lens - What is the best way to clean lenses and filters?

After removing dust with an air pomp and a brush, what are you using to remove stains from the lens and filters?

So far I'm using the liquid from a Giotto's CL 1002 cleaning kit for the lens, but I'm not sure what should I use for the filters, and if there is some better alternative.

Also, what kind of brushes are recommended?

Answer

Do not clean your lens (too much). Cleaning marks are by far the most common source of damage to lenses. Shooting under normal conditions, it takes a large amount of dust and grime to have any effect. The same approach applies to filters; good filters use the same type of glass and coatings as your lens (though perhaps not the same absolute quality).

This is the approach I try to take with my various old lenses (some dating from the 50s):

How to clean less

1. Use a hood. This will protect the lens from accidental finger-marks, light rain and other hazards when you're actually using it.


2. Put the cap on when you're not using it.



3. Put it in a case/bag/drawer when it's not on the camera (remember to use a desiccant if you live in a humid part of the world and will be storing it for a while).


4. Store it lying down. Dust drifts downwards, so don't point the front/back element upwards.

Alternately or additionally to the above, a protective filter. I wouldn't personally recommend it, but many people (particularly camera store sales staff) do, so it may be an option for you.

How to clean best

Materials: I use a camel-hair brush from the local art store. I just picked the softest one. A good camera store will stock similar, or something like a LensPen. For cleaning solution, I use ROR, which is a mixture of dilute ammonia, isopropyl alcohol, and a mild surfactant. Microfibre cloths are pretty easy to get these days, but the oldest cotton t-shirt you own is also a decent choice, particularly if you haven't washed your microfibre cloth recently.

1. Brush/blow away big dust.


2. Consider stopping there, it's probably 90% of the problem.


3. Spray a small amount of ROR on the cloth. It should not be wet, too much will streak.



4. Wipe gently, try to use a new section of the cloth for each stroke.


5. Do not rub or scrub, just repeated gentle wipes.

This can take 20 minutes for a lens that's sat in the closet of a heavy smoker for 15 years, but for a lens in daily use is perhaps a 5-minute job, tops. For a bit of context, most of my lenses have been cleaned like this once, when I bought them. Thereafter, just a brushing now and then, and another cleaning only if I manage to stick my thumb on them (or similar).

Credit where credit is due: this is a fairly common approach, but I first saw it in Karen Nakamura's section on Cleaning and Maintaining Classic Cameras which is a great source of information.