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X T1: Weird effect in video, manual focus


bc200

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Hello everybody,

I am aware that the X T-1 does not perform very well shooting video, but I am experiencing a strange effect that I have not seen described before. (I read about moire and the autofocus issues).

 

In sunny conditions, and on grass/in nature, when I film with manual focus with or without focus peaking highlighting enabled, it looks as if there is a 'shadow' where the focus peaking would have been seen in the viewfiender.  This 'shadow' moves as I manually change the focus back and forth.

 

Here are some examples shot with the XF 35 mm F1.4, with aperture set to 1.4:

 

All other settings (ISO, Shutter) set to auto, film simulation is standard, movie mode is Full HD 60fps.

I have tried changing those settings but it does not make a difference (as far as I can see).

 

The effect is less intruding with a lower aperture.

 

Have anyone else seen this?

(Could someone we bothered to go outside and try?)

Any comments are welcome.

 

Thanks,

B.

 

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  • 2 weeks later...

That's pretty crazy!  I've never noticed that.  But when I shoot video, I press the AF-L button to set my focus (as I usually use that to focus versus the shutter button) ... I then flip the focus mode to manual and then hit the record button.  I flip the focus mode to manual because if I leave the focus in Single (which I always use) and start to record video, the camera does some screwy refocus glitch and my focus is screwed up.  If I put the camera into manual focus mode after I have focused, it doesn't touch the focus setting when I start to record video.  This has produced good results for me.  Some times I have had to put the focus mode to Continuous and then I start video recording because I or my subject is moving.

 

I have on the odd time moved the focus ring on the lens while shooting video to readjust best I could when looking at the LCD.  I have never seen anything like your video shows ...but I usually am shooting video (must like my stills) between F1.4 and F4.

 

I wonder if the same happens with different lenses?  I have the same lens and not noticed it for the little bit of video I have shot with it.

 

I would try doing this test using the rear LCD and not the EVF.

 

I should mention that I shoot at 1080p 30fps because I have found for some reason that when at 60fps, I've had quality issues.  I stick with 1080p or 720p at 30fps and seem to have better quality.

Edited by Adam Woodhouse
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Yes, I tried with the 15-55 mm lens, with F2.8,  and I get the same effect, but not so visible as with the XF 35 mm with F1.4

I use the focus ring on the lens in the examples.

I will see if I can test using Continuous mode instead.

 

Thanks!

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Maybe also try other frame rates when at it and using the rear LCD and not the EVF (not that I think it should make any difference, but worth a try).

 

 

 

Yes, I tried with the 15-55 mm lens, with F2.8,  and I get the same effect, but not so visible as with the XF 35 mm with F1.4

I use the focus ring on the lens in the examples.

I will see if I can test using Continuous mode instead.

 

Thanks!

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Maybe also try other frame rates when at it and using the rear LCD and not the EVF (not that I think it should make any difference, but worth a try).

Yes, I tried other frame rates with the same result.  I get this also when not using the EVF.

 

I discussed the issue with the local Fujifilm representatives and at first they also said this was very weird, and they had not seen it before, but then they re-created the problem with their own X-T1, and after that they said that this is just how it is with this camera.

 

I find it very strange that this should be the case with all X-T1 cameras that have been produced. Would not this then be reported as a well known problem with the video function, like the issues with moiré and focusing? After all, the conditions when this happens are quite normal (sun, greenery, manual focus, other settings on automatic).

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I suggest filing a bug with Fujifilm

 

The camera has been sent to Fujifilm for service and this is their response:

"The phenomenon of jagged edges or what looks like focus peaking is a by-product of anti aliasing combined with movement and high contrast subjects."

 

So, according to them the effect is to be expected and there is nothing wrong with my camera.

(I honestly do not understand how their response explains what I see in my videos, but perhaps it makes sense to someone).

 

So, by posting here I hope for comments on whether or not it is correct that all X-T1 cameras have this effect when recording videos with the mentioned conditions as seen in the samples.

 

Thanks!

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I think you may have found a unique condition where just the right conditions in a scene shows a flaw in the video capture process.  

 

Since it may happen so rarely amongst XT1 owners and so few of that small sub-set would even give it a second thought ... you may be one of a select few ... world wide ... that looked into it.

 

If your local Fuji Rep could reproduce it on their camera, I'd consider it to be a quirk of the camera and put the issue to rest.  If it is a problem you can't live with, the XT1 is the wrong tool for you.

 

I rarely have to do video work for my clients but when I've had too ... I've been able to get by with the XT1 thus far.  But I know there may be scenes that I shoot where the video quality will be lower than I hoped for.  But I've managed.  And knowing some of the quirks and doing a work around has helped.  I'm anxious to have the XT2 so that the quirks I'm living with will then be a thing of the past (at least for me).

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Adam,

yes, I guess you are right about this.

I just can't see how the conditions or the way I use the camera is so unique.

And everyone who sees it initially says there must be something wrong with the camera.

 

I first saw the effect when making recordings for a video for a side-project.

If you are interested, the final video can be seen here:

 

I guess 'the effect' is only noticeable when you are aware of it (3-5 seconds into the video).

 

Thanks!

 

 

...

If your local Fuji Rep could reproduce it on their camera, I'd consider it to be a quirk of the camera and put the issue to rest.  If it is a problem you can't live with, the XT1 is the wrong tool for you.

...

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