Flashing Pixels!!

[Daniel Vesen]

Hi,

I've had a big problem with my GEMINI for many weeks now and RED does not really care about that and puts me off waiting for future firmware updates, which may come at some point, maybe never. I do not know what to do anymore. I have specially bought a low-light camera and can not use this in good conscience not in the low-light area. What a nonsense RED !!!!
What do I buy this camera for ??? !!!

The problem manifests itself in darker areas of the image by pixels, which flash in ever new places only for a frame. Estimated 5-10 per frame. This can NOT be compensated with a Calibration Map. The pixels are never permanently in the same place.

Of course you will not see these pixels as well on normally exposed images, but as soon as there are dark areas, you will notice that. I noticed it immediately after the purchase in the first low-light test. Even on the camera display !!!!
Here is demo material to view: http://transfer.captainmedia.de/Kb1P9HN

Am I too much too? Can not I expect a normal trouble-free picture for just under € 30000 ????
What a scrap !!!!

I reported the problem to my dealer. He also examined his demo Geminis. And behold - they have that too! Coincidence?? Three cameras with the same problem? Who else has this problem?

What should I say to my customers ??
Oh, a few flashing pixels is not that bad! To fix this in hindsight is really a detention of many weeks!

What now???

 

[Homer Dulu]

I downloaded the RAW, did a playback, but I'm not seeing what you're seeing? I see some small flashes in the sky, which to me seem more like stars or satellites.

I even exported to ProRes 4444 in 4K to make sure my computer wasn't doing some funky debayer and I'm not seeing anything out of the ordinary either. Scrubbing through it slowly even makes it more definite that these are points of light in the sky, not flashing pixels. Even tried upping the ISO to 6400, but the noise is more distracting at this point. If anything, I feel like that a noise reduction pass in something like Neat Video would eradicate that problem completely.

It's been said multiple times on this forum that the Gemini is very good for low-light, but not *extreme* low light. And even then, it seems like most people still use a spot of noise reduction. Using a light meter, what readings were you getting? For that type of shooting, perhaps you would have been better off buying an A7S II or GH5s. I'm not sure this is a camera issue at all.

 

[Homer Dulu]

This is what I'm seeing - the forum's resizing it so it's a bit hard to see. But doesn't look like flashing pixels to me. Otherwise they would be really bright white and obvious to see.

 

[Alan Greene]

I'm seeing it, in the sky near the top of the frame. It's definitely not noise, and too sharp to be a celestial body (and too fleeting, a single frame). There are some larger spots that come and go, and those must be some light sources that are flashing. The problem pixels do really seem to be just a single pixel.

Here's a clip cropped to the area in the sky that I'm looking at. The issue is quite obvious, even when playing at full speed. https://cl.ly/dde75e7255d6

And I don't have Neat Video, but for what it's worth, the noise reduction in FCP actually cleans up the noise and preserves those flashing pixels. https://cl.ly/2c31dd375934

 

[Karim D. Ghantous]

That certainly looks like a faulty sensor to me.

 

[Homer Dulu]

I'm seeing it, in the sky near the top of the frame. It's definitely not noise, and too sharp to be a celestial body (and too fleeting, a single frame). There are some larger spots that come and go, and those must be some light sources that are flashing. The problem pixels do really seem to be just a single pixel.

Here's a clip cropped to the area in the sky that I'm looking at. The issue is quite obvious, even when playing at full speed. https://cl.ly/dde75e7255d6

And I don't have Neat Video, but for what it's worth, the noise reduction in FCP actually cleans up the noise and preserves those flashing pixels. https://cl.ly/2c31dd375934

Ah okay I see it now. Yikes.

Daniel, I'd advise to open a support ticket with RED.

 

[Alan Greene]

Any update on this? I'm curious to know if there has been any progress.

 

[jordan levy]

cant you just return the camera if you just bought it?

 

[John Marchant]

That looks a lot like cosmic radiation hits. They'll appear on all highly sensitive cameras, but are usually missed because noise reduction on most stills systems hides it. You can observe them on just about any CMOS or CCD sensor though.

I documented seeing these on the original Monochrome, which was the first camera I'd seen sensitive enough to show them easily, but at the same time not using any in camera NR to hide them. If you go looking for them you'll find them on any red camera, but also on any good DSLR if you run long exposures with NR.. The tricky part is that the ionizing radiation that causes it is very unpredictable and variable. When I first noticed it I was getting multiple hits per second, but when I went to repeat it I was waiting minutes in between.

