Dust Inside Lens: When Does It Matter ?

Dust inside lens is a very common problem for photographers, especially in the summer months. It is important to clean your lenses regularly and to use a lens cleaning kit, but there are other things you can do to avoid getting dust in your lenses.

In this article, we will explore the different ways you can prevent dust from entering your lens and will tell you how to take care of your lenses without any tools or kits.

1) How To Inspect Lens For Dust

If your lens is dirty, how can you tell if it’s working properly? Rather than asking how much dust is in your lens, I’d like to rephrase the question. Due to the fact that even brand-new lenses frequently contain foreign particles in the space between the lens elements themselves. If there are any large dust particles behind the first lens element, a quick visual inspection of the lens front will reveal them. Just be sure to thoroughly clean the front of the vehicle and remove any protective filters before starting the restoration process. If you look straight at the lens for a moment, and then inspect it from an angle, you may notice some dust on the front glass element. This is the best way to see dust if you insist on seeing it, and believe me, you will. Start by locating a powerful LED flashlight. These days, you can find them just about anywhere, including the grocery store. The next step is to increase the lens’s aperture (the lens obviously needs to be dismounted from the camera, rear lens cap should be removed). Aperture rings are still available on older lenses. To use one of these rings, simply set it to its lowest value (which is also the largest aperture) such as f/1.4 or f/2.8 and you’re good to go. Modern lenses, such as Nikon “G” type AF-S lenses, require you to open the lens aperture by pushing up a small metal lever as shown below. Keep pushing the lens aperture lever with your index finger to keep it wide open.

Turn on the flashlight and point it towards the back of the lens with the front lens cap off once the lens aperture is fully opened. Make sure you’re in a dimly lit room with the lights off when you do this. Look at the lens’s front element from an angle to check for dust buildup. If you’ve never seen any dust before, you’re about to see it for the very first time. You can now see dust between all of the lens elements because a bright light shines through the lens and makes it visible. Now, a word of caution: as I’ve previously mentioned, even if you’ve just purchased your lens, you shouldn’t be alarmed to see dust on it. Dust, small bubbles, and other flaws in the glass are examples of the types of particles that could be present. Why? It’s true what they say about no lens being perfect. Fortunately, every one of my lenses, including the brand new Nikon 35mm f/1.4G prime I just received from B&H Photo, is covered in dust. Here’s what my Nikon 24-70mm f/2.8G lens looked like after a few years of heavy use:

And here is how the Nikon 50mm f/1.4G looks:

That sure does look scary, don’t you think? However, it makes no difference to me because both lenses deliver excellent results and will do so for many more years to come.

2) How And Why Lenses Get Dust

You may be perplexed as to how and why dust accumulates inside lenses. First, some background information on lenses. If you focus or zoom in and out repeatedly, your lens will “breathe” as a result. And no, I’m not referring to the phenomenon known as “lens breathing,” which occurs when the focus is shifted – I’m referring to the act of inhaling and exhaling. Lenses must be able to exhale because of the constant movement of the lens elements within them during focus adjustments and/or zooming. When pressure builds inside a tightly sealed plastic container, remember what happens? If you try to shrink the container, the internal pressure will only allow you to shrink it so far before pushing you back. Air pressure is a simple concept in physics. Now, apply the same theory to lenses. Think about what might happen if lenses were completely sealed on all edges. You can only zoom in so far before the lens puts too much pressure on you and makes you return to your original position. This is especially true for lenses that extend in size. Lens focus has a similar effect. As a result, camera lens manufacturers had no choice but to design lenses that inhale and exhale air. In terms of controlling air flow, some lenses are superior to others. Lenses that cost hundreds of dollars are more likely to be dust-sealed (which only keeps a small amount of dust from entering the lens), but consumer zoom lenses are the worst because they can pull in outside air and blow it right into the camera chamber. Let’s see which lenses do the worst job of dealing with dust.

3) Lenses Prone To Dust

Some lenses, as I mentioned above, are more susceptible to dust than others. In order from “worst to best,” here are the lens types most susceptible to dust buildup:

3.1 – Consumer Zoom Lenses With Extending Barrels

Take the 18-55mm f/3.5-5.6G VR DX or the 18-55mm f/3.5-5.6 IS lenses from Nikon or Canon, for example. Rubber gaskets that wrap around the camera mount are absent from most low-cost plastic consumer lenses. When working in a dusty environment, they’ll draw in dust from the outside, which gets sucked into the lens and then the camera body.

