http://img158.exs.cx/my.php?loc=img158&image=penyaf6dc.jpg
what would be the prefered way to get the reflection of that bitmap-image in the ball? with an envmap? angmap? ray-mirror? hdri?
too much tree´s in the wood… 
thanx for a short help!
this one seems to have been made with HDRI or AngMap. It seems to me that it’s more a Blender internal render than a Yafray, so I’d say AngMap.
Both seems to have been made with Ray Reflections, anyway.
So I think that to decide which method you should use to obtain such results, you should first decide which renderer to use: blender internal or yafray? It’s more a matter of implementation, then… Personally, I’d use Ray+Ray mir+AngMap.
To get that quality, he used HDRI in Yafray. How to use it (read BgDM’s post):
https://blenderartists.org/forum/viewtopic.php?t=34115
Ofcourse the ball has to have ray-mirror on too.
An angmap with an envmap would work too, but the quality would be less. As you can see in this image (the Blender internal version with an angmap):
For example everything in the reflection has the same brightness when not using a HDRI, while in the real world light emitting objects are sometimes the only thing visible in reflections. AFAIK Yafray doesn’t support envmaps.
Oh, and it isn’t “just a bitmap”. It’s a HDRI! 
One thing I did which worked fairly well was create a dome as a sky, and textured cloud image to it. then I increased the emit light slider in the shaders tab in case it wasn’t bright enough in the reflection.
you might take a couple lamps and light the dome if you go that route.
some people use the world icon and create an image, but I’ve never found that function.
be careful your lights dont’ reflect strangely in the ball, it might look like you are shining lights around the room. a photo I did looked real, but it had 2 suns in the reflection and looked wierd.
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