Originally posted by Ira Boy, do I feel stupid. More stupid than usual, that is.
Didn't even think about the cropped sensor factor.
don't worry, not even lens makers consider it,.
I have several full frame lenses with tulip hoods, all 3rd party lenses, all in pentax mount when they know pentax only sells cropped sensors, but they dont even have an optional hood optimized for the cropped sensor. the standard lens hoods are almost........ useless
I have a program that I downloaded, called hoodcalc, that can calculate the length of a circular hood, for any lens, knowing the focal length, true lens diameter (not filter ring diameter) and hood diameter.
I have modified it to generate plots of tulip hoods.
Biggest issue is making something more perminant than construction paper