Look through your image collection and try to find one containing dust shadows and another with polygon flare. If you can’t find examples of each use the images provided in the key resources of the student website.
I’ve had a few occasions where I’ve had dust on my sensor that has shown up on my images. Luckily the images have only shown up in areas where there was no detail such as a white wall or blue sky, not where there have been other detail, as I feel that you might not necessarily notice this unless there are a lot of dust spots. I’ve had experience of using the clone stamp tool previously to remove dust spots so haven’t replicated the work here. Hopefully with cameras that have a dust cleaning action built in and experience of cleaning the sensor, dust spots will be reduced and then post processing won’t be needed.
I didn’t have any examples of polygon flare in the image as I tend to try and position the sun so that its lighting the image face on or from the side, not directly and I also use a lens hood to try and remove this from affecting the images. My preferred way of working would be that I’d try to avoid flare in the images as opposed to trying to rectify later on.
Note: A couple of days after I wrote this, I actually ended up with an example of polygon flare with some early morning sun. Keen to keep the image, I followed the guidance of using the clone stamp tool on colour to move the brightness more to what it should be, and I then used the clone tool set to darkness. I felt that it still needed something else so I used the enhance –adjust lighting-shadows and contrasts to just darken the bright image slightly and to help disguise the work I’d undertaken.
Original Image with flare