Explain why an image formed on the screen of the pinhole camera is inverted. What does this show?

Answer 1

Suppose object is on the left hand side of the screen you are viewing, the pin hole is in the middle (center)

If a ray (straight line) starts from top of the object and passes through pin hole in the middle then it will meet the right hand side of the screen at the bottom .

Thus top of the object will become the bottom of the image on the screen on right

Similarly a ray starting from bottom of the object and passing through pin hole in the middle will meet the right hand side of the screen at the top

The bottom of the object will become top of the image


This shows that LIGHT travels in straight line .

Answer 2

An inverted image is real and can be projected on a screen. The reflected rays actually meet at a point where the image is formed.
Go to the website below to find the explanation. The diagrams shown will help you understand image formation.

http://www.physicsclassroom.com/Class/refln/reflntoc.html

Answer 3

Basically it shows that photons fly in a straight line and spread out like a wave front from a point on the object. Assume the projected object is an all-day sucker, with the round candy head up and its stick down. The head is above the pin hole and the bottom of the stick is below it.

Thus, as photons fly in a straight line from the bottom of the stick, the photon that gets through the hole is flying in a straight line angled upward toward the hole. All those photons with smaller, lower angles will impact the cardboard the hole is punched in. They will be blocked.

Similarly, any photons from the bottom of the stick flying out at larger, higher angles to impact above the hole will also be blocked. As a consequence, only the photons that carry the image from the bottom of the stick and through the pin hole show up on the screen. But the bottom is now on top because of the positive, upward sloping angle needed to fly through the hole and not be blocked out.

In like fashion, the candy top also has a critical angle that allows the straight flying photons to get through the pin hole. Photons streaming out at other angles will be blocked. As a result, the candy head image is now below the pin hole level; it is inverted. So, the inversion shows that the photons hitting the screen traveled in straight lines from the object. What about the wavefront characteristic?

Now move the all-day sucker up and down relative to the pin hole position. The inverted image will remain intact on the screen despite the obvious changes in critical angles. This suggests there are photons coming off at other angles besides just the original critical angles.

For example, moving the sucker up a bit relative to the hole, commensurately lowers the original critical angle from the bottom of the stick . Yet the bottom of the sucker still shows inverted on the screen. Thus, there were photons coming off the original critical angle and also now, after the move, off the new, smaller angle.

Conversely, while the bottom of the stick critical angle is now smaller, the candy head critical angle is now larger. The net effect, is that the inverted image moves down on the screen while the object moves up.

Keep moving the sucker and you will find photons coming off it and showing up on the screen with a wide interval of critical angles. You can get the same effect by moving the sucker side to side; that is, the image will still be on the screen and it will move opposite to the direction of the object. So we can conclude photons come off that sucker at all angles from each illuminated point of the object. Thus, the wavefront of photons that spreads out like part of a sphere from each point on the sucker.

Answer 4

You should draw a picture (side view) of an object, the pinhole and the inverted image. This illustration should explain everything.

Answer 5

It forms an image of whatever colors are present in the object.