How to Clean Your Projector's Lens
There are a lot of checkpoints that an image has to go through in order to be projected onto your screen. The digital signals, all of those 1's and 0's, have to travel down an HDMI cable A beam of white light has to bounce off a series of specially treated mirrors. It has to go through the process of interpretation, be translated from binary signals to pixels. A beam of white light has to bounce off a series of specially-treated mirrors and pass through the pixels which make up the image. The newly-illuminated image has to be treated for color, either through LCD screens or through a dichroic prism. But all of this is for naught if the lens in your projector is smudged, dusty, or otherwise dirty.
The lens is the final checkpoint. The lens is where the final image, colored and illuminated correctly, is magnified, sharpened, and bounced onto the screen for your entertainment or enlightenment. Hence why it's important that your lens stay clean. In this article we'll go over some of the proper ways to polish your lenses so they're ready for your next outdoor cinema event.
The Tools for Lens Cleaning
The lens for your projector is not a pair of cheap sunglasses that you can clean off with the bottom of your t-shirt. On the contrary - the kind of glass used for you lens is very sensitive, to even the most minor of abrasions. The coarse cotton fibers on common every day clothes would perhaps get dust or unwanted smudges off the lens, but they would leave the lens' glass with a legion of tiny scratches. With that in mind, what you want to do is visit a photography supply store and get a lens cloth there. It won't be that expensive and it will soft enough to clean your lens. Make sure to keep that cloth dry and lint free. You'll also need a non-abrasive lens cleaner solution. Be sure that it is non-abrasive - you'd be surprised to find that some liquids are actually abrasive to glass!
Cleaning the Lens
Remember that when it comes to cleaning solution, less is more. You only need a small amount of solution. Anything too excessive is just going to make it harder to get the lens clean and streak-free. Also, be sure to never spray the solution directly onto the lens itself. Instead, spray the solution onto your lens cloth. Wipe the lens gently, in a circular motion until it appears clean. Be sure to put the lens cap back on when you're finished, unless you're going to use your projector right then.
When the Lens is Dusty
Different problems call for different solutions, right? If your lens is more dusty than dirty, you don't need to break out the cloth and solution. Instead, grab a can of compressed air and blow the dust away from the lens. Wiping the lens with a cloth when there's dust or loose dirt on it will only cause micro-abrasions in the lens, which will affect your overall picture quality. Remember to hold the compressed air at least seven inches away from the lens when you're spraying.
As a projectionist, keeping your lenses clean is going to be absolutely vital - particularly if you're going to be putting on a lot of outdoor cinema events. You should make cleaning your lenses a part of your regular set-up and strike routines. If you do so, it will a long time before you'll need to buy a replacement.