Is this feature suggestion totally crazy?

[Fergus Cahill]

Often as Cinematographers we have to change exposure during a shot. Less so true in commercials, but very true in doco or drama.
I watched a talk recently with Yves Bélanger CSC, where he said that he would change ISO during a take rather than the T' Stop, compromising his DOF.

So here is my crazy suggestion. What if we could dial ISO in infinite numbers? E.g between 800-100 we could go to 924,925,926 etc in a smooth progression.

Is this even possible? Would anyone ever use it?

Certainly the strangest idea I have ever posted. but just wanted to throw it out there!

 

[Björn Benckert]

Why would you do it? its only meta data and does not mean anything else than that you try to be a creative colourist while shooting. So why not leave post to post.

 

[Christoffer Glans]

Just change it in post, there's nothing "burned" into the file if you shoot R3D.

 

[Ryan Sauve]

This might be a dumb question but how do you ramp ISO up and down in post? I thought you could only set it to one level for a given clip and if you change it, it changes the whole clip to the new level.

 

[Christoffer Glans]

This might be a dumb question but how do you ramp ISO up and down in post? I thought you could only set it to one level for a given clip and if you change it, it changes the whole clip to the new level.

Well, good question, that you cannot do, even though it would be nice if software like Resolve could keyframe the Raw settings. But in general, it's the same as gain or offset, so just setting the ISO to a mid setting and using those settings to animate between different exposures should produce the same result.

 

[Marc Wielage]

This might be a dumb question but how do you ramp ISO up and down in post? I thought you could only set it to one level for a given clip and if you change it, it changes the whole clip to the new level.

We change exposure all the time in post, but we do it with gain or curves or any number of ways. And we often do it dynamically or selectively as a ramp, depending on what happens with the camera. For example, if a move starts on one side of the room and dollies to a different side of the room, we'll build in a slight exposure change -- say, 1/4 stop -- to compensate for the difference in lighting. And sometimes we'll selectively flag or illuminate different things in the frame with tracking windows. I do this every single day with many, many shots.

I wouldn't worry about changing exposure or T-stop during the shoot, but I would worry about getting a reasonable image within a comfortable range for the given chip. A "balanced" histogram helps.

 

[Fergus Cahill]

I guess the reason to do it in camera is that not everyone gets to go to their grade?

 

[Björn Benckert]

I guess the reason to do it in camera is that not everyone gets to go to their grade?

Is there no way to assign FLUT increase/decrease to a hotkey / slider on the side handle or such?

Still, is that what you want to fiddle with while shooting.

 

[Marc Wielage]

I guess the reason to do it in camera is that not everyone gets to go to their grade?

You can always send notes and stills to the colorist, or know them enough to trust them to not screw it up. There's a lot in this business that boils down to trust and competence. Without that, it goes south very fast.

I have worked quite a bit by remote with DPs and just sent them stills on key scenes so they can get a rough idea if what they're eventually going to see is close to what they wanted (and expected). The DP isn't always available to be in the room, but I always try to at least have a conversation with them (on the phone or via email) to get an idea of what issues might be in the material and what I need to watch out for. The key is for the colorist to protect the DPs work and not stomp all over it.

 

[Terry VerHaar]

Fergus - as others have said, changing ISO is only changing metadata and is, with a RED camera, very different than changing exposure. The "usual" way of thinking about ISO is that raising it introduces electronic gain into the system so the camera "sees" more light, at the expense of introducing more noise.

In the RED system, changing ISO is effectively changing the curve that's applied to the exposure, shifting middle grey up or down, but doesn't change the dynamic range of the scene that is being captured even one bit. Meanwhile, quite obviously, changing exposure on the camera does change what the camera is actually able to see and capture - at least until you blow out the highlights or get lost in noise on the bottom end.

So, while changing ISO during the shot might change your ability to monitor the signal, it changes nothing in the captured image that can't be otherwise changed (or reverted) in post.

One last thought, even if you can't key frame ISO in most post tools, which, if possible would allow a nice smooth shift, you could, in a desperate situation, cut the clip and change the ISO metadata for the different segments.