twilight) in their cameras. Next step should be stacking images for increased or selective depth of field. Soft such as CombineZP, Zerene Stacker etc. already available for image stacking to increase depth of field. Some small companies going further and e.g. Lytro tech is something for future: http://lytro.com/gallery/
… and with Lytro tech AF system is not necessary.
+1
I’d love to see a macro stack as well as exposure stack
That reminded me of something; any news about the electronic shutter replacing the mechanical?
It would be great if they could achieve on-sensor PDAF, but what good is fast AF on alpha lenses, when there is no IBIS on NEX? The biggest mistake Sony has made with NEX is going with in lens stabilization on selected lenses only.
This is really an excited news for us to wait the new NEX coming~~~