Sensor reflection/ghost images

Come on, it´s not THAT bad.

I shot this against huge shop windows, with a ton of fluorescent ceiling lights and even a welding torch.
And that mostly on a vintage Vivitar lens - that is super prone to flare and ghosts - without any sunhood or matebox.


Ghosts pop up only at certain angles - if you see them, move a bit and they go away.

Frank
 
I've NEVER seen it as bad as the OP, ever. That's why I think Sony should look at the camera. The times I have seen it, it's been pretty slight and easy to work around. Maybe it's the color of it that is so off-putting compared to other reflections. Mine are always green.
 
danstone said:
http://www.youtube.com/watch?v=Q7ymGLcbq8A&

Most of the scenes in the clip above would be impossible for the FS100. Ben standing in front of those airport windows, the bright plane windows and the ceiling lights in the airplane. I can't even film fluorescent ceiling lights without getting reflections.
Click to expand...

There would have been masses of fill in the airport, the outside isn't over exposed.

I've just done some tests with bright candles in low light, one of the reasons was to look for this specifically. So very bright spots of light, clipped yet i detect just the slightest flare that frankly no one would see and i think it might just be flare - not sensor reflections.

I reckon you should call sony support up, get a swap, bring it to them to see. I think you're seeing this way more than the rest of us, so have hope - it might just need a swap out

cheers
Paul
 
paulcurtis said:
I've just done some tests with bright candles in low light, one of the reasons was to look for this specifically. So very bright spots of light, clipped yet i detect just the slightest flare that frankly no one would see and i think it might just be flare - not sensor reflections.

I reckon you should call sony support up, get a swap, bring it to them to see. I think you're seeing this way more than the rest of us, so have hope - it might just need a swap out

cheers
Paul
Click to expand...

I also don't see these reflections to this degree or without an ND filter....
EDIT: Well, I'm seeing it everywhere now. I even found some older footage where we must have just passed it off as flares. Support ticket opened with Sony.
 
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Just to bring this up again. I don't know how many UK folk here are watching the new Upstairs Downstairs which is an Alexa show but the sensor reflections in it are insane, all over the place. Green windows and everything.

Looking at the technical details, they shot on all the normal stuff, Alexa, Master Primes etc,. just perhaps i'm now so aware of them i notice them more.

cheers
Paul
 
Postmaster said:
By the way, have you guys noticed, that the ghosts are flipped upside down and also horizontal?
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Green ghosting is reflected through the center of the image. Left becomes right, bottom becomes top.
And I think i've seen it on 5D too. The reason why we didn't noticed it so long is that we thought that it is lens flare or it was hidden in the flare.
 
Any good Lens Flare plugin comes with 35mm presets which recreate what you're seeing.

https://vimeo.com/25666605

It seems to be very dependent on lens, adapter and angle to the light as I have only seen it once an most flares I have seen are reasonably pleasing. Maybe the OP had the perfect storm for the reflection to look so strong.

Edit:
Testing my Novoflex and Nikon 500 1.8 I pointed it at the bright window and recreated the reflection. The window was way over exposed but I got the flipped image. Stopping down slightly from max aperture cleared the reflection but the window was still way over exposed.

Too much light is hitting the sensor and has nowhere else to go but back onto the rear lens elements. Probably something you get a feel for with more experience with your lenses.

Edit2.
Aperture affects the reflection much more than the Fader ND i.e I have to add more ND to clear the reflection than slightly stopping down.

Hope that bit of info helps.
 
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Hehe, yeah, it's weird. Sometimes I get it and it's really hard to get rid of it, but most times, I never see it. I've not figured out the exact combination (lens being consistent) that is causing it for me. Every time I think I understand it and then expect it, it's not there!
 
Postmaster said:
If I bolt the same lens/filter combination on my 5D, there is no ghosting at all.
It´s the FS100 - sad but true.
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I hate to brake it to you but 5D does it too. The blue reflection under the window and to the right are the window bars reflected. I guess it is natural with all digital sensors just as is fringing with super wide apertures. Digital sensors still have many flaws.

