Originally posted by RickL Thanks. Most of what I use are zooms. I'll try the blower again, and I do have some canned air too, so I'll try that too. Again, appreciate the comments.
As you can see in post #10, someone is stridently against canned air because you may damage something. Personally, I think the propect of damage is greater with a Rocket Blower simply because of how it has to be manipulated to work.
I'm more concerned about whacking a component with the blower tip than I am of spraying propellent onto a sensor.
Having said that, if you are going to use canned gas, be aware that it can spray propellant. It isn't all that cold coming out, genuine Dust-Off is tetrafluoroethane, which has a boiling temperature of -26ºC. However, liquid propellant may well be cold enough to damage the cover glass on the sensor (though I doubt it, I've used my DSLRs in far colder conditions).
If you are going to use canned gas, make sure to do a couple of test puffs away from the camera before you clean your sensor with it, and don't do more than short puffs to ensure you don't boil propellant into the nozzle. Long blasts of the stuff don't work well anyway, as the pressure drops quite rapidly in the can.