New Fuji Lens and a Warning


Misty morning in the trees at the Roaches. Fuji XT2 + 16-55 lens.
Misty morning in the trees at the Roaches. Fuji XT2 + 16-55 lens.

If you are a regular reader of my blog, then you may well be aware of the problems I have experienced with my Fuji 55-200mm lens. Following some rather odd results, the lens was returned to Fuji back in November who couldn’t find any problems. Wex then returned it for a second time following a review of some test images as they agreed, there must be a fault.

The lens is still being inspected by Fuji but Wex have kindly allowed me to trade it in against another lens. This is a huge help as being without a good telephoto lens means I can’t use the Fuji kit properly and always end up taking a second camera with me. Thanks to the trade in I now have the Fuji 50-140 f/2.8 + 1.4x Teleconverter and this weekend was my first outing.

Unfortunately, the location we chose was very foggy and remained so for most of the day. The fog did lift to a certain level but generally it was too dense to use the new lens properly. I did however manage a few test shots of distant rocks which a group of climbers were scaling. I mounter the camera on my tripod and lined up the shot using both the lens and teleconverter. The conditions were still with no wind and I was using a cable release.

To my horror, when I zoomed in to check the image I could see a lot of camera shake and the image was blurred. I tried again and again but I couldn’t remove the shake. I then tried removing the teleconverter to see if it was the cause of the problem but it wasn’t. The results looked very much like those I experienced with the lens I had returned.

Below you can see one of the problem images. Notice how the shake isn’t consistent across the frame and some areas almost come into focus but don’t quite get there.

Example of problem image.
Example of problem image.

And a section at 100% magnification.

Section of poor image at 100% magnification
Section of poor image at 100% magnification

Then through trial and error I worked out the cause of the issue.  Take a look at the image below which was shot immediately after the image above. This time the image is pin sharp across the frame.

Good image
Good image

And again, a section of the image at 100% magnification.

Section of good image at 100% magnification.
Section of good image at 100% magnification.

The cause of the issue was the Lee 0.3 ND grad filter I was using. With the filter on the lens, the images were out of focus and appeared shaky. With the filter removed the images were crisp and sharp. I could repeat the result time and again with all my Lee filters.

What appears to be happening is that the filter is causing a problem for the autofocus mechanism in the XT2 and it continues to refocus as the shot is being taken. Later I turned off the autofocus and could focus manual to capture a pin sharp image. If I set the camera back to autofocus the problem occurred again. What I haven’t been able to work out is why I have only seen the issue with the telephoto lenses. My other lenses (10-24, 16-55 and 18-55) all work fine with my filters.

This is one to watch out for if you are a landscaper and use filters. I was also wondering if anyone else has experienced a similar issue?

14 thoughts on “New Fuji Lens and a Warning

Add yours

  1. If I am set up to use external filters (I.e. Not screw-in filters) I am usually on a tripod and using manual focus to make sure that I am focussed on the desired area in the picture.

  2. Very interesting discovery Robin & glad you got to the bottom of it. But still quite strange why only the zooms seem to be affected this way by the use of filters. Also do you think that the filters may have been a source of, or contributor to, some of the RAW conversion problems that you were having with Fuji X sensors?

    1. Hi Jed. The filters are definately not the source of RAW conversion problems. I can produce great results now with Adobe although the best results still come from RAW Therapee in terms of outright image quality. I have been wondering if the filters are causing some form of reflection which is causing the autofocus to have issues. Both my Lee 100mm and Lee Seven 5 filters cause the issue. I must try it with some old HiTech filters when I have time.

    1. Thank you, it was a great day and I intend to return again in the future. Hopefully I can share some more shots. And regarding the problem, I’m delighted I worked out what it was. It’s cost me money trading in what is probably a perfectly good lens, but I now have an amazing lens and some very useful information to share. In my book, that’s a result.

  3. Thanks for your Expierence.
    I shot a couple of pictures with the 50-140 and Lee75 GND in AF and had no problems. But i used the X-T1.
    I already got the X-T2, but haven’t made any Pictures with that setup.

  4. Hi Robin

    a pro landscape photographer I know had similar issues with some (not all) his Lee filters and his Sony A7 (not sure which lens/es). He discussed it with Lee who asked him to check if his filters were perfectly flat. They were not – very slightly curved – and Lee replaced them for him. He considers it may have been due to them being stored incorrectly, under pressure from other items in his bag, which he leaves packed ready for action. He now ensures that doesn’t happen, as apparently it is a known problem.

    The depth of focus, i.e. at the sensor level rather than depth of field at the subject, is much smaller with long focal length lenses versus wide angles. This may account for why you have only noticed the effect with the longer zoom lens.

    Nigel

    1. Thanks, I hadn’t heard of this problem with the filters. I checked mine and they are all perfectly flat. I also don’t have this problem when using them with the Olympus EM5 and 40-150mm lens or the Canon 70-300 on a Sony A7R. I still think its related to the auto focus. I have a friend who uses glass filters and next time I’m out with him I will give those a try. Thanks again for the info.

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