Converging lens experiment

[jnimagine]

hi i posted the same sort of question a few times before but this time it's a little different
we did an experiment with a converging lens and a candle to find an image. When the candle was placed at the focal point, which was 16.3cm, an image appeared at 136cm. I know in theory, no image should be appearing here. Last time when i asked the same question but with concave mirrors, some of the answers i got were that it was caused by the 3-D of the candle and spherical aberrations. But spherical aberration is not likely have caused it because the mirror was too small to cause that. So my question is, is it the same for a converging lens? the reason an image appears there is because of the three-dimensionality of the candle?

 

[OlderDan]

All the same principles apply to a converging lens that apply to a converging mirror. It seems very unlikely that this is purely a 3-D effect. Some of the flame would have to be more than 18cm from the lens to get a sharp image at 136cm if the focal length is indeed 16.3cm. Some distance measurement is probably a bit off, but that's the way real measurements are, subject to a certain amount of error.

 

[kyle8921]

Thank you for sharing your experiment with us. It is always interesting to see how different setups can produce unexpected results.

Based on your description, it seems that the image appearing at 136cm is due to the three-dimensionality of the candle. This is known as the "real image" of the candle, which is formed when the light rays from the candle converge at a point beyond the focal point of the lens.

Spherical aberration is not likely the cause in this case, as you mentioned, since the lens you used was too small to produce this effect. However, there are other factors that can contribute to a distorted image, such as chromatic aberration or astigmatism. These are caused by the lens not being perfectly symmetrical, and can result in a blurred or distorted image.

It is also possible that your experimental setup was not precise enough, leading to some errors in the measurements. I would suggest repeating the experiment multiple times and making sure all the variables are controlled to get a more accurate result.

Overall, the image appearing at 136cm is most likely due to the three-dimensionality of the candle and not any aberrations of the lens. I hope this helps clarify your results. Keep up the good work in your scientific explorations!