Dave wrote:

Hi,

What is the best thing to use to clean a smudge (like a finger print) off a
lens? I know to use a protector filter but I have lens to clean that didn't
have one. I heard that some liquid type cleaners are not good for lens
coating. Is there a popular cleaning kit or cloth to use?

There is a special lens cleaning fluid which I think is the same as
sensor cleaning fluid. My eclipse sensor fluid says it contains
methanol, a volatile solvent. I've used that with some lens cleaning
'papers' on a bad fingerprint once but I generally do the microfiber
kitchen cloth & a breath to fog. Don't use microfiber with solvents, it
might melt the synthetic fabric. If using a solvent, put a drop on the
lens paper or pad, don't dribble it on the lens.