Good morning! Has anyone else had trouble getting a good matte using the HSL Qualifier (I'm going to assume the answer is no )? Every time I try to get a good qualification, it's always super grainy. I expect this coming for DSLR footage, but I still even have trouble with F3 footage. Even with softening the qualification and putting a slight blur on it, I feel like I can never get as good of a key as I can in a compositing application (with a simple key, nothing fancy). Am I crazy!?
Depending on the shot, a lot of times it helps to disable one ore more of the qualification channels. For example if you are isolating a specific range of a single color, try disabling the luma qualifier. other situations you may try turning off saturation or hue. Sometimes that can really clean up a key. Also don't be afraid to combine a window with your key so the key doesn't have to work so hard - the key doesn't need to be perfect for the whole screen if you can window out the rough spots.
Totaly. I've done this with some success. The biggest times i have trouble is when I'm qualifying skin tones. So yeah, maybe just a hue qualifier with a window will do, if there isn't another 'skin toned' color near by.
I don't use the color picker anymore. I start with the luma channel and then the hue and saturation last. Luma is always the cleanest channel and I find that skin is always in the top half of the luma so it's easy-ish to key that way
Qualifiers usually require a lot of fine tuning. Resolve offers one of the best qualifiers out there, but it is not an automatic process. The problem with skins is that usually there are shadows involved, so a highlight may fall out of the range of a shadow. You can try to expand the selection using the little eyedropper with a plus sign next to it. If you have a control panel, this fine tuning process becomes considerably faster. What I usually do, in cases where I am having some trouble, is to add one extra node and independently key the area I'm having difficulties with in the first node. In fact, you may have to combine several nodes under certain though situations.
Thanks Dan, I'll give that a shot. I've started to do this as well, as you would do in a VFX shot, it's still a matter of getting it clean that's tricky.
ProTip: Use a separate node, sourced the same as the one you are trying to qualify. Do noise reduction on it. Then use the NRd clip to pull you qualification, feed that matte into the regular node you're trying to use for skins.
You could also do an intermediate render of a NR'd clip for the purposes of getting the qualification, if realtime NR is going to choke you out, or you happen to be using Lite. (right?)
To check your qualification use the B/W matte mode, this will show you the noise. It's a mode that sorts the men from the boys/girls
Hi Marc, You're receiving quite a bit of good advice from some great talent. I echo Warren's response, and especially Juan's pro tip. Throwing my two cents in …I worked on 3 different projects this week. All 3 required HSL Qualification, and all 3 ranged from easy to challenging. A commercial that I graded was shot on Canon 5D H264, and was probably the most challenging of the 3 to work on. The black and white matte that Warren suggested helped a lot. So did the new node, as suggested by Juan. I needed to pull multiple keys, so using a Key Mixer node to build the effect helped. Masks (power windows) most definitely certainly helped. But it took some doing, which I put down to the quality of the video and the type of shot I had to work with. But I got the job done. Did a simple HSL Q on a 2k .dpx project, which was done quick as a wink and Bob's your uncle. This afternoon I did an HSL Q on some BMCC footage shot in 12-bit RAW for a reality show. By far this was the simplest of the 3 to do. Easy peasy. From my point of view, there are so many factors that go into getting a good HSL Qualification. Plenty of good advice in the replies above. Good luck. Best, J
