# Lightning-fast AF speed in a CYBER-SHOT??



## whatta (Jan 30, 2012)

Hello,

I know it is not a canon, but still I find it interesting, especially for the dslr vs mirrorless topic.

Press release from sony

http://www.dpreview.com/news/2012/01/30/Sony_DSC-TX200V_DSC-WX70_DSC-WX50

"_Lightning-fast AF speed of approximately 0.13 second in daylight, 0.25 seconds in low-light (speeds may vary based on shooting conditions)_"

"_In its description of the TX200V's fast AF, Sony suggests that the camera compares out-of-focus images to determine which direction to move the lens to achieve focus, avoiding the camera scanning for focus in the wrong direction. This sounds a lot like phase-detection to us but we're still chasing for more information._"

It uses btw "_Sony's latest 18MP *back-lit* CMOS sensor_"

any thoughts?

thanks


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## Mt Spokane Photography (Jan 30, 2012)

It certainly sounds like a big improvement. Camera makers are starting to pay attention to the slow AF in their point and shoot bodies, so I hope it spreads to all models.

Unfortunately, Sony (and others as well) push the positive aspects, and then, later, we find out the take-aways that go with it. It will be interesting to see a review of a production body, not that I'd buy one, but to see how it actually works, and what the downsides might be.


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## EYEONE (Jan 30, 2012)

Of course P&S cameras have larger depths of field and smaller lens elements so focusing is much easier.

But, either way contrast based AF is catching up to phase-detection very quickly. And phase-detection seems about as fast as it can be. I know Sony was working on phase detection built into the sensor but I'm not sure this is even necessary at this point.


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## Mappy (Jan 30, 2012)

press_release_from_sony said:


> This sounds a lot like phase-detection to us


It sounds like the system just takes a picture, measures the amount of blur, then starts zooming in one direction and takes another picture. Now it compares the blurriness of the two pictures and decides to continue focusing in that direction, or to focus in the other direction without hitting the front or back focus stop.
Comparing the blur on images can also give you an idea about how much further you have to go to focus, so you could speed the focus motor up and in the meantime keep adjusting your target by taking new pictures to compare. 
Sounds mostly like a faster processor to do more math so focusing can be done faster.


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## tt (Feb 5, 2012)

http://www.guardian.co.uk/global/2012/jan/15/digital-auto-focus-defocus-technology

Reminds me of this - not sure if it's phase detection so much of how blurry is the blurry thing


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## qurgin (Aug 18, 2012)

impressive. quote from the press release:

The advanced Sony TX200V digital camera offers extreme *fast AutoFocus speeds of approximately 0.13 seconds* in daytime and 0.25 seconds in low-light situations (speeds may vary based on shooting conditions), helping to ensure you never miss the moment. The new Sony CyberShot DSC-TX200 camera features a new "Extra High Sensitivity" technology, which minimizes unwanted noise in low-light shooting conditions. The Sony DSC-TX200V digital camera also offers image stabilization during video and still shooting. Using technology borrowed from the Sony Handycam line-up, the "Optical Steady Shot Active Mode" drastically reduces blurring caused by camera shake while on the move. The Sony TX200V can shoot video in Full HD 1080p resolution at 60fps. For consumers who want to get closer to their subjects without losing quality, the Sony DSC-TX200V offers "Clear Image Zoom" technology, which boosts optical zoom to 2x virtual capability (becoming 10x virtual zoom) at Full camera resolution


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