"For me, the camera is a sketch book, an instrument of intuition and spontaneity."
― Henri Cartier-Bresson
Always read the owner's manual very carefully before you try to do anything related to your camera. Before you start to clean your camera's viewfinder, you need to first determine whether the dust has settled on the exterior or interior of it. Once you determine that, you should start cleaning this part of the camera.
If you have to clean the interior of your camera's viewfinder, then you have to be very careful while doing so, to avoid damaging the delicate glass and other smaller components inside the camera. Usually, most camera owners give their cameras to a professional for cleaning, but if it is only the viewfinder, then they prefer doing it at home. Given in this Buzzle article are some methods to clean the viewfinder of a camera. So, follow the instructions carefully.
★ Cotton swab
★ Lens cleaning liquid
★ Lens cloth
★ Rocket blower or air bulb
★ Lens brush
★ A small-sized camel-hair brush
External Dry Cleaning
★ Use a dust blower, and gently blow off all the dust from the viewfinder. This is very effective in getting rid off the dust and fine lint particles that have settled on your camera's eyepiece.
★ Take a lens cloth or a good microfiber cloth, and wipe the glass very gently and carefully. You can also use a lens brush or a small camel-hair brush for this process.
★ This step, which is called the dry cleaning step, removes the dust particles and lint that has settled on the surface of the viewfinder. But if there is moisture and sweat, due to which the dust is stuck on the viewfinder, then you need to go in for a wet cleaning.
External Wet Cleaning
★ Take some lens cleaning liquid on a lens cleaning cloth or a microfiber one, and gently wipe the glass in a circular motion.
★ If you are cleaning the hard-to-reach edges of the viewfinder, wrap the cloth around a cotton swab and gently clean the area.
★ If, by chance, you have used excess liquid, allow it to evaporate before keeping your camera away.
Internal Dry Cleaning
★ Detach the lens from the main body of your camera. Using the rocket blower, gently blow into the mirror. You can also gently brush the mirror using a small lens brush.
★ If you still feel that there is dust inside your camera, please take it to a professional, and get it cleaned thoroughly.
Internal Wet Cleaning
★ The procedure for internal and external wet cleaning is the same. But it is advised to avail professional help if you want to clean the mirror, sensor, or focus screen.
★ Never clean the viewfinder using a tissue paper, shirt tail, fingers, or cotton, to eliminate the possibility of getting scratches or other marks on the glass.
★ Do not use saliva or normal water to clean your camera's viewfinder.
★ Always keep your camera covered and protected from dust, when not in use.
★ If possible, you can ask the camera manufacturer to provide a viewfinder protector for your camera.
★ Never pour any liquid directly on the viewfinder.
★ If you choose to use canned air instead of a rocket blower, then make sure to test it out beforehand, to obviate any moisture from escaping.
To prevent major damage to the lens or viewfinder, clean them regularly. Use a small brush for the same, and store it in a clean camera bag. Always be gentle when you are cleaning your camera's lenses, viewfinder, or any part of the camera that has glass, as they are vulnerable to scratches and damage.