Web Analytics RiceHigh's Pentax Blog: New Phase Detection Method and Patent by Using the SR System

Monday, August 04, 2014

New Phase Detection Method and Patent by Using the SR System

http://dc.nphoto.net/news/2014-07/28/aee3821ee9506bf2.shtml
(in Chinese)

Comments (13)

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Very interesting. But I wonder, is it possible to focus by moving sensor forward and backward? I don’t mean full way autofocus, thus it needs very large travel. But precise focusing after rough manual pointing could be a great feature. It could be useful for AF lenses too, when shooting in complex conditions, where manual prefocus is preferred.

However, as soon as I know, even 5-axis sensor stabilization systems miss front-forward movement. Perhaps Ricoh will be able to overcome troubles.
3 replies · active 554 weeks ago
Contax AX focused by moving the film plane, thus it could do AF with manual focus lenses. https://www.youtube.com/watch?v=MjgV34PzKTA
The Ricoh patent doesn't say the sensor is moving forward or backward. I found this interesting comment using Google which may be correct:

"I think this method shifts the sensor a little to get information from two points to perform phase detect autofocus. In other words, instead of having some pixels on the sensor dedicated to PDAF or splitting each pixel in two (like Canon's dual pixel system), this idea moves the sensor to get the same information. It means Ricoh could have on sensor PDAF without having to make a specific sensor".
I think you are correct and that is how I am reading it as well. This sounds like something that has limited use IMO. First of all the sensor doesn't have any movement front to back in the center and your ability to collect meaningful information increases as you get to the edges. I'm getting that it is a method for phase detection using the sensor and SR combined, but I really don't understand how they could have implemented that. Also how does this work with video? its not like you can just vibrate the sensor around and get readings in real time while it is recording. I really like Pentax's SR implementation, which has noticeably improved since the K10D and is very good in the K-5 IIs I am using.
This is really good news. They are trying something new to improve autofocus instead of just painting the shake reduction mechanism a new color.
A clever design. Keep up, Ricoh.
A Beauty!
Glad to know I have a better metallic replacement option for my original Q, in case it breaks.
1 reply · active 554 weeks ago
Not from me. Comment not for this post.
OS is better's avatar

OS is better · 554 weeks ago

Personally, I turn off SR. It gets in the way of taking pictures waiting for the green hand. It pictures really important and time needed, I use tripod.

Time for optical stabilization thanks.
4 replies · active 553 weeks ago
First, SR stabilization is also completely optical, it involves laws of optics. Second, it is not slower. Then, it is more universal. Then, if the design indicated by this patent will be implemented, it will be a real bonus.
SR kicks in whenever needed, you don't have to wait for anything. Just shoot as you are used to and let the SR do it's job...
It actually takes a split second for SR to activate. About the period of time you should be using to check your composition/settings anyways. I myself never worry about the green hand and just shoot anyways. If its a picture worth keeping I'll take two or three in rapid succession. Usually SR will kick on by the 2nd in a worst case scenario.
The SR needs the hand shake symbol to light up before it is stable, otherwise the hit rate is low. It takes one to two seconds to achieve that and thus there is always a lag.

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