New flowers, burnt tips?

[Pickle Rick]

Ok I usually grow in dwc but this is my first soil grow. My bag seed outdoor grow is starting to flower and I've noticed little brown specks so I investigated with my jewelers loop. Anyone have any input on why it looks like it's burning tips?

 

[leather lungs]

Soil residue?

 

[Pickle Rick]

Soil residue?

I don't think so. My buddy thinks it's light burn but it only gets direct sunlight for a couple hrs tops.