How long do i have to wait for continous AF on VDSLR?

[MK5GTI]

ok, i don't shoot movies, i only use the video function to shoot home videos, my daughter start running around, and i want to be able to continously focus, i tried manual focus, but i am not as fast as my daughter.

the Nikon D7000 sounds very tempt, as well as the Sony A55, or even the A77 which should come early to mid next year.  Before i make the jump to Nikon/Sony, i would like to see what Canon "will" offer me.

if they offer continous AF:

1) would they introduce in the lower end model (T3i) or in the higher end model (5D3) ?

2) do you see any other methods beside contrast detection and translucent mirror?

thanks!

[neuroanatomist]

if they offer continous AF:

1) would they introduce in the lower end model (T3i) or in the higher end model (5D3) ?

2) do you see any other methods beside contrast detection and translucent mirror?

My guess would be a T3i for the introduction of the feature, based on timing.  If they do, they can't wait too long to release the 5DIII, though.

In a dSLR, I don't see any other method.  In the pro video market, there are other options (non-TTL), but for cost and size reasons those aren't feasible for a dSLR. 

[richy]

I would agree with expecting it on a lower end camera first due to product cycle lengths, although it could appear first on the 5d3 depending on when that is launched.

As for how, haven't fuji built phase detect af onto a p&s sensor? That is another route I'm not sure at what point it becomes more of a pain in the ass to do and how much it might risk the stills side IQ (and how much canons video guys are crying that the stills boys can't have AF video as it would hurt their sales). Would be nice to see. With practice you should get fast enough at MF anyway.

[Macadameane]

It would be nice if Canon would focus more on adapting the vdslr market to more usable video cameras.  I know some kinks need to be worked out, but its probably better business for them in the long run.  When people start looking into DSLRs for video, they think, "Oh, I really want all these lenses too"  Not so when purchasing cameras like the XH-A1 or even newer ones.

We all know canon really wants to sell lenses.

[scalesusa]

No one has yet figured out how to do a good job at it.  Reviews of the AF on the Nikon D3100 (Same AF as D7---??) are not good.  The Sony camera will only AF continuously at max aperture.

If they had a method that worked well, you can bet it would be in new models, but everything is a compromise, and the manufacturer has to decide on priorities.  For what is basically a still camera, video autofocus will not be improved at the expense of still autofocus.

[kubelik]

at least part of the problem is the sound of the camera AF motors when focusing during video ... I'd rather pull focus than listen to that racket

[Macadameane]

Most L lenses have quiet focus.  Besides, you really need a separate mic / input system when filming on DSLR

[DetlevCM]

Just a little thought from my side on this...

For AF you need to detect contrast - i.e.  a small image sensor of some sort.

Someone mentioned AF on the sensor - I suspect that would be doable, provided you can read out individual lines of pixels on the sensor. Considering that Video does not need all pixels on an SLR's sensor, they would be available, on that note though, I'd doubt it.

The key problem is really "how to get two things to look through one lens" - i..e how to get an AF sensor and an image sensor to look through one lens.
And solution will be a compromise.

On the issue of manual focus - practice a bit and you'll see it's not  that hard to do acceptably. Being good yes, but getting a viewable image, no.

[clicstudio]

I have a 1D Mark IV with a 24-70 F2.8L. I love the video quality of it but using it like a video camera is just impossible.
FIrst of all, it's too heavy and bulky. Moving the focusing ring sucks. The screen is not moveable so you have to keep your eyes on the display and that means keeping the camera away from your body, which creates more instability. When the image is out of focus, it's hard to figure out which way to move the focusing ring. Sometimes, you get lucky and it focuses, but if you go the other way, there will be a couple of seconds of out of focus video.
I don't understand the big problem.1920x1080 Full HD video is only about 2MP. On a 16MP sensor, only a portion of it is used for video.
My camera can take 10fps. That's just a third of 30fps and at full 16MP. Why can't the camera use just the part of the sensor for video and the rest for the AF in servo mode at 30fps?

