+1 Bel-Air Camera in Westwood
+1 the "Grand Circle"
+1 Cali_PH
I've been to a lot of the places mentioned on this thread, and while they're all awesome, Yosemite really is a step above in terms of natural beauty. That said, given the time of year, the number of days you have, and your photographic interest, I'd skip Yosemite on this trip and would do the "Grand Circle" instead. Cali_PH is right about the water levels. Plus, from a photographic stand point, Yosemite is totally overphotographed. If you want to make some compelling and unique photos, you REALLY have to work for them (i.e., hiking to unique perspectives.)
Here's a google map from Lancaster, through the Grand Circle, back to LAX.
http://goo.gl/maps/Mk4vbThis would take you to Flagstaff for the South Rim of the Grand Canyon, the Petrified Forest, Canyon de Chelly, Moab for Arches and Canyonlands, Natural Bridges, Capitol Reef, Grand Staircase-Escalante, Bryce, and Zion. It's about 1750 miles, but you should add at least another 250 for driving into and around the parks. Definitely doable during your time frame, as I basically did the same route (minus the Grand Canyon and Zion) in a little over a week.
You could shave a couple hundreds miles off by doing the North Rim instead. Missing out on Moab, Arches, and Canyonlands, though, would be a bummer.
http://goo.gl/maps/plh12Either way, you'll see a stunning amount of the American West, and MUCH more than a trip to Yosemite. Furthermore, you'll see places (like Capitol Reef and Grand Staircase) that few Americans ever see.
BTW, if you do find yourself in Torrey, do yourself a favor and eat at Cafe Diablo. That restaurant is amazing, and if it was in LA or NYC, it'd be a critically acclaimed restaurant charging a king's ransom for haute Southwestern cuisine. Call ahead, though, as they do close for the winter.