Combine Delta Keyer and Luma Keyer

Hey I'm trying to combine a Luma Keyer mask and a Delta Keyer mask for this shot. My apologies if this is a simple solution I'm use to after effect for masking and keying.

The simplest -- though not the best, most flexible -- way to do it is to feed the output of your LumaKeyer into the input (yellow) of your DeltaKeyer. Then in the DeltaKeyer's Mask tab choose Solid Source Alpha: Subtract.

I'm not sure the actual best way for your purposes, but the MatteControl node could take the outputs of the two keyers and you could set it to Combine Alpha, Minimum, and perhaps turn on Post Multiply Image.

In either case, a Clean Plate (the pink input of DeltaKeyer) is a totally different thing than an a matte. The key thought here is that you want to combine two alphas, or maybe take one alpha and refine it with another. Your LumaKey isn't a garbage matte, a solid matte, a clean plate, etc, so it won't feed into any of those inputs on the DeltaKeyer.

It's possible that you could use one keyer as a solid matte or garbage matte for another, but the solid and garbage mattes are treated specially when combined and don't enter the equation as "equals" of other alphas that are contributing to the overall alpha in the same way. In your case it appears that you want to take the two alphas and combine them (equally), though.