# Revising simple lenses - magnified, and diminished images

• RK1992
In summary, the conversation is about revising lenses and understanding how to determine if an image is magnified or diminished. The diagrams on pages 6 and 7 of the AQA-2450-W-TRB-OGA.PDF provide examples. The speaker also mentions being able to do the geometry of an object at different points to determine if the images formed are real or virtual, inverted or upright, and magnified or diminished. However, they are unsure about the meaning of image distance and how it affects the size of the image. The speaker also mentions the complication of including the eye, which contains a lens, in the problem and suggests using a second lens to determine what the eye will see.
RK1992
Basically, I'm trying to revise lenses and the one thing I never really understood was how to tell whether an image is magnified or diminished.

http://store.aqa.org.uk/qual/gce/pdf/AQA-2450-W-TRB-OGA.PDF pages 6 and 7 has the diagrams to show what I mean

I can do the geometry of an object at points where:
O.D. > 2F;
O.D. = 2F;
2F > O.D. > F and
F > O.D. > 0
to show that the images formed are real/virtual, inverted/upright and magnified/diminshed but I'm not really sure what the image distance means.. if the image is diminished but the image is nearer to you, how do you know whether it would appear bigger or smaller? Likewise with a magnified virtual image which is further away than the object.

Thanks

I am not positive but it seems like your intuition about a magnified image being far from your eye mean that is would not be as magnified. The one thing I will say is that things a more complicated when you include your eye because your eye contains a lens. So, now you have two lenses in the problem. The magnification of the images in question are in relation to that single lens. If you want to figure out what your eye will see then you need to work through with a second lens.

## What is the definition of a simple lens?

A simple lens is an optical device that is made up of a single piece of glass or other transparent material with a curved surface. It is used to refract light, causing it to converge or diverge in order to form an image.

## How is magnification determined in a simple lens?

The magnification of a simple lens is determined by the ratio of the size of the image to the size of the object. It can be calculated by dividing the image distance (distance from the lens to the image) by the object distance (distance from the lens to the object).

## What factors affect the magnification in a simple lens?

The magnification of a simple lens is affected by the curvature of the lens, the distance between the lens and the object, and the distance between the lens and the image. It is also affected by the refractive index of the lens material, which determines how much the light is bent as it passes through the lens.

## How is an image magnified in a simple lens?

In a simple lens, an image is magnified when the object is placed closer to the lens than its focal length. This causes the light rays to converge and the image to appear larger than the object. The greater the distance between the object and the lens, the greater the magnification of the image.

## How is an image diminished in a simple lens?

In a simple lens, an image is diminished when the object is placed further away from the lens than its focal length. This causes the light rays to diverge and the image to appear smaller than the object. The closer the object is to the lens, the smaller the magnification of the image.

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