I don't know how video cameras do it. i have a $300 Panasonic SX1 Full HD camcorder with an 8GB SD Card. This thing has the fastest focusing i've ever seen. It focuses from macro (about 1/2") to infinity without even blinking. The quality is AVCHD. More than enough for most but of course, it doesn't compare to the Canon and a good F2.8 lens. I think they already know what to do with VDSLR AF, but releasing a camera that will basically kill professional camcorders probably won't happen any time soon.
I bet the people at RED and such are super pissed off at the 5D II and all the money film makers are saving with cameras like it.

[DetlevCM]

I have a 1D Mark IV with a 24-70 F2.8L. I love the video quality of it but using it like a video camera is just impossible.
FIrst of all, it's too heavy and bulky. Moving the focusing ring sucks. The screen is not moveable so you have to keep your eyes on the display and that means keeping the camera away from your body, which creates more instability. When the image is out of focus, it's hard to figure out which way to move the focusing ring. Sometimes, you get lucky and it focuses, but if you go the other way, there will be a couple of seconds of out of focus video.
I don't understand the big problem.1920x1080 Full HD video is only about 2MP. On a 16MP sensor, only a portion of it is used for video.
My camera can take 10fps. That's just a third of 30fps and at full 16MP. Why can't the camera use just the part of the sensor for video and the rest for the AF in servo mode at 30fps?

I don't know how video cameras do it. i have a $300 Panasonic SX1 Full HD camcorder with an 8GB SD Card. This thing has the fastest focusing i've ever seen. It focuses from macro (about 1/2") to infinity without even blinking. The quality is AVCHD. More than enough for most but of course, it doesn't compare to the Canon and a good F2.8 lens. I think they already know what to do with VDSLR AF, but releasing a camera that will basically kill professional camcorders probably won't happen any time soon.
I bet the people at RED and such are super pissed off at the 5D II and all the money film makers are saving with cameras like it.

There is a simple answer
In Video Cameras you can design the sensor accordingly from the start, the hardware only has to do the video encoding - it's built for video.

On that note though, if you really want to record video on a Canon DSLR, then buy an appropriate rig, with an LCD, follow focus and what else comes with it.

It wasn't really designed to be a fully featured video camera - it just developed into one.

[foobar]

Panasonic has pretty much nailed continous AF on their 4/3 models. Works just like any point'n'shoot camcorder in that respect, much better than what I have seen from Nikon's system (no focus hunting). It's great for people who just want to take some videos on-the-fly without having to buy a seperate camcorder for that.

For professional work, manual video settings + manual focus with an appropriate rig is still the way to go (automatic AF is too unpredictable for that).

[aberz]

Panasonic has pretty much nailed continous AF on their 4/3 models. Works just like any point'n'shoot camcorder in that respect, much better than what I have seen from Nikon's system (no focus hunting). It's great for people who just want to take some videos on-the-fly without having to buy a seperate camcorder for that.

For professional work, manual video settings + manual focus with an appropriate rig is still the way to go (automatic AF is too unpredictable for that).

+1
For PROFESSIONAL video work, AF is a no no , even on prosumer camera.
So it all come down to who Canon/Nikon want to please . For casual point and shoot video, then this would come in handy. But this is not really a desirable feature for HDSLR video maker, they should spend money to research something else. I would not hurt to have video AF tho

In the video world, everything should be set to manual.

[clicstudio]

There is a simple answer
In Video Cameras you can design the sensor accordingly from the start, the hardware only has to do the video encoding - it's built for video.

On that note though, if you really want to record video on a Canon DSLR, then buy an appropriate rig, with an LCD, follow focus and what else comes with it.

Again, why can't they just use an optimized small portion of the sensor for video and the rest for stills? If it all comes down to room in the camera and money, most DSLR's, even the small Rebels can fit an extra hybrid sensor in there, not to mention there is plenty of room on the 1D's for a lot more than they have crammed in there. 

It's time someone does something radical. A hybrid 18MP camera (16MP for stills and 2MP for HD video), mirror-less if u want, with a 4" articulating touch LCD and live view thru the view finder. 

