Colour grading - avoiding noise / maintaining native ISO

Shebbe gives great help. I'll add though that no camera is noise-free. There is always signal noise, and the camera processing is setup to minimize this as much as possible without doing worse damage to the image.

So depending on what changes one does, one can start showing visible noise with any camera. It's how you do your changes that may create less noise and artifacting than using the tools a different way. Taking practice and some experience to learn. But to me, that is a fun trip ... 😉

A color "surface" ... control panel, can make a huge difference in both the speed of what you do, but more importantly, the range of things you can do.

For example, manually normalizing log video to linear display space. Doing this in the Basic tab is actually pretty slick, working mainly two controls with and against each other. Therefore, if you can do them simultaneously, you can both work faster and see the interim states more clearly.

A Tangent Ripple is what, $350USD or so? Do much, that alone will pay for itself. I've both a full Elements panel in suite, and a Ripple for my laptop or on the road. Either way, I've remapped controls so the Basic tab controls are all ... simultaneously! ... on the ball & rings. One tool mapped for the ball's horizontal motion, another for the vertical motion.

My middle ball is Contrast. Both "contrast" and "saturation" are actually contrast controls, right? So my middle ball is mapped so that tonal contrast is set to vertical movement, saturation contrast is set to horizontal movement. Exposure is mapped to the ring for that ball.

So I'm working Exposure, Contrast, and Sat ... simultaneously. As one example of what a surface control can do. And yea, manually normalizing log footage is a breeze.

Shebbe is also right about the Exposure control dual types of movement. The Exposure control expands image contrast when going up, sorta like grabbing the White end point of the RGB curves tool, though with a roll-off on the white point. And as Shebbe notes, it's different going down ... a simple end-point pull down, no shape changes.

The Contrast control expands outward from, or in towards, the 50 IRE mid point of the Waveform or Parade scopes

Combine the two ... Exposure both increases overall 'contrast' while moving the center point up. Contrast moves out from the current center point. So use Exposure to set where you want contrast to expand from as the center, and Contrast to set the overall push out from that center.

You'll probably want a bit of Sat or Vibrance change to taste also, maybe do a slight trim with Shadows, Highlights, and Black control.

That's one way of working the process. And once you've got it to a setting you like, and works well on several images from that camera, SAVE that as a preset. Then when you get that camera in the future, in log, select all the clips in the bin. Drag the preset from the Effects panel to them, slam bang DONE. All normalized.

Perhaps a better question is what is your intent? And are you using the right methods and tools to achieve that?