Lenses are tools that are all around us from glasses and cameras to your own eye. So the question is how do they work? Converging or convex lenses are a kind of lens that bends light to a specific point. To see how they bend light let’s go to a diagram. In exams, they often use an arrow as the object so let’s do that as we experiment with this lens. As you can see the arrow is currently behind this blinking point which we’re going to call the focal point from now on. There is another one of these equidistant from the lens on the other side.
Converges Lens:
The focal point is where all the light converges. And the distance from this Optical Center of the lens, along the principal axis. Is called the focal length. Anyways, to find out where the object’s image will appear, you have to trace some rays of the light emanating. From the object and See where they intersect. I find it easiest to go from the top so let’s start there: a ray coming towards the lens parallel to the focal end. Will go through the focal point on the other side. A ray coming through the nearer focal point will be parallel to the focal length. Finally, a ray coming through the center of the lens won’t at all. Now we can see where the top of the object is and so we can draw it in. There are a few things to notice about this image. It’s inverted, it’s enlarged and finally, it is real.
Focal Point
Now, the meaning of real images will become clearer once you know. What virtual images but one thing you should. Know that a real image can be onto a screen. That’s what it is if you’re ever asked to give a definition. Next, let’s try with an arrow at twice the distance of the focal point. This time we get an interesting result the Size of the image is actually the same as the object. Besides, it is still inverted and real. This is a consequence of following the rays, as you can see they converge right there. So, in summary, the image of an object at 2F is inverted, is the same size, and is real … it’s still real.
Optical Center Rays
Now, if the object is beyond 2F that is to say beyond twice the focal length, then, as you’ll see after drawing the rays. The image is still inverted and still real but instead of enlarged. Or unchanged in size, which means it’s smaller. , an object beyond 2F produces an image, and that is real. But, this is the hard part if we were then to change the position of the arrow to in front of the focal point. That is to say closer to the lens than the focal point. And repeat our process with the rays again you should notice something different. They don’t converge at all. So it’s clear that the image can’t be on that side but where can it be from? Well, all you have to do is trace back the rays and you should see that these virtual rays.
