Caclulate object size when I have physical pixel size

Question

How do I calculate the object size when I have

focal length = 25mm distance to object = 700mm CCDs pixel size = 4,4µm ?

My camera is this one. Appreciated!

Edit: Could this work:

real height = (object px height * pixel size * distance)/(focal length) ?

Asked by Wilhelmsen

Answer

Quick mental examination says your formula looks correct.

Almost intuitively:

• Image_height x (Distance/Focal_length) = Real height

  so

• (Pixel_pitch x pixels) x (Distance/Focal_length) = Real Height

Answered by Russell McMahon

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