please explain: skylight portal

[Freelance3D]

can someone please give a detailed explanation what are the pro´s and con´s of the skylight portal feature and what are the other option (store with irradiance map) are good for.

should the GI solution not work correct without the skylight portal used for windows?

is it only to bring more light into a room?
if the answer is yes then why not use a normal vray light?

i don´t get the principle yet.

thanks for your time.

[percydaman]

I haven't found alot of use for the skylight portal. Its supposed to focus the Skylight into small spaces, but found the quality and speed lacking compared to just a regular vraylight. Thats what I would use.

[RErender]

The main use is in conjunction with Photon Mapping, they allow you to focus skylight into photons/subdivisions .

[TrtSmrt]

Can anyone give more detailed description and pros&cons
THX!