I have recently purchased Laowa 7.5mm f/2 manual wide-angle lens and also updated my camera to Olympus E-M1 mark II. Unfortunately these two do not get along perfectly. Sometimes I take a set of two photos and one is sharp throughout but the other has soft corners. I believe neither of the products is defective but suspect Olympus in-body image stabiliser (IBIS) is the root cause here, not playing well with the manual lens.
Laowa 7.5 is a fully manual rectilinear ultra wide-angle lens. Focus is manual, aperture is manual, and there is no electronics to transfer any data between camera and lens. This also means it cannot really break as long as the glass is intact. I have confirmed the lens can provide very good image quality and is relatively sharp even in corners.
While the lens seems fine, I also have not seen any odd IBIS issues on the E-M1 mark II with any Olympus lens.
However, when using these together, I get inconsistent results. In the example shown below I have taken a set of two photos with identical settings, and one photo is sharp throughout but the other is soft in corners.
- Laowa 7.5mm can deliver photos that are sharp throughout so the lens seems not defective
- I have not seen this issue on E-M1 mark II with any Olympus lens; I do not have any other manual lens to try
- With E-M1II+Laowa I occasionally get images which are sharp in centre but soft in corners and/or edges
- In some cases when I take two consecutive photos without changing any setting or focus (remember this is a manual focus lens), one is sharp throughout and the other one not
Two frames – one sharp and one soft in corners
Below is an example I took few weeks ago – two consecutive frames without changing anything in between. Shutter speed is 1/3s and these are taken handheld.
Click the photos to open them in lightbox and then use the arrows to compare the two.
Here we can see that centre is sharp in both images.
Top left 1:1
Here is massive difference in sharpness. How is this possible when the centre is sharp?
Bottom right 1:1
Here in the opposite corner it is not as clear due to texture of flowing water but looking at the stones we see at least some difference in sharpness.
Top right 1:1
On top right corner difference is not as clear.
It looks like something has moved causing the focal plane to shift. I cannot think of anything else than the IBIS which is moving the sensor. In an ultra wide-angle shot corners “see” much more movement than centre when something is moving (e.g. camera shake) but the fact that only two opposite corners seem to be badly off-focus suggests rotation in the focal plane.
I took these photos of my accommodation in a recent trip to Scottish Highlands. Again, both images are sharp in the centre but the stag picture on the wall is blurry in one photo.
Top left 1:1
However, the difference in the opposite corner is not very clear in this photo.
Occurrence of the issue
I have seen the issue in quite many photos taken recently – so often that it really bothers me. I usually have just one photo like the one below, and I find it softer than expected. Without comparison, initially I was thinking the focus must be off, or the lens is decentered (faulty). But the above examples of two consecutive images clearly show that the lens is fine and focus is not an issue either.
Example of sharp photo
The lens itself is capable of delivering images with sharp corners, as shown below. This photo was taken on tripod so I suspect I may have turned the IBIS off.
Is IBIS the root cause?
I have tried to do test shoots but it has been difficult to make definite conclusions. However, everything points to the Olympus in-body image stabiliser (IBIS). I cannot think of anything else that could cause this. IBIS-controlled sensor is the only moving part in the equation. Unfortunately IBIS info is not stored in image metadata so I cannot see which photos have had IBIS off but obviously it is almost always on because it is very effective.
I have tried to do some test shots comparing IBIS on and off, and I have not been able to see the issue when IBIS is off. But I also cannot see the issue clearly when I want to show it even though it has appeared often in my images, making on/off comparison difficult. If it is an IBIS issue, things like shutter speed are very likely to have an effect on the occurrence and severity of the issue.
How severe is the issue? Are there any workarounds?
The severity depends on your requirements. If turning IBIS off removes the issue altogether (I am still not 100% sure it does), it is relatively easy workaround. However, turning it off also removes one huge benefit of these cameras. Moreover, do you always remember to turn it off when swapping lenses? All this does take away significant trust factor from the system – you need to remember to do “something” to ensure sharp images.
IBIS and manually set focal length
When using Laowa on E-M1 mark II, I have added manual lens information in the camera, including the focal length 7.5mm. This way the camera adds the lens name and focal length in image metadata but also uses this to set the focal length for the IBIS; normally all this info is transferred electrically between lens and camera but manual lenses do not transfer any data.
Therefore, one possibility for defective stabilisation is that the focal length is wrong. What if the actual focal length is for example 8mm instead of 7.5mm? 0.5mm sounds like tiny insignificant difference but relatively it is quite big error. Only Olympus engineers can answer what kind of error is enough to cause issues in the IBIS.
I did quick test taking video with Laowa lens but I did not see anything odd happening. After all, the shift is still quite small.
I find this issue very annoying. While there are workarounds, I certainly cannot say I find the system reliable after seeing the issues in numerous photos. It is a good example that if you really want to have a reliable system, it is best to stick with Olympus lenses on Olympus camera.
I hope I could get some replies from Olympus and/or Laowa to possibly confirm the issue, and maybe tell me the actual focal length of the lens that could help the IBIS. I would not hold my breath though. Nevertheless, even though I am not a professional I hate this kind of extra hassle and feeling of uncertainty. So instead of continuing my tests and trying to find the settings that reveal or hide the issue, I may just sell my Laowa and maybe buy the Olympus 7-14/2.8 Pro (or Panasonic 8-18) one day.