Originally Posted by boojum
OK, Decca made some masterful recordings in their heyday. It seems they used the Decca Tree for a lot of them. Is this technique still in use? If not, why not if it is so good? I am not trying to be snarky and I would really like to know.
Yes, it still is in use often. It's the most common main setup in score music (because of L-C-R, of course!). With lots of additional spots.
As it never had just one fixed spacing (like ORTF has), but every engineer tried out different approaches, one might call quite a few LCR setups "Decca-ish". Doesn't necessarily need to be on one stand.
Other setups like ORTF or XY, and even spaced pairs, are way easier to calculate - see Williams' Stereophonic Zoom or the hauptmikrofon.de web app. When setting up a Tree-style main system, you need to listen even more carefully. Actually, the ORTF setup was developed by french radio (which ORTF stands for!) in order to have a quick-setup, good-enough sounding standard way to record. Very bureaucratic