IBIS not working with new Samyang AF 12mm?

Noracsa wrote:

Hello everyone!

I've just bought the new Samyang AF 12mm 2.0 lens for my Fuji X-S10 camera. I've been using the MF version of that lens for quite some time.

Entering the focal lenght in the mount adaptor settings, I have been able to use the IBIS with the old MF lens. Thereby I could easily hand-hold shutter speeds of 1/2s and often even 1s, with images generally being tack sharp.

Really, that's a lot. Do you still own the MF version? Can you directly compare with the AF version?

Now with the new one, which automatically transmits its focal length of 12mm to the camera (checked the EXIF), IBIS doesn't seem to work, even though it's correctly turned on. I've tried both IS Modes: 1 and 2.

I have no chance of getting good sharpness with shutter speeds of 1/2s.

1/2 s is really a lot.

Even with 1/8s oder 1/15s the rate of blurry images is quite high. Turning IS off confirms this, as there is now difference in image sharpness between IS mode "off" and "1" or "2".

It's of course not easy to provoke the same shake for every photo. I recommend to shoot a few photos directly in a sequence. You probably did so.

Has anyone else had these problems? Is there a general problem of Fuji bodies not using IS with electronically connected third party lenses?

It seems odd, as the correct focal length is clearly transmitted, but the X-S10 just refuses to use the IS. Firmware is the newest v2.10 btw.

Thanks!

So as I just wrote in this thread that I quickly tried with my Viltrox 23 mm f/1.4, and IBIS does work. I simply compared a few handheld shots with IBIS ('shooting only') on and off, and the difference is clearly noticeable. What I do no know is to what extent IBIS works with the Viltrox lens.

Also with manual lenses that do not transmit Exif data, IBIS does work. Again, there is the question on the extent of camera shake mitigation.

Here comes my hypothesis.

1. In order to use the full potential of IBIS, the body needs to have information on the image circle of the respective lens. This is certainly given for any Fujifilm lens. Probably also with the Tokina AF lenses. Not sure about the Viltrox and Samyang AF lenses. Definitely not with manual lenses. My hypothesis is that the camera takes a conservative assumption in case there is no information on the image circle, i.e., IBIS will not play its full potential.
2. As per the Samyang AF lens, I don't own it. I would appreciate other users to try to confirm hat it really does not work at all. If IBIS does really not work at all, it was my first hypothesis that the lens wrongly delivers an "OIS switched off" information to the camera. But then the menu item should be grayed out. This is obviously not the case. So my hypothesis cannot be true. No idea, to be honest.

Feedback welcome.

Regards,

Martin