Speedgrade: protune to 709.cube limit range of files

Question

Forgive me I don't know a whole lot about color correction or speed grade as a whole so it will be difficult for me to communicate what I am having an issue with. I recently recorded multiple clips with a GoPro in 4K. I put all the clips on the same time one in premiere Pro and exported them to speed grade.
for some of the clips when I apply a look up table such as pro tune to 709.cube it works fine.
however on others when I apply the same look up table it limits the amount I am able to adjust the clip. For example on the RGB parade it only goes to maximum of 70 on one clip and 50 on another.
then on some of the other clips it allows me to do a full range of adjustments and it goes all the way to 100. All these clips recorded the same way and with the same settings so I don't know what the difference would be. I've done nothing but import them and then send them to speedgrade.
I cannot figure this out if anybody can please help me I would greatly appreciate it I don't even know the correct terms to search for Google.

Answer 1

In order to get there and NOW I've started doing a couple things that aren't 'typical' procedure especially when in run & gun mode. Such as put an Expodisc in front of the lens and film a couple seconds while having it pointed sort-of towards the light falling on the area to be shot at least a few times during an event. Yes, I will completely balance to that to start with and if I've got the time may do so later during the event also. But I will just hold it in front of the lens for a second or two (again, quick pointing semi-towards lightsources) every so often, and with that set for middle value on the camera I can then get a pretty decent neutral grade very fast in post.
On loading the items onto my timeline, I'll put things together as they fit ... but before sending over to Sg to grade, with the PrPro bin set for name sort (I don't tend to rename footage) I'll maybe insert a couple of the short gray sections in their appropriate spots in the sequence, use them in Sg to get a quick neutral grade and copy that to the following clips, then color/style those clips. Back in PrPro I'll delete the gray sections. Takes a few seconds to add them, a few seconds to delete them, and saves a LOT of seconds getting to neutral. (Note ... testing your camera by doing a couple seconds at "normal" exposure, then a couple seconds each 2 or three stops under/over isn't a bad idea. If the gray of your shadows always goes a hint of green, but your upper tones go a bit cyan from the middle tones, then you know something to correct or build a Look for that camera.)
The two biggest things I learned to start with grading: 1) TRUST YOUR SCOPES NOT YOUR EYES! and 2) don't confuse neutralization and final coloring!
Waveform gives you a great look at your tonality ... use it to set your bottom & top values. Parade is great for neutralization especially combined with Vectorscope ... watch the three colors in the Parade, and look to the center of the vectorscope ... if there's any significant area that is totally gray/white/black it should align with the center of that scope ... color saturation is higher to the edges, less towards the middle ... and NO color at dead center. If you've got some decent total neutrals no matter light or dark, but nothing centered on the vectorscope, well .. you adjust until that is centered. If you've got a lot of skin, there's a line that runs from the center up to the upper left oft called the "skin" line ... which it isn't but is for all practical purposes. Sometimes I'll put a hard mask on a clip so I'm only seeing someone's face and check that the color stays pretty close to that line.
Getting a good neutral gets you started ... but rarely is it pretty. But without neutral, it's DAMN hard to get to pretty. Go for neutral, then start trusting your eyes to go for pretty.
Neil