Fungus in Lens – How to Fix it With Step-by-Step Instructions

Great camera lenses are super expensive – there’s no real way around that fact. For this reason, finding invaders like fungus within your equipment is a terrible experience. Most standard warranties don’t cover lens fungus damage and it can significantly affect the performance of your gear.

It goes without saying that the longer you can make your lens last, the better. On this page, we’ll explore the fungus-in-lens problem. We’ll explain how to fix a lens that’s already been damaged but, more importantly perhaps, we’ll discuss how to prevent the problem from happening in the first place.

Read on to protect your gear.


What is Lens Fungus?

Dust and similar particulates are everywhere. No matter how careful you are, it’s inevitable that at least a small amount will make it onto and into your equipment over the years. Fungus can start to grow if this dust contains any fungus spores.

The annoying thing about spores is that they can stay dormant for a very long time. They can sit undetected for months and years, waiting for favorable conditions to arrive. Once things are just right, they start to grow and ruin your expensive camera lenses.

How to Avoid Fungus on Lens – Can You Prevent Lens Fungus?

Absolutely. There’s no method that’s 100% sure to prevent all damage, but fungus can be avoided fairly easily if you keep a few basic principles in mind. In short, fungus relies on the following elements:

  • Heat
  • Moisture
  • Darkness

It stands to reason, then, that your main line of defense against lens fungus will be to keep these three conditions at bay. If your lens ever becomes damp for any reason, be sure to dry it out fully and as quickly as possible.

Consider silica gel packs to help with storing your equipment. Just remember that their effectiveness as a solution to water damage is questionable; they’re designed to absorb moisture from the air. For this reason, they’re best used as a preventative measure rather than something that can fix water damage.

Keeping things nice and cool won’t hurt either. Also be sure to wipe down your equipment regularly and use your lens caps as often as possible when you’re not taking photos. If your lens stays cool, dry, and is regularly exposed to UV light, the chances of lens fungus reduces dramatically.

How to Clean Fungus From Lens Without Opening it

So, is it possible to clean fungus from a camera lens without actually opening it up? There are a few things that can definitely help. Just keep in mind that the only way to completely remove fungus from a lens is to open it. If you’re not comfortable doing this, consider sending it in for repair.

Repair costs can be a tough pill to swallow, but when weighed against the cost of a new lens, they’re usually worth it in our opinion. That said, let’s get into a few ways to clean lens fungus without opening it up.

Fungus Cleaning Option One – UV Exposure

Be careful with this one – too much direct sunlight can damage camera lenses. However, UV exposure is a fungus spore’s worst nightmare. Shining some UV light on your lens can eliminate fungus invasions pretty effectively.

You might like to follow these steps:

  1. Remove the front and rear caps from your lens
  2. Take out any UV filters if you’ve been using them
  3. Expose the lens to your UV light source for at least several hours

With this method, you stand a decent chance of killing the fungus, but it won’t remove it from your lens. Hardened residue may still affect your equipment’s performance. Using a UV lamp will help you to avoid exposing your lens to further dust and contaminants outdoors.

Never look directly at a UV light source.

Lens Fungus Option Two – Copper Coin Moisture Removal

Check out this great YouTube tutorial here:

The driving principle behind this method is that copper has antifungal properties. You’ll be using some towels and copper coins to draw moisture from your lens and kill off any fungus that’s inside.

You’ll need the following:

  • Some copper coins – roughly 50-cents worth per towel
  • Some hand towels
  • A dryer

Follow these steps:

  1. Put a good handful of copper pennies into a few small towels. Wrap them up tightly and secure with a rubber band.
  2. Dry out the towels thoroughly in your dryer. Just a quick 10-minute cycle will do.
  3. Place your lens and the towels in a sealed ziploc bag. This will eliminate moisture and hopefully kill your fungus.

As with method one, this option can be pretty effective at killing fungus but it won’t remove hardened residue from your glass.

