Scarlet-W Low Light

[bart cortright]

hey there,

a lot of clients / directors have been asking me about low light with the scarlet-w so I figured I'd make a little test video. If it's helpful for anyone else feel free to use! I used a shot that was exposed for 3200 ISO and showed it at 1600, 3200, 6400 and used neat video's de-noiser v4 to show how far that could go.

Also, sorry for the strange nature of the aspect ratio - this is from a feature film I shot over the summer that was shot at 6:5.

 

[Matthew Quinn]

Where is the link sir?

 

[bart cortright]

oh odd, it isn't embedded above?

here is the link ! - https://vimeo.com/180530050

 

[Bob Gundu]

btw, you wont see embedded videos on iOS.

 

[Matthew Quinn]

ahh got it now @@

 

[Marc Hutchings]

Neat video does a great job, now I'm going to ask.a stupid question - it doesn't matter which iso you use when you actually shoot does it? Fixed at 800 and just meta data right? So if I shoot at iso 400 and in post change it to 3200 it would be the same as shooting at 3200 in the first place? Haven't got my head around that yet!

 

[Bob Gundu]

Neat video does a great job, now I'm going to ask.a stupid question - it doesn't matter which iso you use when you actually shoot does it? Fixed at 800 and just meta data right? So if I shoot at iso 400 and in post change it to 3200 it would be the same as shooting at 3200 in the first place? Haven't got my head around that yet!

Yes you're correct.

 

[bart cortright]

Neat video does a great job, now I'm going to ask.a stupid question - it doesn't matter which iso you use when you actually shoot does it? Fixed at 800 and just meta data right? So if I shoot at iso 400 and in post change it to 3200 it would be the same as shooting at 3200 in the first place? Haven't got my head around that yet!

ha, yeah it still blows my mind that it's possible. It's definitely one of my favorite reasons why to shoot RED.

 

[AndreeMarkefors]

…it doesn't matter which iso you use when you actually shoot does it? Fixed at 800 and just meta data right? So if I shoot at iso 400 and in post change it to 3200 it would be the same as shooting at 3200 in the first place? Haven't got my head around that yet!

Provided of course, that you don't adjust aperture or shutter to compensate for how your monitor looks when changing the ISO.

If 400 was the "correct" ISO at f2.8 and you set your camera to ISO3200, and then when the image on the monitor gets brighter you stop down 3 stops with aperture, shutter of filters… well, that is the road to ruin right there.

I'm only mentioning it since I'm sure there is someone shooting a RED somewhere, this very moment, doing that very thing.

The most common way this happens is probably someone setting up for a shot in a darkish environment. Since it's dark they go "Well, I'm going to need at least ISO1600 here, so let's set that". THEN they adjust aperture for exposure. Let's say they land on f2.8.

If you wanted the texture of ISO1600—great, mission accomplished. If not, you could have rated the scene at ISO400 and then shot it at f1.4. That's a different texture.

 

[Daniel Stilling]

I'm sure there is someone shooting a RED somewhere, this very moment, doing that very thing.

And every time someone does that, a bunny dies, or an angel loses its wings or... you get the idea.
In low light (night, etc) never, ever ever stop down. Adjust the ISO first. Let that light goodness wash over the sensor all the way until it clips...

 

[Michael Greenwood]

Looks fantastic Bart!
Also stumbled upon your reel.
It's stunning! Great grading - all around!

 

[Marc Hutchings]

The only killer with neat video is the processing time what kind of fps do you guys get with it at 4k in resolve?

 

[Chris McKechnie]

And every time someone does that, a bunny dies, or an angel loses its wings or... you get the idea.
In low light (night, etc) never, ever ever stop down. Adjust the ISO first. Let that light goodness wash over the sensor all the way until it clips...

I'm pretty sure you know this as a well experienced/seasoned DP yourself, but for the others who are new to RED -

ISO has no relevance on what the RAW sensor is seeing even though it's reflected in the RBG histogram. As you adjust ISO, the histogram reflects the various changes but again, no impact/fluctuations on what the RAW sensor is actually seeing.

So I adjust ISO only as a last possible resort to "increase" brightness, not exposure. You first want to open up as much as you can and adjust frame rate/shutter speed to get what is as close to proper exposure, then adjust ISO for the proper "brightness."

RAW R3D's are a very powerful thing...understanding/using them correctly is vital to maintaining an amazing image that not only looks decent on set, but gives your colorist room to make it really come to life.

 

[AndreeMarkefors]

ISO has no relevance on what the RAW sensor is seeing even though it's reflected in the RBG histogram. As you adjust ISO, the histogram reflects the various changes but again, no impact/fluctuations on what the RAW sensor is actually seeing.

So I adjust ISO only as a last possible resort to "increase" brightness, not exposure. You first want to open up as much as you can and adjust frame rate/shutter speed to get what is as close to proper exposure, then adjust ISO for the proper "brightness."

What I and Daniel are saying is that you can use your ISO as a canvas on which to paint. By specifying a certain ISO you can control you texture and light distribution relative to 18%. It can be a deliberate choice.

What you're saying is correct, but it's assuming you always want as little noise (or texture) as possible. Of course it's a valid choice to always maximise signal to noise, but it's not the only choice.

Anyway.... as long as people realize ISOs don't "let more light in"... we can save the butterflies, bunnies and angels.

 

[Michael Tiemann]

Provided of course, that you don't adjust aperture or shutter to compensate for how your monitor looks when changing the ISO.

^ This. There are literally thousands on threads on RU that come down to somebody fooling themselves by setting a high ISO in camera (perhaps because they wanted to shoot slowmo), seeing something encouraging on the monitor, and then closing down the aperture to dial in the right amount of darkness, only to find in post that they had completely starved the sensor and absolutely ruined their capture. The Monitor is for framing and focus. Histogram, stoplights, and GIO Scope (or other false-color tools) are for exposure. Unbelievable how many will spend so much on a camera without understanding these basics.

 

[Sean Connery Smith]

Getting out my notebook.. Wait .. my Notepad.exe

 

[Neil Abeynayake]

^ This. There are literally thousands on threads on RU that come down to somebody fooling themselves by setting a high ISO in camera (perhaps because they wanted to shoot slowmo), seeing something encouraging on the monitor, and then closing down the aperture to dial in the right amount of darkness, only to find in post that they had completely started the sensor and absolutely ruined their capture. The Monitor is for framing and focus. Histogram, stoplights, and GIO Scope (or other false-color tools) are for exposure. Unbelievable how many will spend so much on a camera without understanding these basics.

To add to what Michael stated; since you've already invested 12 ~ 20k on your camera therefore, it is not a bad idea to take the REDucation class.