I have had to use a disc shaped light for this lamp, but the reflections of the light source are too bright (TV screen):
I tried to use a sphere, but the light leaked and gave a bright ceiling in the corner even when the source is within the shade. I tried to use spots, but the beam angle only goes to 90º. Anyone any other ideas?... I'd rather not do any post-production.
If I understand you right, you are talking about lights, not emissive materials yet? Did you tried emissive materials? Last I was surprised how good emissive materials works now. It was looking like they are working like lights, only better.
The inside of the lamp and the bulb are emissive: cranking them up to max leaks onto the ceiling, gives a bloom and a much softer light; the disc shape gives the effect I am looking for, but I went with the spotlight option in the end.
So, stay to hope the max spot angle will be increased for further releases. Spot are my most used light sources too.
An other idea - you could use a group of spot lights instead a single spot and so you could get a wider angle. I tested 8 lights but it doesn't look so good, but 16 lights was fine. It wouldn't be so much a problem to use a high light count for your little scene. If I remember me right per default you can set 256 lights and see them all at the same time.
You can use IES lights if you want full control over your lights. This way you can also tune the angle falloff.
Are IES lights for Rhino available?
+1
same here
milos.komlenic and octavio , +2 for the topic! 
+1
You can use IES lights if you want full control over your lights. This way you can also tune the angle falloff.
Totally agree. I'm using IES for most of my scene that generally use downlight as main source light. But, not to set it on high value, it can make your scene ambience becomes darker than before.
Sounds like an automatic brightness dim the complete scene.
