Ok, my Harraps confirms that usually 2me plan means either middle ground or background in theatre terms. I guess you're going to have to be a bit creative with this large stage. I would suggest foreground, part-middle ground, middle ground, part-background, background, or some such variant.

I give a link related to compostion of shots in film-making.

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Note added at 4 hrs (2008-07-19 08:32:31 GMT)
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or perhaps better semi-middle ground, etc.

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Note added at 4 hrs (2008-07-19 08:38:00 GMT)
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Upstage, downstage is also used.

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Note added at 4 hrs (2008-07-19 08:47:18 GMT)
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Here is an example of the stage being divided into 'different spaces', http://query.nytimes.com/gst/fullpage.html?res=950DE4D7133FF...

It is clear exaclty what is meant by the term, but as Vaughn has made clear, the actual way it is expressed is somewhat different in EN, I feel. I've not personally encountered this type of term, but I'm sure it dates back historically to when the scenery used to be slidd on and off stage on 'tracks', thus defining quite fixed positions between the scenery where entrances and exits could be made.

I would attempt to convert to more meaningful EN expressions, once you have found out if your list of 5 'planes' is exhaustive. if so, it might go soemthing like this:

1er plan DS [= downstage]
2e plan middle DS
3e plan mid-stage
4e plan middle US [= upstage]
5e plan US

I emphasize that these are my own 'invented' terms, I cannot back them up with solid refs.

There might be some argument for using 'centre' instead of 'middle', but personally, I feel that is confusing, sinc eit could be taken as meaning the centre of the stage laterally.

In our theatre, when we wanted to refer to a precise position in the US/DS sense, we would often refer to the number of the (lighting) 'bar' immediately above it (or to the space between 2 bars) — so we might have "cut cloth #3 woodland on Bar 5" or "entrance between bars #7 and #10". But I don't know how general this terminology is.


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Note added at 5 hrs (2008-07-19 10:15:03 GMT)
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Given that the different points at which performers enter/exit will be clearly defined elsewhere, all you have to do is express which of the pre-defined points it is.

A bit complicated, I know, but:

There are traditionally 6 different parts to the performing space:
upstage (farthest from audience), center stage and downstage; stage left and right (from actor's point of view).
The wings are equivalent to the offstage area (the part hidden from the audience), generally along the left and right sides. There is usually masking with curtains (called legs or tabs) and/or flats (generally canvas on a wooden frame used either as part of scenery or painted black).

I have not managed to turn up any strict equivalents for "plan" (indeed not very common in French theater either as far as I can see), certainly not dividing the stage into 5 horizontal bands. So my suggestion is to refer to the wing masking/ legs/tabs/flats in order to give a more precise place from which to enter.

http://tomhares.wordpress.com/glossary/
http://www.terryotooletheatre.org.uk/pages/TOTTechnicalInfor...
http://en.wikipedia.org/wiki/Parts_of_a_theatre

the large stage is separated into blocks, and then the actors are told in which block are they to perform. if a smaller stage, then up-stage and the others work for blocking as well.