I've searched the forums with no luck....I'm having an issue with foliage models that are visible while in a scope, but disappear when the player brings down the scope. I've seen this in several maps. There isn't any problems with prefabs, only foliage models.

Are there any models which don't disappear?

that usely has to do with your vid card i use to have that prob to i got a 8800gtoc card now it looks fine no matter what

My vid card is 8800gtx....and this happens to others with similar cards....could be a portalling issue.

Its not the card...its part of the properties of the model.
Models have an LOD (level of detail) - a distance from the player over which the model isn't drawn.

As far as the game is concerned, when you look down the scope you've basically 'moved' the players head forward a few 100 yards, so those models that were previously out of viewing range now jump into range and get drawn...........drop the scope, the player 'moves back' and the models are out of range again.

I assume they all have the same LOD and any model I choose would be affected.

i think you can hex edit the models to use only the highest LOD, or create or own model

its basically like an ingame version of cubic clipping
if you select cubic clipping on your mission editor you only see whats near you
same dif
its a graphics settings in your options

If you are looking in to way a way too change then it will probably be classed as 'draw distance'. Not sure you can change it though.