Summary List:

Having a clean lens on your digital or cell phone camera is important for the quality of your photographs. Dirt, fingerprints, or a smudge on the lens can show up in the image or at least cause the image to be blurred. Professional photographers will tell you that you don't have to worry about dust as much as you may think you do. However, you should protect your lens with a lens cap and a filter and regularly clean your camera bag. On the other hand, you should avoid cleaning your lens as much as possible because cleaning it can scratch it.

What to Do to Clean the Lenses on Digital and Film Cameras

Check Your Lens for Dirt

To find out if your lens needs cleaning, follow these steps:

Set your camera to manual mode so that you can control the camera's focus.
Turn the focus ring on the lens to infinity.
If your camera has a viewfinder, look through it to check for dust.
Take two photographs, one of a dark-colored, plain surface and one of a light-colored, plain surface.
Set your camera so that you can view the photographs you just took and zoom in on them.
Closely examine each image for visible dust particles, hazy or blurry areas, smudges, lines, and streaks.
If you have interchangeable lenses, examine the rear element for smudges or dust.

Check the Interior of Your Lens for Large Dust Particles and Mold

The two photos you took should reveal any large dust particles, but there is another way to find out how much dust is inside your lens:

If you have an interchangeable lens, remove it from the camera.
Remove any filters from the lens and follow the cleaning steps below.
Large dust particles inside the first element of the lens should be visible with a quick inspection.
Perform a quick inspection by looking straight into the lens and then looking into it at an angle.
Remove the rear lens cap from the lens and open the aperture to its widest setting.
For older lenses, set the aperture ring to the lowest f stop setting (f/1.4 or f.2.8).
For newer lenses, you'll need to locate a small metal level, push up on it, and hold it in the upward position to keep the aperture open.
Take a bright LED flashlight and, with the lights off in a dimly lighted interior room, shine the flashlight into the lens through the first element toward the back element.
If you see mold on your lens or the lens contains so much dust that it's reducing the contrast in your pictures, call the manufacturer or an authorized camera cleaning service to find out how much cleaning will cost.
Disassembling and cleaning a lens may not be covered by the warranty, and a new lens may be less expensive.
If you see a large speck of dust that moves when you rotate the lens, something inside the lens may have broken off. Contact the manufacturer.
Do not try to disassemble and clean a lens yourself. You are unlikely to be able to reassemble it correctly, and you will have voided the warranty.

The first thing to do is to find out if your lens needs cleaning. If it does, then you'll need to gather your cleaning supplies. To clean your lens, you'll need:

A very bright LED flashlight
A soft camel hairbrush or a bulb air blower
A microfiber cloth or lens cleaning tissue or cloth
Lens cleaning fluid, eyeglass cleaner, or water (To clean vintage lenses, use alcohol-free cleaners. Alcohol-based cleaners can damage the coatings on older lenses.)

Gather Your Lens Cleaning Supplies

Choose an area with good light so that you can clearly see fingerprints, dust, and smudges.
Hold the lens pointing upward at a 45° angle and use puffs of air from a bulb blower to dislodge dust. Move from one side of the lens to the other.
To dislodge more stubborn dirt, use the camel hair brush and stroke from the middle of the lens to the edges. Then use the brush to dislodge dust from the edges of the lens. Point the lens toward the floor as you brush so that the dust falls off the lens.
Apply two drops of lens cleaning solution, eyeglass cleaner, or water to a lens cleaning tissue or a microfiber cloth.
Work from the center of the lens outward in a circular motion to remove grime, fingerprints, or oil.
If you're cleaning interchangeable lenses, repeat these steps to clean the rear element.
Replace the lens caps on the front and rear elements and use the bulb cleaner or brush to dislodge dust from the lens barrel.
Carefully dampen a microfiber cloth with a solution for cleaning lens barrels and camera bodies, or use water and wipe the outside of the lens.

Cleaning Your Lens

The most common causes of blurriness in a camera lens are smudges and dirt. If you've cleaned your lens and it's still blurry, you could have moisture in the lens. There are three methods to try to draw moisture out of the lens.

Let the lens dry in direct sunlight.
Place your lens in an airtight container or a Ziploc® bag, cover the lens with rice, place the container in a warm, dry space and leave it for at least 24 hours or up to a week to make sure all the moisture is gone.
Purchase silica gel from a hardware store, craft store, or supermarket and place your lens in the silica gel just as you would place it in rice. You may find that silica gel works even faster than rice.
If these suggestions don't work, take your lens to an authorized camera repair shop or lens cleaning service.

