Oh, yeah, I was that newbie that ruined the shot once. I was lucky, and given a second chance. I went on to have a great career. But I still ruined the shot. It'll haunt me forever. And since then, I've seen a handfull of newbies walk into trouble, in other, similar ways. Some made it through, some didn't.
We were installing a SPFX wall on a location. It was a cinderblock wall. We used a wood core and applied foam brick skins to it. In the center, an explosion was designed to blast through the wall. In this area, we used full size foam bricks; there was an opening in the wood frame to accomodate it.
As we were laying in the bricks, we were adding talcum powder inside, bettween the cracks, inside the wall so that when the explosion was triggered, there would be the effect of concrete dust coming out from the explosion. "Just put a bit in each crack", the head painter handed me the talc. I had never done this before.
I poured "a bit" in each crack as my partner installed the bricks. We added the mortar to the outer edges, and sealed up the wall. We painted it, it looked fantastic.
But the following day shit hit the fan. The shot was ruined. There was way too much talc in the cracks, and the explosion just looked like a big white cloud puff.
Why did this happen? Because I didn't ask, "What's a bit?"