On-sensor PDAF, will it be as good as mirrored cameras?

Started Oct 10, 2013 | Discussions thread
Bruce Oudekerk
Bruce Oudekerk Veteran Member • Posts: 3,457
Some related thoughts.

It seems obvious that one of the significant distinctions Sony has made between the A mount and E mount systems is that any camera that has a native E-mount will not have in-camera-stabilization and instead will rely on image stabilization using in-lens mechanisms. Certainly from a technical standpoint this is not necessarily true since others have managed this in small framed camera bodies. I suspect this single image stabilization distinction is a fundamental difference between the two Sony lens mount systems (that and compactness). And while this artificial distinction has puzzled me, there could be a rational explanation...or at least I hope there is one.

A rumor surfaced a while back about a new in-camera stabilization that quite frankly astounds me but I love the idea. It has the normal X, Y and perhaps rotational movement but also has Z component to its movement. If this is true...ever... this will be a fundamental game changer and quite frankly could be the biggest innovation in photography since digital capture, assuming that this in and out Z component is large enough, Essentially all lenses focus by moving on this Z axis and there really is no reason that ANY lens that can attach to a camera can't be made to focus via the mechanism of the sensor shifting 'in and out' on this Z axis. For example, that means that such a camera, if it existed, could use manual focus Leica lenses, old manual focus Minolta MD lenses, old Canon FD lenses and excellent brand new manual Samyang lenses and autofocus with them using some combination of on-chip phase or contrast detect. To me...even more amazing is that virtually all autofocus lenses, from any system, could also be used. Ironically that means that Sony would insure full compatibility of screw drive A-mount lenses, not using the screw drive itself but by auto focus via sensor shift. In the future new amount lenses might not even have any ability to focus except perhaps manually. Even if the rumor is wrong, I'm convinced it a good enough idea someone will eventually achieve it.

The e-mount system is designed to be lean and mean at any given price point. That means smaller lenses, thus slower lenses aperture wise. The a-mount system is designed to be more versatile and thus will be considered more of a professional camera and must be able to utilize large and bulky lenses in a hand held manner. As such I expect that the smallest a-mount cameras will not be that small and the largest e-mount cameras will not be that large and there will be no overlap regardless of what they look like. They will both be mirror less.

In my mind, assuming that this z axis sensor shift is developed by Sony, the only unknown is whether or not Sony goes broke before they achieve competitive focus speed to other systems.

Basically Sony's vision of the future is to build very sophisticated lens caps where the flange to lens distance is much larger and more versatile with the a-mount 'lens caps' and on the extreme other end of the photographic spectrum, the lens and cap are integrated in the case of the QX. I hope they can pull it off.

As an aside, image quality is hardly ever the distinction between professional system cameras and amateur level cameras. . In the hands of a good photographer the modest a3000 is capable of outstanding photographs but is hardly a 'professional' camera by anyone's metric. Instead such criteria as robust nature, versatility and ease of handling are often much more important. Versatility means many things to many people. It could be optimal low light capability, a great number of OEM accessories, the ability to utilize third party equipment, fast/accurate focusing, or the ability to effortlessly handle large and heavy lenses. It could be all of these ...or none.


 Bruce Oudekerk's gear list:Bruce Oudekerk's gear list
Sony Alpha a7R II Samyang 14mm F2.8 IF ED MC Aspherical Sony Vario-Tessar T* FE 16-35mm F4 ZA OSS Sony FE 70-300mm F4.5-5.6 G OSS Sony FE 50mm F1.8 +1 more
Post (hide subjects) Posted by
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow