pvdhaar
Peter
dberger said:Oh brother. . . not only is it a myth, but this spit-enzyme-harming-lens-coating myth does not even apply. Amylase, which digests starch, is the only enzyme of note in human saliva. There are other salivary enzymes, but the whole issue is moot because to clean a lens, you are supossed to breath moist air on it, not spit all over it. Moisture in the warm, moist air from the lungs condenses on the lens surface in nice teeny-tiny droplets, which you then wipe off with some form of micro-cloth. No saliva should hit the glass. Voila.
cheers,
David
Hmmm.. theoretically, this is correct, but it's not backed by personal experience. In the contrary. A while back, when I got the first dust bunny on the sensor of my DSLR, I thought 'Hey, I'll gently blow it of. I'll even take care not to spit on it, just gently blow'. What happened was so counter intuitive, that I should have kept the test pictures after that and written a scientific article to be published in Nature..
After the moisture of my breath evaporated, there were huge numbers of very tiny spitlets (is that what they're called?) on the sensor. Basically it looked like I had airbrushed the sensor, and I had even made conscious effort to avoid that. It took much effort to get it all off the sensor again..
So, even though you take care not to spit on a lens, it's quite probable that it still ends up there, complete with enzymes, and whatever else there can be there like bacteria.
But all that will not even be as harmful as the acids, oils and fats that are present on the skin of our finger tips..