So, you bought you beautiful new home for the views of the City, the Bay, the hills beyond and now, a few years down the road, your neighbor has let his scraggly pines grow right into your view. What can you do? If you live in a town with a view ordinance, you may be able to do a lot. Most view ordinances allow you to retain the view you had when you moved in. Have you documented it? Photos of the view, which you must have taken when you fell in love with the property, can help immensely when proving you have a case, whether in court, mediation or in front of a "tree committee."
First, know the rules. Does your town have an ordinance? in Marin, Belvedere, Tiburon, Sausalito and Corte Madera do, these are the towns with the best views (water, bridges, city skyline mostly) and the often the highest home costs. However, even if you don't live in one of those communities, your homeowners' association may have rules for trees and views. Check your local ordinances and your CCRs (if you have them), to be sure.
Then talk to your neighbor about the issue. Will he allow you to trim for your view? If not, you may need a good land use lawyer, specializing in tree law. It is a specialty, one that depends a lot of good expert help from a consulting arborist. Make sure you use a good one if you have the situation evaluated before hiring that attorney. In any event, a good consulting arborist (not just a certified arborist), can help you decide your course of action, even if he's not allowed on the neighbor's property to assess the trees themselves. Looking at the view, the growth patters over the years (this is where the photos help), and other factors give your arborist a good method of assessing the situation to be able to help you talking to the neighbor, working with the tree committee, mediating the situation or in court if all else fails.