13 
I can’t even count how many times I used my breath to fog up a camera lens to wipe it down clean. It’s the photog equivalent of blowing into those old NES cartridges. I swear it works! Turns out, we might be ruining our camera lenses because our breath has harmful acids that can damage them.
PetaPixel pointed out a Nikon support thread that specifically says not to use your breath:
Do not breathe on the lens to fog it for cleaning. There are harmful acids in breath that can damage lens coatings.
Uh oh. Then what the hell are we non-professional photogs supposed to do? Nikon says Lens Cleaning Solutions are the best (no abrasives, no solvents) but if you don’t have that, use “the blower bulb, then brush, and wipe the lens in a circular spiral from the center outward.” The more you know, right. [Nikon via PetaPixel]
By the time it has any impact you wont care about just buying another one or a whole other camera.
That’s a silly thing to say when you consider some lens cost thousands of pounds ( you’d upgrade the camera body & keep the lens- the money is in the lenses after all ). It’s only true if you have a shitty little point & shoot that’ll be outdated or dead in 2 or 3 years.
I object to you saying that lens cleaning solutions have no solvents in them. For starters, they’re called solutions, implying they’re a liquid with stuff dissolved in, thus the liquid is a solvent.
No solvents that act on the coating materials would be more accurate.
“wipe the lens in a circular spiral from the center outward”
This goes against everything I believe in.
Didn’t blowing into NES cartridges cause more problems in the long run?
I would always keep a UV filter on the front anyway to protect from any scratches etc. When it’s badly damaged just chuck it and put a new one on.
don’t good ones cost a lot anyway?