Images have been made by Nikon Eclipse E 600 light microscope using an original magnification of 400x - 600x range, at South-Transdanubian Emvironment Protection Inspectorate, Laboratory for Environment Protection (Hungary). Photos of algae have been taken from samples of natural surface waters of South-Transdanubian region; the majority originated from river Dráva and lake Baláta. Images have been made by phase contrast setting, whereas a blue color filter has been used instead of a green one recommended by the literature. The reason of the change is that although the green filter gives a sharp image, it reflects the shades of gray color only. When using a blue color filter, the sharpness of the image is barely reduced, but the colors of the object are retained. Scientific names of algal speciei are found in the header of the images.