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IBIS issue A7II
- Thread starter Viramati
- Start date
Thanks. Fame at last!!
Last edited:
k-hawinkler
Well-known member
is this correct? Sony A7II IBIS issue - FM Forums, post #20?, quote:
"Post icon p.1 #20 · Sony A7II IBIS issue
Ok, let's backup and try to understand what is going on here. The five axis stabilization is stabilized in five ways. Let's start with the easiest, roll, that is movement like turning a steering wheel. For hard shutter pressers this is certainly a problem, but less so for soft shutter pressers. This is always provided for by the camera.
The next axis to consider is "X," if you have done any graphing then you know that the X axis is the horizontal axis. The sensor can control for movement that is horizontal, but to do so it has to have distance information from the lens. How far the sensor needs to move left or right is dependent on how far one is focussing. If it is close up the sensor needs to move more, if the focus is far away it hardly needs to move at all.
The "Y" axis stabilization, like graphing is on the vertical axis. It works like X axis stabilization but the sensor moves up and down and just like X axis stabilization the camera has to know the focus distance to adequately compensate for movement. If the focus distance is close more adjustment is needed that if the focus distance is far away.
Now because X and Y axis stabilization is done by moving the sensor, it has to be done by the camera, but it also requires a lens that reports distance information to the camera. When a lens doesn't do that, (almost all alt lenses and even some A mount Sony lenses), they you won't get this type of stabilization.
Pitch is the next axis to consider. This isn't straight up and down movement like Y axis stabilization, it is forward and backward movement that tips up and down at the the same time. If you have ever flown a plane or tried a flight simulator, imagine the movement that is required to make the plane go down for a landing or go up at take off. This is pitch movement. This can be compensated for regardless of focal distance and Sony OSS lenses compensate on this axis. The sensor does as well with not OSS lenses. Now Sony has cleverly designed the new system in the A7 II so that pitch compensation is shut off in the camera with an OSS lens is attached and the lens provides pitch compensation.
Yaw is the last axis to consider. This isn't straight left or right like X axis compensation, but is right forward/left back or left forward/right back. Again thinking of an air plane controller can help. If you want the plane to bank left you push in on the right controller. If you want the plan to bank right you push in on the left controller. This axis like pitch is controlled by the lens with OSS lenses, and is shut off in the camera with those lenses. With non-OSS lenses (including alt lenses) it is provided by the camera.
What does this mean for the current discussion? It means that using an OSS lens shuts off pitch and yaw compensation. If you put an alt lens on, you lose pitch and yaw compensation. Because these lenses don't convey focus distance information, you can't have X or Y compensation either. I would hazard a guess that you do get roll compensation (and that is probably why viramati still hears a whir), but that isn't going to help much. We need to know what turns the pitch and yaw compensation back on. It seems taking the battery out might be one thing, but we are hearing different things about that. Mounting a FE non-OSS lens definitely works. Turning off the camera doesn't work. And mounting other lenses with adapter that communicate with the camera may or may not work (it seems that using the LAEA-4 adapter with an A-mount camera does work although it still needs to be confirmed that 8 pin adapters that convey focus distance information and 5 pin adapters that don't both work)."
According to this post, image stabilization for a third party lens, e.g. Leica M, would come from pitch, yaw, and roll stabilization from the camera body.
So, I now wonder how Olympus does it for the E-M5 and E-M1?
There one enters lens focal length for third party lenses but, of course, not focus distance information. I forgot once to update the focal length setting and IBIS overcorrected. That was easy to spot.
"Post icon p.1 #20 · Sony A7II IBIS issue
Ok, let's backup and try to understand what is going on here. The five axis stabilization is stabilized in five ways. Let's start with the easiest, roll, that is movement like turning a steering wheel. For hard shutter pressers this is certainly a problem, but less so for soft shutter pressers. This is always provided for by the camera.
The next axis to consider is "X," if you have done any graphing then you know that the X axis is the horizontal axis. The sensor can control for movement that is horizontal, but to do so it has to have distance information from the lens. How far the sensor needs to move left or right is dependent on how far one is focussing. If it is close up the sensor needs to move more, if the focus is far away it hardly needs to move at all.
The "Y" axis stabilization, like graphing is on the vertical axis. It works like X axis stabilization but the sensor moves up and down and just like X axis stabilization the camera has to know the focus distance to adequately compensate for movement. If the focus distance is close more adjustment is needed that if the focus distance is far away.
