At 12:47 PM 2/8/2007, Robert asked:
><snip>
>The main reason I would wait for the next release is for the self cleaning
>sensor. Does anybody have experience with it? How well does it work?

I've had experience with the Olympus E-1 and the 5D. The effectiveness
of the E-1 is in part, keeping the dust further from the sensor, such that
the shadows cast by the dust are less sharp. Hence it appears that the
dust shakers work, in part because the dust is held further from the sensor,
which is easier to do on non-FF sensors. (This applies to really fine dust)
The F-stop needs to be F-11 or higher before the fine dust is an issue
(macro photography suffers the most from Dust issues).

Second, the DOF required for a FF sensor is smaller (higher F-stop)
than a reduced frame sensor, and hence will sharpen the dust shadow.

Third, the most difficult dust (or oil or contaminants) are the really small
ones that seem to be un-affected by the shaker. To be most effective
some sort of ionizer needs to discharge the static charge or no amount
of shaking will eliminate the fine dust.

On the 5D, the worst dust occurred, for me, during the summer when
I fired the camera after it had been sitting in the hot car. I believe that
oil from the shutter splattered onto the sensor, and only some sort of
solvent would remove it. I also have a permanent dust particle from
manufacturing, as it is between the sensor and the AA filter.

For the random large dust, the dust shakers help, but so does a
CO2 Duster, for that type of dust. Both the E-1 and my 5D required
cleaning for the fine particulate, which shows up at high F-stops.

For those who want to see the dust in their cameras, set the F-stop to
at least F22, or the highest it will go. Then take a photo, Un-Focused at 
a blue monitor background, or blue sky, or any uniform light. Then boost
the contrast of the image. Dust in the image that is upper right, will be
in the lower right as you look into the camera from the front (if you are
trying to wipe or clean the sensor).

Again, the hardest dust to remove will appears as fine specs. Larger dust
tends to be fibrous and many techniques can remove it fairly easily. The
fine stuff is really difficult for the shakers without some sort of ionizer
to discharge it.

Some links:
http://www.bythom.com/cleaning.htm
http://www.pbase.com/image/15473243
http://americanrecorder.com/catalog/index.php?cPath=10
http://www.fovegraphy.com/IonizerE.php

My favorite method uses a PEC*PAD wrapped around stiff plastic
(like old credit card) with some methanol (eclipse). Cut plastic to
nearly the width of the sensor.

I've tried the VisibleDust brush, the SensorSwab, the CO2 Duster, and
the PecPad on plastic with methanol. The CO2 duster and the PecPad
works the best for me. I have yet to try the ionizer approach. And I just
can't seem to the the VisibleDust brush to do much, at least for the
fine particulate.

If you do macro photography (or any high F-stop), dust is a real pain.

Wayne S 

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