Experimenting with a Diverging Lens: Discovering the Focal Point

[SwAnK]

Hey all, I recently did an experiment using a diverging or convex lens, to produce different images according to the focal point. For the experiment I found the focal length, and set up the lens and light source at that distance. I used just paper for a screen to produce the real images created.

MY question: How could you do this experiment with a diverging lens?

Could you not do the same thing set it up in that manner, and place the lens at different spots according to the focal point? and when its infront of the focal point it produces an upright virtual, smaller image right?? just checking.

thanx!

 

[Jameson]

Is this a double convex lens, because a convex lens is a converging one, not a diverging one.

As for the experiment. You could as a experiment make all of the predictions of what kind of image would form at different points by your lens equations and then check them manually.

 

[SwAnK]

no like double concave, yes that's basically what i did for the converging lens, but would the same process i used work with double concave?

 

[eax]

With the same experiment you can't do that with a divergin lense because a diverging lense will not produce an image on a screen so you can't find the focal point that way. This is based on my knowledge, I recently finished this unit(a month ago) and mixed up 'diverging' and 'converging' on my test so I mostlikely wrong.

 

[OlderDan]

Hey all, I recently did an experiment using a diverging or convex lens, to produce different images according to the focal point. For the experiment I found the focal length, and set up the lens and light source at that distance. I used just paper for a screen to produce the real images created.

MY question: How could you do this experiment with a diverging lens?

Could you not do the same thing set it up in that manner, and place the lens at different spots according to the focal point? and when its infront of the focal point it produces an upright virtual, smaller image right?? just checking.

thanx!

As others have noted, you cannot form images from the diverging lens on a screen. These images are referred to as virtual images because the light never gets to where these images are located. Instead, light is made to appear as if it were originating at these images. One way to locate these images is to use parallax. You need to use an object that you can see outside the edge of the lens that you can place the same distance from the lens as the virtual image. You know they are the same distance from the lens if moving your head from side to side leaves this object and the virtual image aligned. You can then measure the distance of the object to find the image distance.