The best place to photograph the back of the Hollywood sign is on the asphalt road directly behind the sign and just below the peak. From the peak, you will look down on this asphalt road about 40 feet below you. At this location on the road there is a six foot high chain link fence that keeps people away from the sign. You can either use your cell phone to shoot through the links in the fence for an unobstructed shot of the back of the sign, or if you have the reach you can lift your camera or phone over the top of the six foot high fence for a completely unobstructed view of the back of the sign.
When I stood in front of that fence ready to photograph the sign, two things became clear to me:
1. The Hollywood sign is very wide.
2. The Hollywood sign is very close.
The sign would not fit inside the frame of my camera, but I could not back up and stand further away from the sign because the fence would encroach into the frame. Since I was so close to the sign I would need a very wide angle lens, such as a 14mm on a full frame camera, in order to take a single image with the entire sign in one frame . If you have this lens then great, but for me this meant I needed to shoot the photo as a multi image panorama. Good thing I love taking panos! Here is how I took this shot.
I selected a location where I was directly behind the letter Y on the sign, and was directly in front of a fence post to decrease the possibility of camera shake because the fence was going to support the camera. I extended the legs on my tripod to full length, but I did not spread the tripod legs; instead I kept the three legs together like a monopod. I had brought two stretchy bungee cords with hooks on the ends just for this location, and I used one bungee cord to mount the tripod to the fence at the very top, and the second one at the very bottom. My tripod was rock solid while mounted to the fence with my camera about one foot higher than the top of the fence. The difficulty was that my arms had to reach up and make adjustments to the camera that was high over my head. It was difficult to see the camera settings, so I had to take the camera off the tripod a few times to adjust focus, ISO, aperture and shutter speed. I used a wired shutter trigger to take each image at that height and so as not to cause camera shake. I love that thing and I use it for all low light photography. The trick is to wait at least four seconds after last touching the camera before taking the next photo. If you don't have a remote trigger, you can set your camera's self timer for two or five seconds to reduce camera shake.