I had a bad feeling before doing it but it had become inevitable. There was more dust on my Canon 5D’s sensor than under the bed and it needed cleaning. And indeed it was a bad start into last week when somehow some of the cleaning liquid was leaking into the sensor – right in the center – leading to a nice visible colored stain in the photos. I had wanted to upgrade to a 6D in a long time anyway, but it seemed to be a bad time as just a few days ago it was announced that Canon had …