Vertical lines in high ASA

[Dj Joofa]

JBeale,

You are right, such correction can be done in post also. When we were looking at such stuff we really wanted to know why such things happen on the sensor. We really went quite deep, for e.g., even trying to figure out why would certain lines turn a certain color, and gained a lot of experience.

 

[zak forrest]

Is that what happens at high ASA in low light situations? I gotta tell ya, the footage Zak posted looks terrible!!

Ricardo, RED KICKS ASS IN LOW LIGHT.

You shouldn't take that clip as an example AT ALL.

That was an extreme example, it was from a low resolution proxy that was super boosted.

When color corrected and rendered out in RedCine it looks much better. But still that vertical stuff should be remedied, I hope they do that. I personally welcome noise, it doesnt bother me if done a certain way within a certain aesthetic depending on the picture.

That clip I posted is an odd shot you know? Not the greatest example, and certainly not normal. For example:

Here are stills from that same scene, rendered out properly:

{These arent looking the way they look in photoshop in this browser.. maybe download these and look at them in photoshop...}

 

[Steen Linde]

I have seen this too in my pictures and this was shot in ASA 320. The amount of noise is less but it has the same nature like the high ASA noise.
On a normal shot in daylight I could see the noise in all the black and dark grey parts of the picture. I did a Black shade calibration (caps on and t.stop22) and the camera was OK ( it told me). I still had the same problem. The preview output was noisy. I did a test render in Redcine/Red Alert and it was noisy. When I took the footage into Scratch the noise was gone.
The footage was recorded in Build 14.

Cheers

 

[zak forrest]

Okay, I just rendered out the same shot of Ellaree's face (the noisy quicktime I posted earlier which was from a proxy.)

Here is a link to the ProRes quicktime and an h264 of the same clilp but properly rendered out of Redcine-FULL

http://www.zf-films.com/mov/hamptonnoise

As you can see, noise turns nearly invisible. Nothing some post can't fix. But this is also because the scene is dark, and I made it dark in Redcine. It's supposed to be in a dark room with a lamp 30 feet away with a T-Shirt over the lampshade. The old "make it dark" trick might not work in other noiser situations, so I DO hope they fix the vertical noise problem eventually. And a heads up would be sweet, so I could plan the rest of my shoot around it and make sure all those scenes are shot on the nicer build... :clown2:

My apologies to Red for posting an image that doesn't do the camera justice.. I should have posted these first, but it IS kind of interesting to see the difference between the proxies and the final thing right?


{ if you watch these in your browser instead of downloading, they will be too bright, and possibly noisy. Watch them in quicktime player with the final cut color compatibility box checked in the preferences... which is also interesting, because you could get an idea of what the noise would look like after a full debayer in redcine when it isn't being color corrected to look extra dark like my scene... :shifty:

 

[Deanan]

Very typical behavior. It might not be surprising if you start seeing magenta and reddish lines. Calibration is missing stuff, as I have said before.

Joofa, since you have a good amount of technical knowledge please don't mislead people with assumptions or generalizations that are incorrect. The blue lines being referred to is a connector/cable problem that was easily corrected and have nothing to do with calibration.

 

[Ricardo Mehedff]

Zak, i see what you mean, the ProRes clip looks better, even though i still think it shows alot of noise... and i agree that the vertical noise/lines are a problem that really should be looked at.

 

[SF Geek]

Hey Zak,
If I turn on the final cut studio compatibility button, I can't really make out what I'm seeing. The noise is still there it's just darkened to such a degree that it can't be seen, and to my eye the image is also too dark to be seen.

I would really like Red to comment on this thread, more than just do a black shading. Is it something that can be fixed in time? Is this something that can be fixed with more elaborate calibration or is it a processing issue?

 

[SF Geek]

Deanan,
What is the case with the vertical lines that are not colored and are visible in all red cameras?

 

[Dj Joofa]

Joofa, since you have a good amount of technical knowledge please don't mislead people with assumptions or generalizations that are incorrect. The blue lines being referred to is a connector/cable problem that was easily corrected and have nothing to do with calibration.

Sorry Deanan, I fully agree with you. I should not have jumped to conclusions as it is as you say a cable problem. This had all the hallmarks of that notorious sensor aggravated line problem that is just the bane of sensors.

But you are right it is my mistake.

 

[SF Geek]

Wow, this thread got moved to the graveyard.