Hey dreams are free 

[DetlevCM]

There is a simple answer
In Video Cameras you can design the sensor accordingly from the start, the hardware only has to do the video encoding - it's built for video.

On that note though, if you really want to record video on a Canon DSLR, then buy an appropriate rig, with an LCD, follow focus and what else comes with it.

Again, why can't they just use an optimized small portion of the sensor for video and the rest for stills? If it all comes down to room in the camera and money, most DSLR's, even the small Rebels can fit an extra hybrid sensor in there, not to mention there is plenty of room on the 1D's for a lot more than they have crammed in there. 

It's time someone does something radical. A hybrid 18MP camera (16MP for stills and 2MP for HD video), mirror-less if u want, with a 4" articulating touch LCD and live view thru the view finder. 

Hey dreams are free 

It would require a complete sensor redesign -> expensive.
Money is pretty much the issue.
Dual sensors would be nonsense - and trying to build 2 sensors in 1 as well, as you'd loose lines and columsn for stills.

If you were to move the focussing to the sensor you must be able to read out some lines individually from the rest of the sensor - doable... but at what cost.

That's why a RED is so much more expensive.
On that note... I wonder when Canon releases a DSLR that does 4K footage (from Canon, no spoofs) - the resolution is there on the sensor, our CF bandwidths (or use something else?) are also constantly increasing...

[Bob Howland]

There is a simple answer
In Video Cameras you can design the sensor accordingly from the start, the hardware only has to do the video encoding - it's built for video.

On that note though, if you really want to record video on a Canon DSLR, then buy an appropriate rig, with an LCD, follow focus and what else comes with it.

Again, why can't they just use an optimized small portion of the sensor for video and the rest for stills? If it all comes down to room in the camera and money, most DSLR's, even the small Rebels can fit an extra hybrid sensor in there, not to mention there is plenty of room on the 1D's for a lot more than they have crammed in there. 

It's time someone does something radical. A hybrid 18MP camera (16MP for stills and 2MP for HD video), mirror-less if u want, with a 4" articulating touch LCD and live view thru the view finder. 

Hey dreams are free 

It would require a complete sensor redesign -> expensive.
Money is pretty much the issue.
Dual sensors would be nonsense - and trying to build 2 sensors in 1 as well, as you'd loose lines and columsn for stills.

If you were to move the focussing to the sensor you must be able to read out some lines individually from the rest of the sensor - doable... but at what cost.

That's why a RED is so much more expensive.
On that note... I wonder when Canon releases a DSLR that does 4K footage (from Canon, no spoofs) - the resolution is there on the sensor, our CF bandwidths (or use something else?) are also constantly increasing...

My Panasonic HDC-TM700 video camera has three sensors, one each for red, green and blue, and a street price of about $800. Granted, each sensor is really small (1/4.1") and has only slightly more than 2mp, but there are three of them. However, the overall construction and feature set is definitely high end consumer camcorder rather than professional camcorder. A 3-sensor configuration is also used for the Canon XF300/305 but the sensors themselves are larger and the cameras' overall construction and feature sets are definitely professional level. (The BBC just bought 50 XF305s for documentary use.) The XF305 costs $8000 in the U.S.

One thing that has become abundantly clear with the CES video camera introductions from Canon and Panasonic is that still image quality is being de-emphasized in consumer video cameras. Those manufacturers (and Sony) seem much more interested in getting better video quality in low light. The Canon M40, M41, M400, G10 and XA10 all use a single 2.07MP sensor, although it's a comparatively large 1/3" size, the same size used in the XF300/305. These five cameras list for less than $2000, with the M-series costing much less. On the other hand, the Sony PMW-F3 uses a single nearly-APS-C size sensor and takes interchangeable lenses but it is definitely a pro model and costs $13,300 without a lens.

So a reasonable conclusion is that something similar to a 3-sensor beam splitter could be used to route light to two fairly small but differently-purposed sensors, one optimized for still images and one optimized for HD video. I leave the definitions of "optimized" to you.