The most obvious ones are the rarest, where the energetic particle hits across the plane of the sensor, and you get a streak or bounce rather than just a single pixel.

http://kippertie.com/red/monoflashes/ <- very old link...

 

[Jordy Vandeput]

Hey Daniel,

I'm experiencing the exact same thing! Colored flashing pixels and way too much ugly digital noise.
I'm also in contact with RED, but it takes forever. They did managed to make a specific version of CINE-X for me which resolved the flashing pixels. But that's not a solution as I don't use CINE-X to edit..

As for the noise, first they say it doesn't look normal and now they say I exposed my shots wrong. But a lens cap shot at ISO 800 shouldn't look like pixel paradise.

Next week I'll be able to do some side by side tests with a Gemini that does work like it should. Hopefully I can show RED that they need to take my unit back.

 

[Tommaso Alvisi]

They did managed to make a specific version of CINE-X for me which resolved the flashing pixels. But that's not a solution as I don't use CINE-X to edit.

Totally agree...this is not a solution...

How they justified the need for a modified RCX version if the camera has nothing wrong??????

 

[Jon Dishler]

That looks a lot like cosmic radiation hits. They'll appear on all highly sensitive cameras, but are usually missed because noise reduction on most stills systems hides it. You can observe them on just about any CMOS or CCD sensor though.

I documented seeing these on the original Monochrome, which was the first camera I'd seen sensitive enough to show them easily, but at the same time not using any in camera NR to hide them. If you go looking for them you'll find them on any red camera, but also on any good DSLR if you run long exposures with NR.. The tricky part is that the ionizing radiation that causes it is very unpredictable and variable. When I first noticed it I was getting multiple hits per second, but when I went to repeat it I was waiting minutes in between.

The most obvious ones are the rarest, where the energetic particle hits across the plane of the sensor, and you get a streak or bounce rather than just a single pixel.

http://kippertie.com/red/monoflashes/ <- very old link...

This makes total sense, the Gemini being the most sensitive sensor of the Red lineup, and originally developed for astro observation, it would also be most likely to show these radiation hits. Fascinating actually. I found this of interest, "The sunspot cycle and Cosmic Rays…. There is a well-known anti-correlation between times of sunspot maxima and times of maximum cosmic ray detections at ground stations. This relationship is now understood to be due to the solar magnetic field providing more shielding to the inner solar system at sunspot maximum, so that fewer cosmic rays reach earth." Combined with this, "March 5, 2018: Cosmic rays are bad–and they’re getting worse.

That’s the conclusion of a new paper just published in the research journal Space Weather. The authors, led by Prof. Nathan Schwadron of the University of New Hampshire, show that radiation from deep space is dangerous and intensifying faster than previously expected." https://spaceweatherarchive.com/2018/03/05/the-worsening-cosmic-ray-situation/

The conclusion of this paper is, "The problem is, as the authors note in their new paper, the shield is weakening: “Over the last decade, the solar wind has exhibited low densities and magnetic field strengths, representing anomalous states that have never been observed during the Space Age. As a result of this remarkably weak solar activity, we have also observed the highest fluxes of cosmic rays.”

Therefore, not surprised that a very low light camera could be contaminated by such a phenomenon.

 

[Mike Gialloreto]

Reviving this thread - I just bought a used Gemini and would love to know if this is considered "normal" at this point. It's not cosmic radiation in my case as I've tested with the port cap on in a basement.

The strange part is the dancing pixels completely disappear in Redcine and Resolve when set to the highest decode settings. Maybe this wasn't the case at the time this thread was active. This leads me to believe that it's a known issue that has been fixed in software. However, they still show up no matter what if you shoot ProRes in camera, which is frustrating.

Any Gemini owners care to test? Port cap, 3200LL, ProRes or anything less than "full res premium" decode in Resolve will show it. Thanks!

Edit: I can see them live in my monitor as well.

Edit 2: Got a response from red, it's normal and corrected in software. Will still show in ProRes. Sorry if this is known information at this point.

"As this artifact is inherent to CMOS sensor technology, replacing cameras or sensors with new ones is not the solution. In order to help minimize the appearance of flashing pixels, RED deployed a tunable solution in April 2019 for REDCINE-X PRO and for RED’s SDK so other NLEs like DaVinci Resolve could implement it."