It appears to me that there is the usual crowd of aspiring filmmakers but not a ton of filmmaking at the national festival level. If you want to make a living at it, that is. We have a mainland friend who's in the business, and she thinks Hawaii has a reasonably good reputation in some areas, although not-so-much in mainstream films other than as a location.
Louis Vuitton sponsors an annual International Film Festival on Oahu each October, and Maui has a nice festival in June. We've seen several documentaries and one dramatic short ("The Ride," about time-shifting with Duke Kahanamoku) as part of prior years' Maui festivals. There are occasional local contests with open entries -- a few years ago there was an open call for films to promote the preservation of Ahihi-Kina'u Natural Area Preserve.
There are plenty of surf and watersports films made locally, and quite a few cultural documentaries. I particularly recall seeing documentaries on the restoration of Kahoolawe, one on Hokule`a voyaging, and one watersport feature called "Pipeline Masters" that was way more interesting than I thought it would be.
I think whether you would find it a good environment for filmmaking largely depends upon what you're looking for and why you would choose Hawaii in the first place. A recent thread is entitled "Why are there so few movies filmed in Hawaii about average everyday Hawaiians?" (Link:
Why are there so few movies filmed in Hawaii about average everyday Hawaiians?)
Honolulu has some very talented design, production, and special effects groups, but the islands' remoteness and the lack of a noted, established film community like one might in a select cities stateside (not like LA or NY, but like Austin, Baltimore, or Miami -- or other odd moviemaking hubs) might be challenging. Or crippling. Or inspirational, depending upon how you look at it and how you (plan to) work.
Good luck.