Ar9q7UICIAAONbG.jpg
 
But I see this on movies shot with film as well, in fact, just a few nights ago I was watching some really old horror films and there were reflections as well. I'm sure many times it is the layers of glass, it's just with the FS100, the sensor reflects quite a bit. They need a better layer on the front of it that isn't so reflective.
 
Yep, it happens on film too. Just watched "Sorcerer" from 1977, it has it. Seen it in episodes of film-shot TV shows. It's more prevalent on the FS100 (and AF100) than on film, but it does definitely happen on film -- and the F3, and the Red, and will almost certainly happen on the BMC and the FS700 too.
 
Just saw it in Supernaturals - and I mean: fat a.. reflections all over some scenes.
Once you saw it, you start seeing it everywhere.

Frank
 
Yep, never noticed it as much before. I think one difference is the AF/FS100 have a green tint which for me makes it pop more.
 
Yeah, I just shot something with the Scarlet last week and noticed similar reflections. They weren't nearly as bad as my FS100, which actually shows features of people's faces being reflected, but they were there.

On a side note, the Scarlet was such a pain on set that I almost switched it out for the FS100 - and that's saying a lot.
 
I just watched the Abel Cine FS700 low light test as I'm interested in this camera.

http://resources.abelcine.com/2012/...ht-performance-dynamic-range-and-slow-motion/

The FIRST thing I noticed on the candle light test is how much stronger the internal reflection of the candle flame is on the FS100. It's plain as day and dancing like crazy. On the FS700, you can see it, but it's much fainter; which is obviously a good thing.

With that said, it looks like on the FS100, there is only 1 internal reflection of the candle, but on the FS700, it looks like there are multiple reflections of the candle, but they could almost pass as a lens flare.

I also watched several other FS-700 videos that were shot into direct light sources and the sun, and I didn't seem to notice it. It might be there, but not so obvious

http://vimeo.com/41848612

http://vimeo.com/39888828

This dancer / drummer video, I can't really tell, but on the Dancer there is some weird reflection, but not sure if it's internal, at least I can't see her face as a reflection.

http://vimeo.com/39405035
 
Gentlemen, I was investigating that ghost problem and I think I got to the bottom (and may even have a cure).

I was looking into IR cut filters lately and - as you may know - there are two types.
One type is absorbing IR, the other type - called hot mirror - is bouncing it off.

I think that´s exactly what happens here.
The FS100 has a hot mirror in front of the sensor, it´s bouncing light back and forth between the glass of the lens.
It´s the same effect, that you can provoke, if you put a 4x4 hat mirror as a last filter in the mattebox and stack - let´s say an ND and pola in front of it.
But it goes away, if you stack the hot mirror as first filter and the rest behind it, towards the lens.

This is all sheer theory (brain fart, as we say in Germany) from reading into that matter in the moment, since I can validate it, when my hot mirror arrives (hope tomorrow).

If it works as I think and hope, we solve a really annoying problem and get better red handling.
That´s an other thing I came across, while doing my research. By using vari ND filters (and maybe even normal ND filters) you increase the amount of IR coming in (actually you decrease everything but IR).
That means our red channel problem might be also solved with an IR cut filter.

I ordered an Heliopan UV/IR cut filter, but found not the best reviews on the web.
But there is also Rosco, Schneider, Tiffen, B&H and a few others.

Frank
 
Came to the same conclusion on IR filtering, as I did mention before to you Frank. I'm not sure why I totally forgot that EVERY camera needs IR filter, but it's absolutely changed the way my images come out even on my toy camera (Gh2).

You should throw up some examples in a different thread.

I'll probably do the same for GH stuff.

Good investigating on the Hot Mirror deal.

Oh, additionally: you CAN use an IR ND on top of a Fader, but the color cast after white balance may not be very desirable. I still can't tell if I like it or not, but it's helpful... I mean I think. lol
 
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