According to SR, a photon has an equivalent mass of h / c λ where h is plank's constant, c is the speed of light, and lambda is the photon's wavelength. So, at some point the equivalent mass of the photon should be sufficient to cause a black hole. (Using the simplified formula I got something like a 10^ -35m wavelength.) Questions: 1. Can a solitary photon have sufficient energy to become a black hole in GR? 2. If the answer to 1 is yes, is it possible to have frames of reference where the photon is not a black hole -- for example red shifting the photon to reduce it's energy? If so, how does that frame of reference experience hawking radiation associated with the black hole? 3. If the answer to 1 is no, is there some limit to the maximum energy that a photon can have, and can a black hole be disolved by spontaneous massive energy to matter conversion inside the Schwartzchild radius?