Do not confuse r, the distance to the center, with R, the radius of curvature of the light. Now let us consider a black hole. You can easily find the r for which the light is in circular orbit around the black hole. Another goofy thing is the slowdown of time in a gravitational field. This causes what is known as the gravitational red shift.
Time is slower in the high gravitational field of a star, so light frequencies are lower.
The same is true of the photon, although this is not the conventional way of looking at it. Gravity does not slow down the photon, but if you replace v with c in the equation for the minimum speed of the bullet, you get the relationship between the mass and maximum radius of a black hole. Red is the lowest visible frequency, so this is called the gravitational red shift. The maximum D f is f, then the frequency is zero and the photons have lost all their energy and would cease to exist. There is another red shift caused by the Doppler effect, not an application of general relativity.