Quote Originally Posted by Duane Pipe View Post
A bit off topic. Before I leave home I put the lens on that I think I will use most for the outing, In a sterile place.

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Dave! You're kind'a wasting your time and efforts really .. here's why.

Changing lenses in itself is not really how or why the sensor collects dust onto itself.
The dust particles it collects are smaller than the small floaties loitering within the camera's mirror box assembly.
The dust specks are usually of a finer/smaller size than the stuff that settles in the mirror box area.
The dust that collects onto the sensor does so due to electrostatic attraction, that is, as the sensor is on, or operating, it has a charge around it that attracts dust specks.
The dust specks are smaller and more easily attracted to the sensor, whereas the larger particles usually fall onto whatever surface they can.

For the vast majority of its time, the sensor is actually well protected from the ingress of dust, even when changing lenses.
That is, you can easily change lenses in a dusty environment and not get dust on your sensor at all!
The fact that is well hidden and isolated behind a shutter is quite an important point to understand about this.
That is, if the shutter is not going to protect the sensor against massive dust particles, how is it expected to provide a light tight seal for correct exposure?
(photons are much smaller than dust specks!!)

What invariably happens is that dust does get into the camera body, and you can do all you like and take all the necessary precautions to minimise this, but the fact is that most dust gets into the camera chamber via the lens .. especially zoom lenses.
Very few, if any, are completely sealed from the miniscule particles of dust.

I haven't actually tried this myself, but I'm pretty sure that the Nikon 105VR lens is weather sealed to a degree. Maybe not entirely, but close to it, as it has a rubber sealing ring on the mount.
But the only real way to know for certain how dust gets onto a sensor is to do a long term trial using an unsealed vs a sealed lens test.

of course it's always better to be cautious when changing lenses, but don't be overzealous about it!
The chances are that it's the common every day usage of the camera that will attract dust to the sensor .... it's inevitable for a partially sealed camera design.