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Tech wonders: Oly's predictive focus for fast AF

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amalric

amalric

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amalric said:
Perhaps the mystery of fast AF is unveiled, here:

http://mirrorlesscam.com/forum/viewtopic.php?f=13&t=57&start=9999

Two images are buffered and compared, one in IR.

Con: work only if IR works: no filters allowed

Con: won't work with old lenses because lens should let through IR to sensor.

Assuming I understood well, and the leak is true :)

If so, Oly you're great!
Click to expand...
Yes, great. Maybe I'm ignorant, but IR light should make it through all filters and lenses in any case, wouldn't it? It's not UV.
 
amalric said:
Perhaps the mystery of fast AF is unveiled, here:

http://mirrorlesscam.com/forum/viewtopic.php?f=13&t=57&start=9999

Two images are buffered and compared, one in IR.

Con: work only if IR works: no filters allowed

Con: won't work with old lenses because lens should let through IR to sensor.

Assuming I understood well, and the leak is true :)

If so, Oly you're great!
Click to expand...
I agree, if it's true, seems like a really brilliant solution. A system like this can seriously doom PDAF, and also it would mean great focusing ability in low (or no) light!
I'm getting excited.
 
makes me wonder if that AF assist light is an IR emitter.. or if their future flashes will have IR emitters to assist in focusing. its an interesting solution for sure. It also eats up a fair amount of sensor real estate since.

i think it works by comparing the offset of each image. if you assign a focus point, it will look at the offset and adjust the focus to reduce it.. im not sure how this can be predictive though, it still needs to know to move in or out
amalric said:
Perhaps the mystery of fast AF is unveiled, here:

http://mirrorlesscam.com/forum/viewtopic.php?f=13&t=57&start=9999

Two images are buffered and compared, one in IR.

Con: work only if IR works: no filters allowed

Con: won't work with old lenses because lens should let through IR to sensor.

Assuming I understood well, and the leak is true :)

If so, Oly you're great!

--
Photostream: http://www.flickr.com/photos/amalric
Click to expand...
 
DirkL said:
DirkL said:
Yes, great. Maybe I'm ignorant, but IR light should make it through all filters and lenses in any case, wouldn't it? It's not UV.
Click to expand...
Click to expand...
It's true that IR light passes much more easily than UV (UV is substantially reduced also by normal glass), but some specific filter can reduce IR sensitivity.
I wonder how it goes along with the IR-cut.
 
Jogger said:
makes me wonder if that AF assist light is an IR emitter.. or if their future flashes will have IR emitters to assist in focusing. its an interesting solution for sure. It also eats up a fair amount of sensor real estate since.
Click to expand...
I don't understand why a different wavelength helps determine distance. I think that it might be an approximation of distance and that CDAF makes the final precision measurement.

Integration with IR illumination would work on short distances and in low light but it would indeed be great.

Am.
 
Jogger said:
im not sure how this can be predictive though, it still needs to know to move in or out
Click to expand...
No, it doesn't. Take a chromatic lens: blue is always focused behind red: longer wavelenghts are always deflected more than shorter ones. So the camera has to decide which of the two (IR or G) is "more out of focus" and react consequently.
 
the other interesting thing is that digital sensors are sensitive to IR but not UV ... which is why they have that IR filter in the first place to avoid red shifts. are they just going to remove the IR cut filter??? they cant have a sensor thats sensitive and not sensitive to IR unless they move the IR cut filter down to the microlenses level
trmz said:
DirkL said:
trmz said:
Yes, great. Maybe I'm ignorant, but IR light should make it through all filters and lenses in any case, wouldn't it? It's not UV.
Click to expand...
Click to expand...
It's true that IR light passes much more easily than UV (UV is substantially reduced also by normal glass), but some specific filter can reduce IR sensitivity.
I wonder how it goes along with the IR-cut.
Click to expand...
 
--Maybe this explain the meetings of Oly with lens manufacturers ,some months ago.This kind of technology changes everything in AF problem.
river
 
To be honest, I don't quite understand the technology behind it, but if it was true, that this technolgy results in a fast and reliable predictive C-AF for µFT cameras, it would be farewell FT and welcome back µFT, for me.

That’s what I’ve been waiting for since I switched from the G1 to the E-30 and then E-5. For me – I’m shooting mainly dogs and other animals in action – this would be the greatest news since I left my P&S days behind and began regarding photography as a real hobby.
 
amalric said:
Perhaps the mystery of fast AF is unveiled, here:

http://mirrorlesscam.com/forum/viewtopic.php?f=13&t=57&start=9999

Two images are buffered and compared, one in IR.

Con: work only if IR works: no filters allowed

Con: won't work with old lenses because lens should let through IR to sensor.

Assuming I understood well, and the leak is true :)

If so, Oly you're great!
--
Click to expand...
If this is true than I don't think Qlympus implemented it the way you/they suggest. Olympus would never block filter use, nor would they make old m4/3rds lenses absolete in one blow.
THAT would be commercial suicide

--
Digifan
 
Old lenses and filtered can use CDAF the old fashion way. Also, its not like Oly has a stellar lens line-up, theyre mostly slow zooms and mediocre primes. The 12/2 is their first real lens for the system; maybe they waited to release because of this new focusing tech. The other lenses can just be updated.

