So here’s how to fix that.
Two big things that you’re going to need are a microfiber cloth and a Q-tip cotton swab. These will be used. Then what you’ll also need are one of two items. The first one is Isopropyl alcohol. It’s very highly recommended when it comes to cleaning any sort of electronics–lenses included. Personally though, I’m a bit wary about what it may do to coatings–though I can’t prove this scientifically.
The other alternative is Purosol, which has enzymes and is plant based. It’s been used on LCD screens, televisions, plasma screens, etc. I’ve been using it for a while now and actually like it.
When cleaning the glass of the lenses, I truly only recommend cleaning the front element and perhaps the back element if it’s needed.
When using Purosol, simply spray it on the elements and wipe it off in a circular motion using a soft microfiber cloth. Add a bit of pressure to ensure that streaking doesn’t happen.
When using Isopropyl Alcohol, you can use a cotton swab and spread the alcohol around rubbing it to get all around the surface. When you’re done, wipe it down with the microfiber cloth. This method is really good if you’ve come from the outdoors and something like a bug is stuck on your lens.
That’s the first part of cleaning your camera lenses.
So why would you go about cleaning the contacts of your lenses? You’d be amazed what it can do. If suddenly you start finding the autofocus of your camera to be sluggish, then part of it could have to do with the contacts.
Cleaning the contacts removes dirt, grime, dust, and anything else that can hinder the communication between the camera and the lens.
With isopropyl alcohol, just use the cotton swab dipped in the alcohol and rub it into the contacts. That should take away any sort of dirt blocking the full communication.
With Purosol, just spray it on and wipe it down.
This gets a bit tougher when it comes to cleaning a camera contact. Your best bet is to honestly just use Isopropyl alcohol on the cotton swab and work with the contacts. This will loosen and get rid of any sort of dirt there.
After this stage, you’ve successfully cleaned your camera lenses. Now get to shooting!