Weirdest lens issue I've ever seen - Fuji 150-600

This is going to sound really weird, but hear me out. My image quality is being affected by my camera/len's orienation!

-Fujifilm Fujinon XF150-600mmF5.6-8 R LM OIS WR Lens
-Fujifilm X-T5 (latest firmware)

I've attached two sets of images to display the issue I am experiencing. The first is a shot of a far away building and the second is a shot of a manual with small text. Both shots were performed at 150mm with OIS off.

Both pairs of images were taken with the camera oriented vertically, but rotated 180 degrees from each other. One image has the shutter button on top of the camera and the second image was with the camera rotated 180 degrees with the shutter button on the bottom.

What you will see is that for "button up" shots there are some optical issues. The building lights show smearing and the text shows a lack of sharpness.

I've checked and rechecked everything. OIS off, 2 second timer release, rechecked focus, ensure no camera movement or vibration, etc. This is not unique to a particular corner of the sensor. If I recompose the images to a different corner, the behavior is the same.

My theory is that this is some sort of issue with the OIS system in the lens. When I rotate the camera I am using the lens collar so the lens and camera are turning together as a single unit. Even with OIS turned off, the system still manages the stabilized elements to keep them fixed in place. I think something might be drifting a little in specific orientations either due to gravity or input from the cameras gyroscope. You can hear when the lens makes adjustments in a quiet environment and I can hear it make noise when I slowly rotate the camera.

I think my lens is still under warranty so I could send it in, but this issue is difficult to communicate so I'm hoping I'm making sense here. Not sure if anyone has seen anything like this before.

Please clarify: You say, "The first image of each set has the shutter button on top..." yet on my screen, the first image of each set is named "button_down."

The issue is apparent in both "button_up" photos, and I think it should be investigated by Fuji as a potential warranty issue.

runswithsizzers said:

Please clarify: You say, "The first image of each set has the shutter button on top..." yet on my screen, the first image of each set is named "button_down."

The issue is apparent in both "button_up" photos, and I think it should be investigated by Fuji as a potential warranty issue.

Click to expand...

Looks like Photrio reordered my photos alphabetically. I changed the language to make it less confusing.

you might want to look for a test chart/resolution chart ( https://www.graphics.cornell.edu/~westin/misc/ISO_12233-reschart.pdf ), and photograph it under good lighting filling the frame. Ideally it could help determine if the issue if visible in a limited amount of the frame and if it moves to somewhere you didn't see it when you invert the camera. I've has some lenses that have things moving around inside when the lens isn't powered. I'm wondering if an element is moving out of place when right side up?

Are these 100% crops from the entire frame? Can you post the fill frame of each and show where you took the crops from? It's possible that one corner of your lens performs differently from another. The difference is slight.

koraks said:

Are these 100% crops from the entire frame? Can you post the fill frame of each and show where you took the crops from? It's possible that one corner of your lens performs differently from another. The difference is slight.

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I performed the same test in all corners and the center. The results are the same no matter the corner.

abruzzi said:

you might want to look for a test chart/resolution chart ( https://www.graphics.cornell.edu/~westin/misc/ISO_12233-reschart.pdf ), and photograph it under good lighting filling the frame. Ideally it could help determine if the issue if visible in a limited amount of the frame and if it moves to somewhere you didn't see it when you invert the camera. I've has some lenses that have things moving around inside when the lens isn't powered. I'm wondering if an element is moving out of place when right side up?

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Thanks for sending that along. I'll end up re-shooting with the chart later. Might help with communicating the issue with Fuji

I think this rather is a focusing problem. Looking at both pictures of the houses, i find the grey building in the foreground to be slightly sharper on button down - while the dark building in the background is a little less sharp, if you look at the white balconies. Button up the grey building is a little less sharp, while the balconies are a tad more sharp. Looks like the auto-focus is acting a little different when the camera is rotated.

cirwin2010 said:

I performed the same test in all corners and the center. The results are the same no matter the corner.

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Ok, good job on checking systematically. Very odd. Maybe @Harry Callahan is right and it's a focus issue after all. Then again, I can see how such an issue might be introduced by a slight bug in the stabilization function.

What are the results when you make these pictures with OIS=ON?

forest bagger said:

What are the results when you make these pictures with OIS=ON?

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The results are the same from my testing.

cirwin2010 said:

The results are the same from my testing.

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Does the OIS work corretly also?
If not, the OIS lens is tilted.

forest bagger said:

Does the OIS work corretly also?
If not, the OIS lens is tilted.

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OIS certainly stabilizes the image so I assume it is working properly.


Turns out the US only gets 1 year of warranty so that sucks. I'll probably have to looks at repair options. I did retest the lens with the above mentioned test chart and reconfirmed the issue. Softness occurs across the whole frame when in the vertical button side up position. And I've confirmed it is not an issue with focus by both performing repeated manual and autofocus shots. The issue is somewhat less pronounced when zoomed in from 150mm, but it is still there. I did limited testing at other focal lengths. Stopping down also reduces the issue to a point until diffraction takes over.