Originally Posted by
Steve6443
Aircraft registrations are INTENTIONALLY large enough to be read from distances further than the limits of Rule 5. Depending on the type of vehicle spanner was driving, the shape of most windscreens dictate that objects above vehicle roof level must be a considerable distance away, horizontally, before they can be seen from behind the drivers seat. This horizontal distance then introduces several "curve-balls" to anyone bold enough to believe they can accurately measure the height/altitude of the object being viewed. Some are mentioned above..........
Also, we shouldn't forget that the brain has excellent cognitive powers. If you see a car a couple hundred metres away, you probably won't be able to read the registration plate. However if you see something on the car which is unique - for example, some stickers, or accessories which denote the car as a particular example known to you, your mind WILL be able to identify that car before you can read the registration plate.
The same thing could have happened here - you saw the plane, you knew the colour scheme and type and what for most people would have been a jumble of letters is, for you, as clear as day because your mind can recognise and unscramble the letters rather than being hieroglyphics at distance for the person unfamiliar with that aircraft leading to your assumption, I saw the registration hence the plane was low. Try it at a club, you'll find you can recognise the registration of aircraft known to you further away than aircraft visiting the base for the first time because, with familiar aircraft, your mind forms the smears into visible letters.....
This is how road signs are designed. Clever really