IBIS not working with new Samyang AF 12mm?

Truman Prevatt wrote:

Noracsa wrote:

Rightsaidfred wrote:

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?

Yes, I still own the MF version, so I did compare directly. The difference is absolutely clear with every 1/2s shot of the MF version being sharp and almost all AF version shots being blurred.

I've also just tested the AF version not being correctly mounted but rotated so that the electronic contacts don't work: The camera then uses the mount adaptor setting of 12mm and all images come out sharp.

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.

Well for a 12mm lens the classic formular would tranlate to a shutter speed of 1/18s. So 1/2 is a little bit over 3 stops of stabilization.

Fuji claims the X-S10 to have 5 stops of stabilization, so 1/2s seems reasonable at 12mm and, like I said, I get consistently sharp images a that speed unsing the MF version.

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.

Thanks for confirming that it does work with your Viltrox lens.

Regarding your hypothesis 1: Since the IBIS works perectly fine with the MF version, there shouldn't be any problems with the image circle of the camera making a too conservative assumption.

Regarding your hypothesis 2: I think that could be the case. Some kind of lens information, telling the body not to use IBIS.

This could be a general bug on Samyangs side, then others should be able to confirm this.

Or it's just a bad copy on my side, which would be suprising, as such singular lens software differences are rather unlikely.

Maybe It's just a bug of my Fuji X-S10. However, the camera's IBIS works well with my Fuji 16mm 1.4.

So any feedback of other users of the Samyang AF 12mm would be very appreciated.

Clearly either Samyang screwed up the communications protocol to the camera, there is a lens F/W bug or the lens has a H/W issue. If the camera will use IBIS with A/F lenses and with M/F lenses then the issue is with the lens. Return it.

What Truman said, but before doing so, I’d love to see some 1/2 and 1 second images that are tack sharp. It would enlighten me to the IBIS capabilities of the X-S10.