[QUOTE=marciofs;1495939]This two images were taken with a 0.420mm pinhole and the same time exposure 25min.
Do you think the flare is actually UV light. If I use UV filter does it solve this flare problem[QUOTE]

My first guess would be light reflections inside the camera. Did you paint the inside matt black and cover the metal of the pinhole with black tape?
Or did you take the photo into direct sunlight? I supose you don't have light leaks?