Spring Cleaning

Its the first day with a really clear sky I seen in a while and a perfect time to check on the cleanliness of the sensor on my sensor. I wrote some time ago about DSLR’s dirty little secret and how to use a photo of the clear sky to detect the presence od dust on the sensor. My current Pentax D20 is a well engineered unit and includes a dust reduction, a dust detection and a dust cleaning system (it shakes the sensor, with the mirror lifted). However small dust particles always seem to be get into most cameras. So I regularly check using my blue method. Now I additionally slide the highlight and shadow bars across while zoomed in to help detect dust. Ok often its barely visible (And not seen by the Built-in dust check) but I now know it there. Generally just one or two runs of the dust removal procedure followed by another blue sky photo is enough to convince me my camera is clean.
On my Pentax dust removal involves taking the lens off holding the camera facing down and selecting the dust removal from the setup menu, the whole camera appears to shake for a couple of seconds, that's all it takes. Older SLRs, which don’t shake themselves, can be cleaned by selecting the mirror up and using clean air blasts (you can buy specialty air-pressure pack from a camera store or use an old fashion bulb blaster, just take off the brush) across the sensor area. It is important not to touch the sensor or mirror directly with anything.
WARNING some camera manufacturer/models, notably many Nikons, claim such air blast cleaning voids the warranty and you need to get a certified dealer to clean the sensor (check your camera manual)