Ok, so I have a giant cavern that ive made, looks great, only problem I am having is the lighting. It is blinking off and on in certain places/camera views. I have looked around and seen other people having this problem. Some have mentioned to do the room portals, however most seem to be using them in housing mods or dungeons with smaller rooms/hallways. Will those work well with such a large rendered space? (think Ustengrav and the Horn of Jurgen Windcaller quest) Also as a side note, I currently have ZERO shadow lights in the space. (did not want to add them untill i get the lighting issue fixed)

Screenshots below for an idea of the cave size.

http://imgur.com/M9WP7,dBvya

It's because you have more than 4 lights near the player. Either delete some or http://skyrim.nexusmods.com/downloads/file.php?id=10361

There's also the http://www.creationkit.com/Bethesda_Tutorial_Lights_and_FX which I found helpful. And then there's the http://www.creationkit.com/Bethesda_Tutorial_Optimization which has a few very effective details and showcases a handy lighting testing tool provided as part of the Creation Kit.
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One little trick is to try to avoid having any given object lit by more than two lights - three at the most. However, this can be impractical for large objects, in which case try to avoid as much overlap as possible between the areas of surface on the object struck by different lights. I've found that even little things like this can make a great improvement. I had the same problem in my mod and, although I haven't completely optimized my mod, these little steps were all I required to eliminate the problem (and a few others which I thought unrelated).
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