Hey everyone-
I'm looking to purchase a relatively inexpensive video switcher here soon and I'm looking for one that can chroma key different keys at once. I have a wall that is half painted blue and half painted green. What function would I need to chroma out both the blue and the green together in one compiled video?

You'll need a switcher that has a couple of keyers that you can put in series. The first will remove, say, the green, the second will remove the blue.

I was a lead engineer (there were only three of us) on the Grass Model 1000 and 1200 switchers in the early '90s. At that time chroma keyers were locked into the hardware design. They only key one one color at a time.

A 2ME switcher would be perfect. Key out one color on the first ME, then run that into the second.

A 1ME switcher could work if it has a downstream keyer with a chroma keyer.

A 1ME switcher might work if you output the first key on the preview bus, then send the preview back in to be processed on the 2nd keyer to the program bus. There might be a problem with re-entry though, due to timing issues. The end video will probably be shifted down a line or two, and (even worse) it might be shifted horizontally.

So, the 2ME or 1ME with downstream chroma keyer are good solutions. The 1ME switcher with re-entry would be a kludge.

All the best,

thank you so incredibly much. in the end im actually looking for a way to chroma out as many colors as possible. probably green, purple, blue, and red. i suppose possibly then i'd want to look for a 4 me switcher? anyway thank you so much for your help. any suggestions as well as to where to find a reasonably priced one? possibly used?

I would definitely look at the used market. I don't have any leads off hand. Lots of places that were doing online editing are now using non-linear editors. The lab where I work recently donated two Model 1200 switchers to Oregon State University. We do everything with computers these days. But OSU does live switching, so they have a good use for it.

Best of luck finding the right equipment...