FS7: Dead Pixel and Chromatic Abberation?

S

Soldier

Well-known member
I'm having a couple of issues with the FS7. We recently bought one for work, and I've been doing a few tests with it before using on a job.

1. The first issue is a dead or stuck pixel - looks to be a group of pixels maybe - which is really distracting. It sometimes looks blue and other times it looks purple. it is very noticeable in UHD at 100%, especially on black backgrounds. I've attached a couple of zoomed in screengrabs. Low Rez, but you get the idea. Is there any way to fix this in camera? sensor cleaning?

2. When shooting in XAVC-I I noticed some pretty hideous chromatic abberation in fine detail with high contrast. I tried a few different lenses nikkor AI-S 35, Metabones with Canon 24-105, Tamron 24-70, and a Rokinon 50mm, and it was present in all of them (apperture at f/11). I've attached a couple of zoomed in grabs of the type of noise I'm dealing with. To be honest, in 10 years I haven't seen anything quite as bad. Has anybody experienced anything similar?

Thanks in advance,
Glen
 

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Can't help re the pixels - suggest you speak with Sony support. I'm assuming you've run the ABB routine - it nags you to do so every few days or so.

Re the CA, I experienced similar CA with a Canon 24-105/Metabones Ultra combo - I concluded it was the limitations of my particular lens and I've since given up on using a Metabones speedbooster.

However, others are using the Metabones quite happily - or at least they were when I raised the same issue in a thread a few months back.

For me, the MB Speedbooster isn't the free lunch I thought/hoped it was. It introduces a whole load of variables into your optical path. Fantastic at times, maybe, but a PITA on certain shots.

I gave up and returned it.

Ben.
 
To clafiy what ben said - Black Balance.

Is the CA in HFR mode (above 72FPS)? If so that is what it looks like.. fine for web video but not really broadcast or cinema standard.

S
 
To clarify what Ben and Sam have said, it's actually the APR command that you want to execute. Black Balancing may catch pixel problems but that's not it's primary purpose. APR's only function is to fix problems like this, and that's why the camera reminds us every 5 days or so. Hopefully that will fix it.
 
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I think it's the combination of certain lenses and certain metabones adaptors as some don't have an issue. Probably alignment. I saw when Sam raised the issue so I checked mine as soon as it arrived. Pixel peeping at mine only resulted in a sigh of relief instead of a cringe. since its occurring with several lenses I believe its your adapter.
 
Regarding CA I'm sure you want an in-camera fix but CA can he dealt with in post if it's bad enough and you want to fix it.
 
Thank you for your responses.

1. I've solved the stuck pixel issue by black balancing. Thank you!

2. I'll do a few more tests to further investigate the chromatic aberration. The consensus seems to be that it is probably an issue with the metabones adaptor. It certainly seems worse when using EF mount glass, but I've also noticed it when using my Nikkor AI-S glass with an e-mount to nikon dumb adaptor.
 
Soldier said:
Thanks, Doug. I didn't actually know about this function. The camera hasn't warned me about it, though I only have about 20 hours on it so far, so the warning message will no doubt pop up in the future.
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I think APR is about the first thing that comes on when you first boot up. If you skipped it that's why you had the pixel.
 
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The CA seemed barely there with the metabones and Canon lens. I fact it looked more like jpg artifact from the capture. But online uploads often have compressio issues.
 
some chromatic aberration ( usually longitudinal green/magenta) is actually present in almost all still lenses though I see that more often at open apertures. The Canon 24-105 is pretty notorious for CA, but the Tamron should be much cleaner. I would get a metabones adapter without the speed booster to test without that extra glass.
 
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