2000/12/2 8"/f6 Dob with 9mm eyepiece. Blinking nebula is the small round nebula on the right. The nebula will truly disappear if you stare at the central star (and reappear if you use averted vision). A good example that the fovea of our eyes is insensitive to low light.
Sketch, 1999/11/7, with 8" Dobsonian. Observed from Squirrel Hill, Pittsburgh. Very bright central star. Obvious oval nebula, brighter than the Ring nebula (M57).