How To Clean Your Projector Lens
When you hit the power button on your projector’s remote, in short order you have a vibrant image projected in front of you. It is easy to forget all of the steps that happened in between the image entering your projector and it being beamed onto your wall or screen.
A number of digital signals, zeros and ones, traveled through your HDMI cable. Light reflects off of specially designed mirrors and then goes through the interpolation process where it is translated from binary to pixels.
White light ricochets off of a number of specially designed mirrors, which in turn forces the light to travel through pixels that are the building blocks of the image.
This newly illuminated image is adjusted for color via LCD screens or a dichroic prism. However, this entire unique process can be negated if your projector lens is dirty, smudged, or dusty.
The projector’s lens is the end stage of the process. The lens is responsible for:
- Sharpening the image
- Properly magnifying the image
- Illuminating the image
- Adjusting image colors properly
When the lens is dirty, it needs to be cleaned. However, you cannot just go about cleaning the lens as you would a mirror or a glass window. In this guide we are going to discuss the proper way to clean a dirty lens before your next classroom presentation.
Overview
Before You Clean the Lens
- Turn the projector off
- Unplug the power cable
- Let the projector cool down
The Right Tools for the Right Job
When your sunglasses get dirty, you probably breathe on them, get them foggy, and then use your T-shirt to wipe them off. This process will not work with your projector lens. Just think about how much you paid for the projector. A large part of this price is because of the quality of the lens. The glass that is used to create the lens is exceptionally sensitive.
If you used a common cotton T-shirt to clean the lens, you would probably get the dirt off. However, the coarse fibers of the cloth would likely scratch the lens.
Our recommendation is for you to use a lens cloth, like those sold at a photography supply store. They are not very expensive, but they are soft enough to properly clean the lens.
Don't just use your tshirt or a kitchen cloth!
It is important that you keep the cloth dry, clean, and free of debris. You should also purchase a non-abrasive lens cleanser. Do not think that because it is liquid, the cleanser is non-abrasive.
Many liquid cleansers are abrasive, especially when used on glass. This is going to affect the quality you see projected onto the big screen.
Things to Avoid
- Avoid using alcohol
- Avoid spraying the cleaning solution directly onto the lens
- Avoid using left to right or up and down cleaning motions
- Avoid touching the lens with your fingers as the oils from your fingers will leave marks
The Proper Cleaning Technique
Once you have the right tools, you must master the proper technique. Do not overuse the cleaning solution.
The lens is small and only requires a small amount of solution. If you use too much solution, you’re going to find it difficult to clean the lens and keep it streak free.
Do not spray the solution directly onto the lens. Spray the solution onto your cloth first. Then, use the cloth to gently wipe the lens using a circular motion. The lens should look visibly clean.
When you have finished, put the lens cap over the lens, unless you are planning to use the projector immediately.
Dusty Versus Dirty
A dusty lens is different than a dirty one. For a dusty lens, we recommend using compressed air to blow the dust away. If you use a cloth to wipe the dust away, the loose dirt will lead to micro abrasions in the lens. This will minimize the overall quality of your picture.
In Conclusion
Hope this guide was helpful guys. Please make sure to regularly clean your projector especially if you're using a high end home theater projector or have spend a big chunk of money on a 4k projector.
Thanks!
My name is Steve Scott. Father of 2 and owner of Outdoor Movie HQ. I’ve been involved in the A/V industry for most of my life and built this blog to help people better understand projector technology. Please leave a comment if you have any questions.