Lens Repair Specialists

We wanted to mention that it really is only worth dismantling a lens if you’re absolutely sure you know what you’re doing. You can end up doing more damage if you’re not careful which can quickly turn a small repair job into a much larger one.

The following online repair sites might be able to help for less money than you might think:

Many of the big lens manufacturers like Sony and Canon also offer their own in-house solutions. Check them out first before taking your lens apart

How to Clean Fungus from Lens – Our Guide

The first thing to mention is that every lens is a little different. It’s impossible for us to provide detailed instructions that will be exactly the same for every lens. That said, the same basic principles apply to most lenses, especially the older manual varieties.

The items you will need are listed below.

Cleaning Solution

We recommend using a solution of equal parts household ammonia and hydrogen peroxide. These can be picked up from your local pharmacy or online. You’ll be using this solution to clean the glass and metal elements of your lens and eliminate all those irritating fungus spores for good.

It doesn’t hurt to have a small dish around to help with soaking your different components. This could be a bowl you no longer need or anything else you can find.

Dismantling Equipment

You’ll most likely want a set of JIS screwdrivers (if your lens is Japanese-made) and a lens spanner to take your equipment apart. These tools are perfect for working with lenses and are much less likely to cause damage. Also make sure you have some very clean microfiber lens cloths to hand as well as some decent tweezers.

The Right Environment

You will need plenty of bright light and ventilation in equal measure. Your cleaning solution isn’t something you want to breathe in directly. Finicky projects like lens repair demand plenty of light so you can see things clearly while you work. Consider a good lamp if you haven’t already.

A pair of protective gloves and glasses won’t go amiss either. Pick some up if you haven’t already.

Lens Air Blaster

A “poofer” or blaster like will make it much easier to remove solution and debris from your equipment without rubbing it too much.

The Dismantling Method

If you value your lens, keep the following in mind:

  • Any step you take will have to be reversed when putting your lens back together. Keep a record of each step so that you know which way everything fits in place.
  • Be very careful with the smaller glass elements – they can be super fragile
  • Find specific dismantling instructions for your lens if at all possible
  • Work slowly, patiently, and with certainty

In a Nutshell

In short, you’ll be doing the following:

  1. Carefully dismantling your lens
  2. Soaking the ‘infected’ elements and carefully removing debris
  3. Cleaning the rest of the unit if required
  4. Drying off each element
  5. Putting everything back together

Remove the Lens Mount

Use your JIS screwdrivers to remove the screws holding your lens mount in place. The number of screws you’ll be dealing with will vary but it should be at least 4 or 5. Put them in a safe place and remember where you removed them from.

Remove the Aperture Ring (Watch Out!)

When doing this step, look for a series of notches somewhere on the aperture ring. This shows you where you’ll need to be extra cautious. Behind these notches is a tiny ball and a tightly wound spring that will shoot it across the room if you’re not careful. Be ready to catch this ball when you take the ring out.

Take Out the Rear Element

Use your lens spanner for this and very carefully remove the rear element from your lens. Be sure to set your spanner to the appropriate width when doing this. Refer to your tool’s user manual if you’re unsure. Place all your elements that you’ve removed so far onto one of your very clean microfibre cloths.

Remove Each Glass Element and Clean

You’ll now be able to carefully remove each glass element from your lens. Pay close attention to the correct orientation for when you’ll be putting it back together. Soak each ‘infected’ element in your cleaning solution and then gently rub it with some cotton wool.

This shouldn’t take more than a couple of minutes per element, but some heavier invasions can take a fair bit longer. Rinse each element under clean water once the fungus has gone. Then use your air blaster to blow away the remaining water droplets before finally drying with a microfiber cloth.


Carefully reassemble your lens following the photos or notes you took while working. Well done – you did it!

Lens Fungus Cleaning Conclusion

We hope you found this page helpful. Our advice is to only attempt dismantling a lens if you’re very sure you know what you’re doing. There’s no shame in hiring a professional in situations like this.

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