[lister6520]

I've just figured out a way to use the optical stabilization of my Sigma 150-500 for video. At first sight it seems to work almost as well as the sensor stabilization did on the K-r and might make video usable for me on the K1-ii.

I set up like so:
Movie SR - off
Camera set to manual focus
Focusing with back button (not half press shutter)
Lens AF on
Lens stabilization Mode 1

Now while shooting video if I press and hold the AF button the stabilizer is activated and remains active as long as I keep the button pressed. The stabilization is good and definitely helps a great deal, even if not as good as the ancient K-r was with sensor stabilization, and presumably still is unless they ruined also that with some firmware 'upgrade'.

I tried it out handheld at 500mm in this video. The video starts without stabilization. At 00:05 stabilizer activated and continues to be active, at 00:32 it is turned off and then at 00:50 I turned it on again. You can hear a loud 'clunk' when the stabilizer is activated/deactivated, i think it is the mechanism that locks it in place when turned off.

Dropbox - IMGP4726.MOV - Simplify your life

Next, out of curiosity, I tried to see what happens if I also activate the dreadful Movie-SR. Surprisingly it seems to work very well in conjunction with the in lens stabilisation as it now has to correct only for much smaller movement and causes no jello effect. This is possible because the Movie-SR doesn't use the gyroscopes so it won't be undoing the work of the in lens stabilizer as would happen when using IBIS in stills.

I'm still not sure if it is better with both systems on or just the in-lens. This next video is with Movie-SR on and again turning on/off the in-lens stabilization. It starts with in lens stab off, then turned on at 00:03 and off again at 00:48. The Movie-SR on its own is unusable as can be seen after 00:48 where it is worse than the unstabilized sections of the previous video. When in conjunction with the lens stabilization it is both better and worse. There is some jello effect but it is quite small but in compensation the image becomes almost rock steady.

Dropbox - IMGP4728.MOV - Simplify your life

Of course holding the AF button for any length of time is not very practical but if the same works with the focusing set to half press of the shutter button (which I haven;t tried yet) then its just a matter of modifying a remote shutter release so it can lock in half press. That will be able to keep the stabilizer on indefinitely without having to hold anything.

The 150-500 is the only lens I have with built in stabilization. I am guessing it will work the same with other stabilized lenses as well.

[tncowdaddy]

Very interesting. I don't have any lenses with stabilization, so it doesn't help me directly, but thanks for sharing. I'm curious as to how you figured this out. Working through different setups? Trial and error? Dumb luck?

[lister6520]

Very interesting. I don't have any lenses with stabilization, so it doesn't help me directly, but thanks for sharing. I'm curious as to how you figured this out. Working through different setups? Trial and error? Dumb luck?

It was something that just occurred to me out of the blue so to speak, it must have followed on from something else I was thinking about but I've no idea what that was. I just thought that since the stabilizer is normally activated by half press of the shutter (intended to have it ready by the time the shutter is released) then maybe it would activate also with the focus back button when autofocus is turned off, whether it would do so also in video and more importantly if it would stay active or just turn itself off again after a few seconds. A couple of days later I tried it and it worked just as I thought it might.

In the meantime I also discovered a disturbing problem with the in lens stabilization for still photo shooting that perhaps explains many blurred photos I got with this lens when using the in lens stabilization instead of the in-body. When using the back button focus (so half press doesn't focus) the shutter half press does not activate the stabilizer in the lens. I always use the back button and very often pre-focus with it and then shoot several shots without refocusing (because the subject would not be changing distance). The problem I now realize is that a few seconds after releasing the focus button the stabilizer deactivates meaning that all shots after that will be unstabilized.

I have often stated that I get more reliable results with the in body stabilization than the in lens and now I'm wondering whether this is the reason rather than an actual difference in performance between the two, and I don't know how it took me seven years to realize this. I think this more or less rules out using the in lens stabilization in conjunction with back button focusing in most situations.

---------- Post added 10-09-20 at 09:03 PM ----------

PS: I just tried it with the K-3 and it seems to work exactly the same as the K1-ii.

[Sqideyes]

Just checked this with my Bigma 50-500 and K1. I have my AF set to AF1 in button customization and in lens stabilization turns on and focuses when I press rear AF button (BBF). This setting also gives you half press shutter button focus. If you want to use BBF and recompose, holding
down the rear AF button cancels out the half press focus on the shutter button. This may work with your 150-500.