The highlight on the globe is due to the position of the observer. If the observer lowered to the same position as the light, the highlight would be centered. Draw a picture of the camera, globe, and flashlight (with the camera being over the flashlight).

Have you ever used a sundial? The position is not changed once you set it up. If you live in an area with daylight savings time, you have to account for that or else the sundial will appear an hour off. If you live in an area with no time changes through the year, your sundial will be accurate to within 15 minutes all year long.

Let's do some math. There are 360° in a circle or clock face. There are 24 hours per day. This is 15° to represent one hour. If the shadow cast is 15 min early, or 15 min late at max, this would be 3.75° of error. Like I said that is a very small angle. It would not be a 7.5° (30 min) error because you are measuring the angle between true time and the shadow cast, which does not exceed 15 min.

The highlight on the globe is due to the position of the observer. If the observer lowered to the same position as the light, the highlight would be centered. Draw a picture of the camera, globe, and flashlight (with the camera being over the flashlight).

Have you ever used a sundial? The position is not changed once you set it up. If you live in an area with daylight savings time, you have to account for that or else the sundial will appear an hour off. If you live in an area with no time changes through the year, your sundial will be accurate to within 15 minutes all year long.

Let's do some math. There are 360° in a circle or clock face. There are 24 hours per day. This is 15° to represent one hour. If the shadow cast is 15 min early, or 15 min late at max, this would be 3.75° of error. Like I said that is a very small angle.