Originally Posted by hersito
its very difficult to calculate a racket head area on your own since its not a perfect ellipse or circle so you might be getting wrong numbers because you are not using the correct calculations.
yah, but why do you think I was assuming that a racket head is an ellipse or a circle?
What I did was to take a picture of a racket next to a shape (like a rectangle or a circle) with a known area in sq inches. Imported that into any decent image editor. In the editor I find out how many pixels the racket head area takes. I also find out how many pixels the known-size area takes. Once I have that it is a simple equation to find out the area of the racket head.
Works pretty well. Just need to be careful to take proper pictures and do some image editing magic to make sure that in the editor the pixels are counted properly.
To be even more sure I usually take pictures of the racket next to multiple shapes with known area. That way I can re-verify the measurements and pixels-to-area equations. Since I know the areas of at least two shapes I can verify if the pixel ratio for those two shapes makes sense (as it needs to be the same ratio as the ratio of their areas).