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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Black shade temprature experiment.

Timur Civan

Timur Civan

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I got a "excellent" black shade on my epic right now. Grainless.

It was a bit of an accident really. I had set the camera to be at 40% fan for an interview the day before, and the interviewer requested the camera remain quiet when the camera cut, so I set the standby fan to 40 as well. Next morning I black shaded the camera with the standby speed still at 40% after a 30 min warmup period.

The epic was running at about 42/63 on the temperature meter. When it was done I noticed the fan was set low, and returned it to 45running, 70 standby. The camera returned to a more normal 38/57 temperature reading. However, the image was amazing.

Try it for your selves. Seems that black shading warmer then operating cooler helps keep the noise signature lower.

Shot a ton at 1600-2500 ISO with little grain. Will post some footage when I get home.

Anyone want to try it and see if the results work for you too?
 
that sounds awesome.
i hope this is not a myth and proves to be scientifically accurate.
i hope some RED team could elaborate on this.
 
May as well post a .r3d (still or motion), as it'd be very difficult to tell via compressed web video... Or so I'd imagine. I need to blackshade soon anyway, so I'll definitely check this out.
 
Wow - you shoot with the fan at 40%?
No wonder sound people hate Epic!
so far I have been running the camera at 70% standby and 25% when recording and it is silent during takes.
This is for drama in a studio environment where takes rarely last longer than 2 minutes.
I'll try blackshading while the camera is warm.
 
I'm gonna go try this right now and see what happens.
 
40 if you intend to keep the fan on constant. It's actually less disruptive than hearing the fan blower between takes.

nigelsmith said:
Wow - you shoot with the fan at 40%?
No wonder sound people hate Epic!
so far I have been running the camera at 70% standby and 25% when recording and it is silent during takes.
This is for drama in a studio environment where takes rarely last longer than 2 minutes.
I'll try blackshading while the camera is warm.
Click to expand...
 
Bob Gundu said:
40 if you intend to keep the fan on constant. It's actually less disruptive than hearing the fan blower between takes.
Click to expand...
Might be less disruptive to crew, but we can't record good sync sound with it that high, especially on w/a close-ups, or in small interior locations.
 
Bob Gundu said:
40 if you intend to keep the fan on constant. It's actually less disruptive than hearing the fan blower between takes.
Click to expand...

Assuming that the ambient temps are moderate I agree that setting record and standby to the same rate can be less disruptive and depending on camera proximity might not even rile up the sound guy ;-)

Cheers - #19
 
Sensor temp is definitly influencing the black shading results. It's very important to perform it at targetted shooting temp.

Patrick
 
JanneJansson said:
Sounds stupid.
Click to expand...

Why does it sound stupid? I seem to recall months ago back when everyone was getting their Epics, someone from Red came on the board to offer advice regarding how to do an effective black shading, and one of the main things I recall him saying was that temperature does have a noticeable effect on the quality of the black shading... and to that end to allow the camera to warm up before doing it.

If Timur often shoots with his camera running between 42/63 degrees and he finally did a black shading at that temp, I would think the image would probably be cleaner. That said I would love to have an r3d frame to look at.
 
That's the way I remember it too.

Just finished doing the black shade at 66/70 temp. After camera cooled, I ran the iso up to 12,800 w/lens cap on. At new temp 36/49 the image is pretty clean but there is a red tint on the right side and to a lesser degree throughout the upper part of the screen and a green glow at the bottom of the touchscreen. Does this indicate light leakage during black shade?

BIG EDIT! I mispoke about temp. Should have read 46/70
 
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Update:

As the temp has climbed to 39/52, the red (or magenta as it appears to be) and the green glow have almost disappeared. There is some noise in the image but it is hardly noticeable.

This with cap on and iso still set at 12800, fan set to automatic.

Other info: right side camera brain registering 108.8 F... left side near SSD module, 100.7 F... Rear of brain 108.0 F, front of brain 95.0 F, ambient room temp ~ 90 F.

Of course there is noise, but it is small grained and doesn't jump out at you.
 
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I'm not saying its a miracle, im just saying Blackshading at a warmer temperature, then operating a bit cooler seems to help the noise a bit. The whole point is that i want so see what other folks are finding. The cooler the sensor, the less noise you will get, but My theory is that black shading at a higher temperature when the noise floor is higher, then cooling it down for operation, may help keep the sensor quiet.

I noticed that the performance was better because after the warm black shade, when i was making 1080 proxies, i was able to punch up the ISO a bit higher than normal, around 1600, and still get a reasonable low grain image.


Tonight im going to do the following:


B/S the cam Room temperature with fans at Standby 70% Shoot a fixed still life, with black, white, and some bold colors in shadow and light. This way we can see what the channels are doing.

B/S the cam Hotter, After 30 min of 40% standby FAN, B/S, then increase the fan to 70% standby allowing time for it to cool, then shoot the same shot.
 
With cap on after doing hot black shade and after camera warms up again after cool down, set iso at 12800. Once the tint has disappeared from the image (about 15 minutes on my camera) move the iso down step by step. On my screen iso 5000 looks like silk.
 
Elsie N said:
With cap on after doing hot black shade and after camera warms up again after cool down, set iso at 12800. Once the tint has disappeared from the image (about 15 minutes on my camera) move the iso down step by step. On my screen iso 5000 looks like silk.
Click to expand...

MUST...TRY....NOW :-)
 
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