Black noise

[RivaiC]

Hi guys

I have seen quite a lot of snowy like (vertical stripe) noise in the black area of epic. It happens quite frequently with epic footage as compare to red.

Everything is well lit, outdoor iso800, 8:1 compression. Yet this noise stripe pattern is very clear. Are we supposed to do black shading everytime like this ?

It is relly takes a while and we dont know if it will success

Any experience on this problem? And how to solve it

Rivai

 

[Evin Grant]

What are you viewing on? Is this seen in realtime off a redrocket or just at 1/8 res playback?
I've found the camera very clean up to 2000 ISO, not balck problems at all.

 

[RivaiC]

Viewing on redcine-x full encode. Try to export out to dpx. Same problem. At first i thought is the result of scale viewing. Zoom in at 100% is very clear of the noise pattern, snowy like. Software encoding.

Actually i notice this since day one. But after several shoot, i couldnt figure out what is the problems.

 

[Glen David Miller]

Hello. There is of course 1000 things that could be happening (Bad media at that memory location, a recording glitch, on the Red One, if the camera got too hot, the image could show signs of noise like you've written about), but the real questions: Is it on one take or all the shots from the day, and is this the first time you've had this problem, or is it a repeatable issue?

-Glen

 

[Ryan De Franco]

Evin... it's very interesting that you and others report "very clean up to 2,000 ISO," while I and others find our MX Scarlets unacceptable at ISO 800. I very much enjoy my ISO 320 camera, but the noise at 800--even right after a blackshade in decent environments with an even histogram--is like not at all like the Red One and Epics I've used with the "same" sensor.

Thankfully the noise has a nice structure and frequency, but it's always there. It sounds like Rivai is talking about both "snowy" noise and a noise "stripe" pattern... the stripe I haven't encountered, the wash of grain like noise I get every time I rate at 800...

R

 

[RivaiC]

Glen, it is a repeatable issue. It is there since day one

However, you are right. The weather is hot, VERY hot. If that is the cause what shall we do ? Compress the camera with liquid cooling ?

It happened mostly on outdoor. Rate 800


Rivai

 

[Les C.]

Evin... it's very interesting that you and others report "very clean up to 2,000 ISO," while I and others find our MX Scarlets unacceptable at ISO 800. I very much enjoy my ISO 320 camera, but the noise at 800--even right after a blackshade in decent environments with an even histogram--is like not at all like the Red One and Epics I've used with the "same" sensor.

Thankfully the noise has a nice structure and frequency, but it's always there. It sounds like Rivai is talking about both "snowy" noise and a noise "stripe" pattern... the stripe I haven't encountered, the wash of grain like noise I get every time I rate at 800...

R

Do you know anyone with an Epic where you could both shoot the identical scene using the same lens at the same time?

I'd heard such great things about the MX sensor at 2000, even with the older RED using the older electronics. I watched the Skyline movie shot with RED One/MX, with a lot at 2000 - and it looked great (at least to me).

This looks like something to document one way or the other - as I'm sure counting on better than what you describe?

 

[Panos Bournias]

Rivai, maybe outdoor when too hot change the fan speed to keep it cooling while recording. We have not experienced disturbing noise,
only when 300 frames 2K if not enough lights and shutter at 180 deg. Or maybe again let it warm up as when in location and do a black calibr. when temp in camera is up to 39-40 C maybe.
You will go over this I am sure.

 

[Glen David Miller]

Rivai,

During the times I've seen this problem, a few things seemed to help... The worst of which was allowing the camera to cool down for a little while between takes. On the Red One, sometimes the lower vents could be blocked and allowed heat to build up. If you're not recording audio, crank the fans!! (I wonder if blowing cool air from a hair dryer into the entry vents between takes would be too much?)

I would ask one of the engineers at RED about this last idea before you do it, but, in worst case situations, you could see if securing a few "Peltier plates" to the body might cool off the inside a little (making sure not to touch the HOT side), or go back to the old mitchell days and blimp the camera in an electric cooler. As long as condensation doesn't start forming. Yeah, ask someone about that first!! SURE, that sounds nuts, but, film making is sometimes an exercise in insanity, no? And sometimes you have to keep shooting.


-G