Sensor spots?

[rajah sulayman]

I was doing my monthly sensor-clean earlier and noticed that the random spots I see on my sensor appear to be consistent and unaffected by cleaning. From what I can tell, they don't really affect my shots (even when taking test f/44 shots into the blue sky), but I'm wondering what they are and what causes them.

Below is a brief animated gif of my sensor shots before and after cleaning. If you notice, the dust moves/cleans, but the spots remain.

What are they?

http://www.focalmatter.com/misc/sensor.gif

For reference, I don't use any liquids when cleaning my sensor (even "approved" ones). I just use a pec pad on an angle-cut rubber spatula (very basic, but works wonders).

[Woolburr]

Add a drop of the approved liquid and watch the rest of the spots disappear. Looks like the sensor was swabbed with a very wet swab at some point. 1 drop is all you need.

[rajah sulayman]

So I just drop the liquid directly onto the sensor and let it evaporate?

I've always been afraid of streaking or leaking (which is why I've avoided it), but I guess it's made specifically to prevent that from happening.

[Woolburr]

No...you put one drop on the pec pad and give it a swipe...check it...if needed use another drop on a clean pec pad...repeat until the spots are gone...just keep using a clean pad and only one drop of fluid.