Every DSLR owner worries at some point or another about dust on lenses. While dust on the body of the lens is fairly easy to clean, dust on the elements is more tricky. You can clean the barrel and rubber rings on the lens using a moist toothbrush or a soft cloth. You have to be careful not to let drops of water run into any of the cracks below the zoom and focus rings and enter the lens. Ditto with the switches on the lens.
Cleaning Lens Elements
A disclaimer before we get into more detail – unless you know what you are doing, it is always better to leave a lens alone or seek expert help. We know – we have been in situations where we left a lens worse off than it was before we began cleaning it!
Prevention is definitely the better option. Which is why almost all of the lenses that go out from Primes & Zooms carry a UV filter. The filter protects the front element from dust, grime, spray and minor impact. We have had cases where customers have come back with the UV filter broken but the lens intact. A filter is easier and cheaper to clean and replace than the front element.
Despite using a UV filter you will occasionally find dust on the front element. The best way to clean this dust is to use a rocket blower. This will take care of the loose particles but sometimes there may be more stubborn residue on the element. In such cases, use a Lenspen – these come with a carbon fibre tip that can lift dust particles off the lens. This also works for rear elements although you have to be more careful with cleaning rear elements, ensuring you do not damage the electrical contacts.
Sometimes, water droplets that have dried on the element will leave stubborn stains that refuse to go away even with a lenspen. Gently moisten the stain by breathing on the lens element and clean it with a lenspen. Anything that does not go away at this stage probably needs harsher methods and should either be ignored or left to the service center.
Dust Inside the Lens
Lenses are not built to be airtight. Air will and does move in and out of a lens every time lens elements are moved such as when you are zooming or focusing. Every time air circulates, it will carry dust inside with it and this dust settles on the inner elements. Most of the time, this dust is harmless and will not affect your image unless you are shooting with a wide angle lens and have stopped down enough that the focal plane extends to the front of the lens. If you see spots on your image stopped down, it is more likely to be sensor dust. If you see dust in the optical viewfinder, it is more likely to be on your mirror and focussing glass than on the lens. Dust inside a lens is normal and rarely visible in the viewfinder or in the image. Do not go overboard trying to clean the dust off inner elements – even if you manage to do it, it will find its way back in there eventually! If you are tempted to open up a lens to clean the dust off, do consider that you may be introducing more dust into the lens by the act of opening it. If you absolutely MUST have it cleaned, take it to the service center.
Talk To Us
If you have an abnormal dust issue with your camera or lens, get in touch with our technical team at support-at-primesandzooms-dot-com. They will be happy to guide you on the best way to solve the problem!
Founder, Primes & Zooms