The size of the spots and the time of year they occur can usually give you an idea of the cause of the problem. If the camellia is under pine trees the spots could be caused by pine needles dropping on tender young leaves and bruising them. The spots are usually less that an eighth of an inch. Sap dropping on leaves can also cause spotting. Scrape the surface of the leaf to see if you can remove the spot. Check the back of the leaf to see if there could be an insect puncturing the back of the leaf and producing a spot on the leaf surface..
Not under any trees, but faces northwest. Gets late day sun and that may be too much. Will check the leaves closer tomorrow in daylight.
If the spots are small and a reddish brown, Anna, your camellias could have a nutrient deficiency.