Originally posted by GerryL Soldbear, with the step-down rings, won't the photos vignette?
Won't it cause some sort of a tunnel vision effect?
Some lenses do, some don't.
I set the camera in Av mode and open the lens to full aperture, then I add step down rings until I see a drop in shutter speed, then I back up one step.
For this Vivitar 135mm close focusing (62mm filter thread diameter), for example, I have to stop at 49mm, then I add a Pentax 49mm lens hood. It's still more compact than a 62mm lens hood.
I found out that this kind of "lens hood" doesn't work well with zoom lenses.