"But there´s one point I´m straightly opposite to yours and that´s the lens.
I would recommend just a 28-35mm lens on 35mm/fullframe (d)SLRs or for digital DX nothing less then 20mm. Here´s why:
If I shoot the way you used to (and most of the ones outside doin´) in the advertising my room seems to be very large and nice, that´s why you all are doing that.
Problem is, that reality can not mess with it. You face that if you showing your client the real estate and his first impression is:
>>Uhh! I thought it was bigger.<<
Bad position to start a sales talk.
If a single wall in a room can not get in one shot you can stitch. It requires some accuracy and time, but that´s why you get paid instead the Realtor doing it himself."
Dom's point is that there are downsides to using a lens that is too wide. The perspective looks strange and exaggerated and can make an average living room look like a bowling alley. For my taste the place where wide angle starts to become too wide is around 24mm. Below 24mm perspective starts to look strange because it is vastly different than the human eye. The image above is shot at 16mm. The white coffee table in the foreground has strange distorted look and depth of the room is very exaggerated. This is the effect that Dom is talking about.
I know I have many examples on this blog that were shot between 16 and 24mm. When I first got my 16-35mm zoom in 2003 I shot with it at 16mm most of the time. I admit I was infatuated with ultra wide shots. But I got negative feedback. One seller call the photos "cartoon like" one potential buyer called about a listing and ranted on about how I had purposely distorted the images to make them look bigger. Since then I've managed to get hold of myself.
Now days here is my rule of thumb: I try not go below 24mm unless there are unusual circumstances like a small powder room or important room that I need to shoot but just can't do it without going lower. But to me 28mm is just not wide enough. There is a lot (8 degrees) of HFOV difference between 28mm and 24mm. Sorry Dom we'll have to agree to disagree.
I'd like to hear what others experiences are on how wide is too wide.
June 19 update:
By perspective distortion I do not mean converging verticals. I can tell by peoples comments that many think I'm talking about converging verticals. The term exaggerated perspective is probably a better term. The exaggerated perspective I'm talking about here is making the room look much bigger than it is.