Pity the fool who likes to change lenses in the middle of blowing sand.
Finally decided to take a closer look at where and how many dust spots might be plaguing the sensor on my 60D. Hadn't really noticed it all that much until I started using Nik Color Efex "detail enhancer" which made some so-so images pop, but also made grey, high contrast skies explode with spots. Looked as bad as the time I used a Conkin filter in a storm, and thought I had dried it off, but left water spots that showed in the next photos I took using it. The solution there was to wash each filter with soap and water, and dry carefully with micro-fiber towels, making a mental note to to remember to do this if I use ND grads on a wet shoot.
If only the sensor were as easy a DIY fix.
To check the sensor I followed a suggestion I found on the Canon info bank site that suggested shooting a plain white piece of paper stopped down as low as possible, then view it at 100%. I went the extra step of running it through Color Efex and fiddling with contrast and black and white settings to make each mote pop like it did on the pics that I first noticed it on. After counting close to 50 distinct spots I wept.
It's all too obvious that I like to work in crap conditions (e.g. blowing sand, mist, storms) and that I like to change lenses a wee too often. Having come into enough money to be crazy-mad-boy and order a new 5D MkIII, -the 60D becoming my backup body- it's also obvious that I'm going to have to come up with a better plan on how to change lenses without developing sensor acne to such an extent. Blowing air with a Rocket didn't change anything, so once the 5D comes, the 60D will be off to Canon for a pro sensor cleaning. And I'm going shopping for an old fashioned changing bag like I used to use to swap out half shot film canisters in order to change ISO in the field. The trick will be to find a lint free one, or have one custom made out of micro-fiber. Will post when I come up with an actual solution.
Follow Up: Got a changing bag only to discover that I'm going to have to modify it for this to work. Need to figure out how to put in an small transparent window so I can see the alignment marks on the body and lens. It is possible to do it by feel, but it's neither efficient or comfortable.