Precomputed filtered vs Photon mapping + CI

[except]

I've found that for most of my scenes, from outdoor simple scenes to complex indoor scenes the precomputed filtered gives a good visual result and is much faster to render than photon mapping + irradience caching. What exactly is the difference, and why should I not be using precomputed filtered?

The prerender pass is not performed with precomputed, but does not seem to matter in most cases, unless very tricky GI solutions are in play. Other than that it's just a slow pass that

Is this about small details and contact shadows?

Attached image is precomputed filtered... 5 minute render time with FSAA, DOF and Motion blur. Pretty good I say
I cancelled the Photon mapping render after 8 minutes and it not being halfway done...

[erwin zwart]

Hi Tom,

precompute does not use any FG, so basically you don't have ANY contact shadow. It looks similar to LW's own GI FG interpolated with too high MES. In your beautiful scene the attention is drawn away from correct GI, so you can get away with it, but in more brightly lit rooms the difference is too much noticable. For exteriors it is a nice way to have some occlusion, but we cannot call it true GI.

added 2 pictures to clarify, see also the weird thing going on in the displaced sphere, that surprised me. I used this HDR lit scene because the less direct light the more clear the difference in lighting (this is always the case in GI)

[except]

makes sense.
thanks Erwin