3.2 – Professional Zoom Lenses With Extending Barrels

For instance, the Nikon 24-120mm f/4 VR and the Canon 24-105mm f/4L IS are both excellent examples. For the same price as expensive professional-level zooms, Canon and Nikon lenses with Red and Gold rings offer similar weather protection. However, because the barrel length varies so much, the latter are more susceptible to dust buildup. Dust can enter the camera chamber through the lens mount if the lens has rubber gaskets to seal it.

3.3 – Expensive/top-of-the-line Professional Zoom Lenses With Extending Barrels

Nikon 24-70mm f/2.8G and Canon 24-70mm f/2.8L are two good examples. Professional zoom lenses at the very top of the market will have better weather sealing on the entire lens. Rubber gaskets are always included, and other parts of the lens, such as the zoom ring, focus ring, switches, and so on, have rubber seals as well.

3.4 – Professional Zoom Lenses With Fixed Barrels

Nikon’s 70-200mm f/2.8G VR II and Canon’s 70-200mm f/2.8L IS are good examples of this. Lenses with constant diameter barrels are better at withstanding moisture and dust. There are fewer places for dust to collect because the camera is stationary. Dust can enter the lens through any number of openings, and rubber gaskets and seals are used to prevent this from happening.

3.5 – Prime Lenses With Extending Front Element

To give you an idea, there are lenses like the Nikon 50mm f/1.4D and the Canon 50mm f/1.4 USM. Because there are fewer moving parts inside prime lenses than zoom lenses, they are less likely to collect dust. Even though prime lenses with a moving front element are preferable to zoom lenses because they change in length as you focus, dust can still enter the lens from the front. When the rubber gasket on the camera mount is missing (as it often is on older models), dust can get into the chamber and onto the lens.

3.6 – Prime Lenses With Fixed Barrels

As an illustration, consider the Nikon 35mm f/1.8G and Canon 24mm f/1.4L II. Lenses with non-extending barrels, such as primes, provide the best dust resistance. A moving rear lens element may be present in some prime lenses with rear focus features (such as those from Nikkor, such as the 24mm f/1.4G and 35mm f/1.4G), while others have a fixed glass element. As a rule, the latter performs better. There are many rubber gaskets around the lens mount on modern prime models of today, and high-end models have additional weather sealing in other parts of the lens as well.

The prime lens is better protected against dust than the zoom lens, as you can see. In some cases, primes are worse than zooms at dealing with dust and moisture, but this is rare.

4) What To Do With Lens Dust

What should you do if you find lens dust on your camera lens? Nothing, is the answer. Just keep shooting and don’t give a damn about what anyone else thinks. The same as dust on your camera’s sensor, lens dust is an unavoidable fact of life. No matter how meticulously you clean and care for your equipment, you will still end up with dust in your lenses and cameras. Cleaning and maintenance (which I will cover in a future video tutorial) will help to reduce the amount of dust that gets into your gear, but it is impossible to prevent it entirely. If you have dust on your camera gear, don’t worry about it. It will get there eventually. Experiment with looking out a dirty window in your house and see if you can detect anything unusual outside. Is it possible to see the dust or dirt on your window when your eyes are focused on the outside? No, except if the dirt particles are colossal in size. It’s the same with dust particles in the lens; they’re not a big deal if they’re small. Now that you’ve taken a deep breath, it’s time to relax and forget about the dust.

The only time you should contact your lens manufacturer is if you notice a large dust speck that moves when you rotate the lens, which is larger than a few millimeters in size. Particles can break off inside lenses after they’ve been dropped or damaged, but this is rare.

5) How To Remove Lens Dust

Never, ever attempt to clean the inside of your lenses by yourself. In addition to voiding your warranty, disassembling your lens virtually guarantees that you will be unable to put it back together again in the same way it was originally. Call the lens manufacturer and ask whether they can clean the interior of the lens and how much it will cost if large amounts of dust are heavily affecting your images and you have a very low level of contrast. The disassembly and cleaning of the lens’s interior are NOT covered by the normal lens warranty, so you’ll have to fork over a hefty sum. You’ll save money by purchasing a new lens rather than trying to fix an old one. To be clear, you should never try to perform this task on your own, and you should never allow someone who isn’t a professional to do so on your behalf.

6) Minimizing Dust And Fungus

When you shoot in a relatively clean environment, store your gear in a cool, dry place, and take good care of it, you can eliminate the growth of fungus and reduce the amount of dust that ends up on and in your equipment by regularly cleaning and maintaining it.

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