What are the linear features on this print?

 

 

  This is an enlargement of a portion of a photograph taken about 1977 by an amateur photographer Ryan Atwell, who was a fellow tenant in the Atherton mansion I lived in for 9 years. This photo was one of several taken simply to use up the rest of a roll of film during a visit to downtown San Francisco. Upon developing the roll a pair of odd dark lines appeared within the image area. He brought this print to me and asked me what I thought it was, my initial interpretation was a pair of out of focus wires near the camera or perhaps even a pair of fine hairs within the camera itself casting shadows on the film. The problem with these interpretations is shown in this enlargement of the place these two 'lines' disappear behind, and INTO buildings. He claimed the negative was sent to the FBI for interpretation, and that they lost it. A few years later the chronically depressed Ryan, who had since moved into an apartment, committed suicide.

This print has been carried around in boxes for nearly a quarter century, and I present it on my site to invite any ideas as to what we're seeing. I make no claim that this is a real object, simply that the photo is shown truthfully. The above enlargement was contrast enhanced but no retouching has otherwise been done. Although my background in art and visual effects provide the means for some juicy hoaxes, I have not retouched this image beyond providing the contrast enhanced inset. I welcome any suggestions of what these lines on this image might be. There may be similar examples with simple explanations well known to many who develop and print black and white photos. Numerous wrinkles and stains are evident in the print. Here is the entire print, at normal contrast, with the enlarged area above superimposed on an otherwise featureless area of the sky. As you can see, the edges of these features are fairly sharp, and they are translucent, with no apparent cast shadows.

  Some might be tempted to interpret this as a 'rod'. 'Rods' are purported to be unseen transient swiftly moving 'streaks' occasionally caught in photos, usually spotted upon later inspection but not at the time of exposure. In my opinion this school of thought is just a step above UFO lore, I consider this simply as a mystery image which is worth explaining. One must not let skepticism blind one to genuine mysteries which might randomly appear. Don't throw away those pictures taken to finish a roll without careful inspection!