Why You Don't Have to Worry About Normal Size Dust Particles

You can minimize the amount of dust that gets into your camera and lens by avoiding changing the lens in a dusty environment, changing the lens quickly when you do need to change the lens, and changing the lens while keeping the camera and lens inside your camera bag or some other protected space.

However, as Nasim Mansurov writes for Photography Life in an article entitled "What to Do with Dust Inside Lens," even new camera lenses contain dust. Mansurov continues explaining how dust gets into lenses and which lenses are the most dust prone.

Even when you're doing macro photography, though, Normal size dust particles are so small that when the camera focuses on your subject, it's focused beyond the dust particles on and inside the lens. Those particles are too close to the lens to be inside what you can think of as the box created by the depth of field for the image. The depth of field is the distance between the objects in the foreground and the objects in the background of the image that are in acceptably sharp focus.

How to Clean a Camera Lens Without a Lens Cleaner

You don't need a lens cleaning kit to clean your lenses. In fact, you probably have items around your house that you can use to clean your lens, including:

A turkey baster or large eyedropper in place of a bulb air blower
An unused camel hair cosmetic or artist's brush in place of a lens cleaning brush
Microfiber cloths or cotton swags in place of lens cleaning cloths
Alcohol-based eyeglass cleaner or water in place of lens cleaning fluid

You can create your own lens cleaning fluid with a one-to-one blend of distilled water and 99 percent isopropyl alcohol. Place the mixture in a bottle similar to the ones used for eyeglass cleaner and shake to blend the water and alcohol.

What Not to Use to Clean Your Lens

There are several things you should not use to clean your camera lens. These include:

Window glass cleaner can damage the coating on the lens.
Your breath can introduce moisture that can condense inside the lens, creating conditions for the growth of mold.
Facial tissue may scratch the lens or contain lotions that can leave smudges and streaks on the lens.
T-shirts can be made of rough fabrics. If you must use a t-shirt, make sure that it's made of 100-percent cotton and that it has not been washed with a fabric softener. Fabric softeners can also leave smudges and streaks on your lens.
Reused lens cleaning tissues; these should be discarded after a single use.
Microfiber cloths that have been washed with fabric softener.
Toothpaste can be too abrasive, especially toothpaste with whiteners.

How to Clean the Camera Lens on a Phone

You can clean the camera lens on your with many of the same items you would use for your digital camera lens. Here's what to use and how to use it:

Start with a bulb air blower or a two-sided cleaning pen as you would if you were cleaning your digital camera. Cleaning pens have a brush on one end and a soft, padded side on the other.
Dry lens cleaning cloths or microfiber cloths can be folded into a triangle-shaped point and used to gently rub the lens to remove smudges, dust, and dirt. Both are portable and take up little space. They can fit in a pocket. However, without a cleaning solution, you could scratch your camera lens.
A drop or two of lens cleaning fluid, ammonia-free eyeglass cleaner, 70-percent isopropyl alcohol, distilled water, or Purosol placed on a lens cleaning cloth or microfiber cloth will remove more stubborn smudges with less of the rubbing that could scratch your lens. These are available in small, purse-sized bottles.
You can also dip a Q-tip or other cotton swab in distilled water or a cleaning solution. Cotton swabs are the perfect size and shape for hard-to-reach areas on your phone's camera lens. Just be careful of scratching your lens with the rod supporting the swabs. The swabs can also leave lint on your phone or camera lens.
Disposable pre-moistened lens cleaning wipes combine lens cleaning cloths and lens cleaning fluid in a small, individually wrapped package. An overly-moist wipe could leave streaks on your lens, though.
In the same way that a lens cap protects the lens of a digital camera, a lens protector protects the lens on your cell phone. Lens protectors are available for most cell phone brands.

Summary List:

Use a brush or a bulb air blower to dislodge dust and dirt from your lens to prevent scratches.
Follow up by putting a drop or two of lens cleaner on a lens cleaning tissue or a microfiber cloth.
Start from the center of the lens and work out to the edge in a circular motion.

Conclusion:

Keeping your cell phone and digital camera lens clean ensures that you'll be ready to capture sharp, clear images of whatever happens around you. To avoid scratches, don't clean your lenses more than you need to, but do check them regularly to see if they need cleaning.

For more tips on caring for your camera, join the community at Daisie and expand your photography knowledge with expert-led workshops.