A decent camera shop will do a sensor clean for about £30-£50. Some do same day (expect to pay more). That way, they take all the risks, so worth it as a once-a-year-or-so cost when weighed against the cost of a new sensor.
Anyway, unless things are really mucky, I'd just use the clone stamp to get rid of marks.
And take steps to prevent dirt getting in in the first place! One of the main causes is changing lenses without turning the camera off. The sensor carries an electrostatic charge that acts, quite literally, as a dust magnet.
Changing lenses in a wind, when it's raining, on a beach, at a concert where they use a smoke machine (the smoke is oil based) are all really good ways to make your camera work worse:shrug:
Good advice about when best to change lenses Jon, especially about the smoke.
While getting someone else to wet clean the sensor may be a good idea, it is also very expensive. For the same amount of money you could buy the gear for 12+ cleans done by yourself.
It looks scary, though it is reasonably easy. When I had to do it in the past, the mistake I made was to drag the sensor swab against the edge of the sensor box which made it a hundred times worse, as the lint free material suddenly shed loads of material. Two or three more attempts and the sensor was perfect.
You only make that mistake one.
There are many videos on the the net to show you how to do it, should anyone want to do it for themselves.
you are half right - "when the blower stops , and gravity overcomes the force exerted on the dust by the blower , gravity will make it fall down - however in the period in which gravity does not overcome the force exerted it will keep moving in the same direction as the air
think of throwing a tennis ball up into the air - if oggy (and newton) were wrong it should fall down as soon as it leaves your hand.
more prosaicly you are also mostly right that rocket blowers are useful bits of kit - but there are occasions when they make the situation worse by blowing dust that wasnt on the sensor on to it.
Not to labour the point too much,
but even though the air may initially be travelling in one direction, the air is entering the dead end (so to speak) of the sensor 'box' which I would imagine causes all kinds of vortices as the air entering and that being reflected out interact.
As a test, take a tiny bit of paper from the corner of a sheet, and put it in your cupped hands, and then blow. More often then not the paper 'jumps' out of your hands. And this is a large object, compared to dust, and the force of air is less than can be produced by the blower.
With my current camera the sensor shake is working extremely well, (shaking it at start up, and shut down) and I haven't needed to use the blower in the year I have had this camera, or indeed used the sensor swabs which I have bought 'just in case'. It's only a matter of time though.
)
