How do I clean deposits off camera lens?

[rickcavanaugh]

Not so high in Ca only about 400 PPM (parts per million). As for pH most likely places you dive, the pH is about 8.0 or so down quite a bit in the last 40 years. GO to Composition of seawater and you can see data on mineral compositions, as well as pH around the world. In any case, even at pH 8.3 it is not highly buffered so its corrosivity is quite limited to most optical glass (thankfully)

Bill

400 ppm calcium is high when you let it dry on your camera without rinsing. Calcium deposit will occur.

You will also notice the healthiest reefs are in areas with higher pH levels. If you are diving in the pacific and you see xenia pumping, the pH is close to 8.3. It will not pump in lower pH levels. Yes, there are quite a few areas that are lower. Water will react with the C02 lowering the pH. This occurs more on the surface in unhealthy reefs. Healthy reefs with good plankton growth should be higher or you will soon need a new place to dive (which is happening). For those less scientifically inclined, the difference in pH of 8.0 to 8.3 is about 3 times more OH ions. The pH scale is a negative log. A small change is significant to the health of the water.

Regardless, these factors combined with the high salt levels are the reasons why you keep a wet camera wet and rinse well in fresh water and dry afterwards. As the water dries on your camera, all of these chemicals are left behind in the form of deposits. All of these deposits are not good for optics or the orings/seals.

I have owned and used 4 different housing /camera settings and I have no floods ever over the last 10 years of taking photos. I rinse very well after every dive.

1 glass subal port was damaged from lack of good fresh water on Little Cayman several weeks after it was hit by a major hurricane, got etched from the salt water drying on the port without proper rinsing.