Also, they dont really care what this new AF means for Panasonic lens users since they want you to buy oly anyways.
digifan said:
amalric said:
Perhaps the mystery of fast AF is unveiled, here:

http://mirrorlesscam.com/forum/viewtopic.php?f=13&t=57&start=9999

Two images are buffered and compared, one in IR.

Con: work only if IR works: no filters allowed

Con: won't work with old lenses because lens should let through IR to sensor.

Assuming I understood well, and the leak is true :)

If so, Oly you're great!
--
Click to expand...
If this is true than I don't think Qlympus implemented it the way you/they suggest. Olympus would never block filter use, nor would they make old m4/3rds lenses absolete in one blow.
THAT would be commercial suicide

--
Digifan
Click to expand...
 
Jogger said:
Old lenses and filtered can use CDAF the old fashion way. Also, its not like Oly has a stellar lens line-up, theyre mostly slow zooms and mediocre primes. The 12/2 is their first real lens for the system; maybe they waited to release because of this new focusing tech. The other lenses can just be updated.

Also, they dont really care what this new AF means for Panasonic lens users since they want you to buy oly anyways.
digifan said:
amalric said:
Perhaps the mystery of fast AF is unveiled, here:

http://mirrorlesscam.com/forum/viewtopic.php?f=13&t=57&start=9999

Two images are buffered and compared, one in IR.

Con: work only if IR works: no filters allowed

Con: won't work with old lenses because lens should let through IR to sensor.

Assuming I understood well, and the leak is true :)

If so, Oly you're great!
--
Click to expand...
If this is true than I don't think Qlympus implemented it the way you/they suggest. Olympus would never block filter use, nor would they make old m4/3rds lenses absolete in one blow.
THAT would be commercial suicide

--
Digifan
Click to expand...
Click to expand...
Maybe they are using a mirror, which is completely transparent for visible light and reflexive for infrared radiation. Then this would simply be a phase detect autofocus using infrared light without the drawbacks of the Sony solution, which filters visible light.

The infrared approach has an additional appeal in low light, because infrared is simply heat radiation. Heat radiation is usually invisible until objects are extremely hot and start to glow. In the dark, you can actually see warm objects in infrared light. This would mean that the fast autofocus should work in very bad lighting conditions. Ideal for snapping pictures of people in the dark.
 
Very neat idea. It can be predictive because you know if the IR image focus is sharper than the visible - it relies on the chromatic aberration of all lenses which means the focal length for IR is different than for visible.

My guess is that this relies on the special lens coating to pass the specific IR wavelengths so may not work with 4/3 - if they block these. If they don't then a new adaptor for 4/3 which just transmits the right wavelengths might work - anyone have experience of IR photography with 4/3 lenses?
 
ah... so the difference in 'focussed-ness' between the IR vs visible light image tells the camera which direction to focus in instead of having to guess or try both...?
 
cbr09 said:
Very neat idea. It can be predictive because you know if the IR image focus is sharper than the visible - it relies on the chromatic aberration of all lenses which means the focal length for IR is different than for visible.
Click to expand...
In the patent provided by Brian - thanks!- the text mentions CA, in the evaluator block. Does it mean that according to subject distance there is more or less CA in the visible light, while IR acts as a yardstick?
Member said:
My guess is that this relies on the special lens coating to pass the specific IR wavelengths so may not work with 4/3 - if they block these. If they don't then a new adaptor for 4/3 which just transmits the right wavelengths might work - anyone have experience of IR photography with 4/3 lenses?
Click to expand...
An IR filter?

One wonders about Panny, which also has a predicitve mode in AF. Are these proprietary? That might explain why Oly was bogged in slow AF until it developed its own system. One also wonders ig the new Oly lenses will be as fast on Panny bodies or not, and the opposite of course.

Thirdly it would be interesting to know if the system works in semi darkness thanks to the IR illuminator.

Somewhere in 43rumors, which are perhaps leaks, a new predictive focus was mentioned, so this might be the effective embodiment of the patent.

--
Photostream: http://www.flickr.com/photos/amalric
 
Is that it can't figure out how to make its systems modular and to improve a feature without having to redo the entire system.

Any lens with IR coatings will not be able to use this feature. This means again, that Olympus will have to come out with lenses with the IR coatings removed to use this feature. I am all about new technologies but not at the expense of throwing early adopters under the bus. Heck, those who purchased say the wide angle zoom aren't early adopters, but those owners won't get faster focusing because of the coating. My understanding is that Olympus has put IR blocking in their lens coatings for a while now.

I realize that the old lenses will still AF, but thats not my point. If you look at Olympus history with AF:

1. Barely acceptable with E-P1 and kit lens, even after firmware update
2. New lenses with MSC motors have better focusing capabilities
3. Redesign of kit lens for faster focusing

4. Faster focusing through the use of IR technology. Will require a new kit lens with different coatings possibly?

Panasonic has only had to redesign their kit lens once. Most of their AF improvements have not been really dependent upon the lens, rather, on faster software and reading of the sensor.

As much as I am pulling for Olympus as an Olympus user, I can't invest into a system until they get the AF right so I don't have to worry about focusing slowness with lenses and dependency issues.
 
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