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There are a lot of posts regarding real vs virtual images. I 'think' I understand the distinction clearly, however, there is one thing that I can't quite wrap my head around. What is the "shape" or apparent shape, of a virtual image?

I understand that I can photograph a virtual image because a real image is eventually formed on the sensor. I am not sure what it means for a camera to focus on a virtual image though.

I assume that a virtual image from a mirror, will remain the same proportion to the object, but if a virtual image is formed from a lens, does it become "curved"?

In case I'm not asking the right questions, the very specific use case that I'm trying to understand is a camera in a underwater housing, looking out a curved glass port into water. Everything I have read states the camera focuses on a virtual image that and that the virtual image is curved.

However, all of the lens examples I've found show 2 dimensional - if the image flipped, where it's located, and it's magnification. From that, I don't see how I could determine if a virtual image is curved. Can anyone help guide me to what I'm missing here?

Thanks!

g3cko
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1 Answers1

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To give a simple answer: a virtual image has the same shape as it's 'real' counterpart (up to magnification and flipping, maybe) - the only difference is that a real image is located in a region in space you can touch, i.e. you can put your hand where the image is forming.

A virtual image is an imaginary object that appears as if the rays of light you are seeing are originating from it.

The good example is a mirror hung on a wall. The light rays reflected from the mirror are such that they seem to originate from a region inside the wall, but you realize that there is no such region - they just appear that way.

On the other hand, a projector (like in the cinema) it a good example of a very real image you can 'touch'.

Cardinal Sine
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