Digital pollen allergy
One of the bad things about DSLR (aka Digital Reflex) cameras is the tendency to get dust in the image sensor (as these cameras use removable lenses). Whether it is just dust or pollen it may eventually be shown in your photos (like the spot I show on the right: it is just blue sky).
For not so big spots, they may go easily undetected. If you want to check for dust in the sensor the simplest way seems to take a photo of the blue sky with the smallest aperture possible on your lens (F22 in my case).
Detecting the problem only serves to make you nervous, but fear not, it can be fixed. There are different ideas and people who would talk for or against any of them. I do not feel comfortable risking my camera sensor without reading quite a lot before doing one thing or another. Apparently there are several ideas that can help:
- Air blower.
- Dry dust removers.
- Wet dust removers.
- Send the camera to the manufacturer for a professional cleaning of the sensor.
I'm still in the process of trying one (or more) of the above methods to get rid of my sensor dust. For the moment I think my camera just has Spring fever :-)