What is the cause of the annoying concentric ellipses in the center of this image? It happened sometime while I was developing the film. It occurs on some other images of that roll. Can they be removed? If so how? I have just started developing my own negatives for the first time in forty years. It's like starting all over again. Whew! The film is Tri-X Developer is D-76 I used an eco-friendly stop bath Kodak fixer A good wash Fixer remover Another good wash Photoflo All working solutions were absolutely correct and timing was meticulously followed. I used well water with some mineral content for washing only but the final wash was followed by a rinse with distilled water.