Now because X and Y axis stabilization is done by moving the sensor, it has to be done by the camera, but it also requires a lens that reports distance information to the camera. When a lens doesn't do that, (almost all alt lenses and even some A mount Sony lenses), they you won't get this type of stabilization.
Pitch is the next axis to consider. This isn't straight up and down movement like Y axis stabilization, it is forward and backward movement that tips up and down at the the same time. If you have ever flown a plane or tried a flight simulator, imagine the movement that is required to make the plane go down for a landing or go up at take off. This is pitch movement. This can be compensated for regardless of focal distance and Sony OSS lenses compensate on this axis. The sensor does as well with not OSS lenses. Now Sony has cleverly designed the new system in the A7 II so that pitch compensation is shut off in the camera with an OSS lens is attached and the lens provides pitch compensation.
Yaw is the last axis to consider. This isn't straight left or right like X axis compensation, but is right forward/left back or left forward/right back. Again thinking of an air plane controller can help. If you want the plane to bank left you push in on the right controller. If you want the plan to bank right you push in on the left controller. This axis like pitch is controlled by the lens with OSS lenses, and is shut off in the camera with those lenses. With non-OSS lenses (including alt lenses) it is provided by the camera.
What does this mean for the current discussion? It means that using an OSS lens shuts off pitch and yaw compensation. If you put an alt lens on, you lose pitch and yaw compensation. Because these lenses don't convey focus distance information, you can't have X or Y compensation either. I would hazard a guess that you do get roll compensation (and that is probably why viramati still hears a whir), but that isn't going to help much. We need to know what turns the pitch and yaw compensation back on. It seems taking the battery out might be one thing, but we are hearing different things about that. Mounting a FE non-OSS lens definitely works. Turning off the camera doesn't work. And mounting other lenses with adapter that communicate with the camera may or may not work (it seems that using the LAEA-4 adapter with an A-mount camera does work although it still needs to be confirmed that 8 pin adapters that convey focus distance information and 5 pin adapters that don't both work)."
According to this post, image stabilization for a third party lens, e.g. Leica M, would come from pitch, yaw, and roll stabilization from the camera body.
So, I now wonder how Olympus does it for the E-M5 and E-M1?
There one enters lens focal length for third party lenses but, of course, not focus distance information. I forgot once to update the focal length setting and IBIS overcorrected. That was easy to spot.
I presume these are mounted using an adaptor that communicates electronically with the camera in which case all maybe well.
V
Vivek
Guest
That is correct and I am hoping that when they issue a FW update to correct the issue found by David, they will offer 5 axis stabilization like Olympus (with assumed distances).
k-hawinkler
Well-known member
Thanks Vivek. That would be great!
hodad66
Member
No these are dumb adapters and manual lenses. I dial in the focal
length but with the 500 I can hardly tell if any stabilization is happening.
k-hawinkler
Well-known member
That's very surprising.
Certainly on the E-M5/1 for such a long lens whether stabilization is on or off is very obvious for handheld shots.
V
Vivek
Guest
John, Looking at your bird pictures, it is clear that your technique is perfect (solid tripod and the works). If that is the case, when there are no vibrations to deal with, why would the SS be active?
k-hawinkler
Well-known member
Yes you are right, I was too lazy to check and not recording exactly; here is one graph (there is another one including legacy glass on a third raw, but I wasn't able to find it)
I think now I understand the first row in this picture.
As there is no on/off switch on the OSS lens - so OSS is always on - pitch and yaw image stabilization in the camera body has to be switched off.
That's different from IBIS in Olymps' E-M5/1 cameras.
There one has to choose between using either the image stabilization built into the lens or that built into the camera body or neither (i.e. switch off both).
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V
Vivek
Guest
Sounds good (though a FW update in order, IMO). Could you clean up your post so that it is clear. UMOUNT means what? TIA!
jonoslack
Active member
Ah! This explains a lot. I'm a lazy beast and there are definitely times when I've done this. It might also explain Brian Smith's problem.
Would you like to email Andrea at Sonyalpharumours? I think someone should.
Congratulations David, you've saved a lot of people a lot of grief and done Sony a big favour into the bargain.
I don't think so but when you use the sensor cleaning option it really shakes it around unlike the previous models so I can only presume it uses the IBIS mechanism in some exaggerated way to shake it off
k-hawinkler
Well-known member
This is interesting as it implies that the A7II switches over from relying on the pitch and yaw image stabilization of the lens to those of the camera body, doesn't it?