Virtual and real image with concave mirror at 45 degrees

[nikosb]

I have a spherical concave mirror with focal length of 65cm, radius of curvature of 130cm. I hold the mirror close to the eye at approximate 45 degrees and I reflect an object below it as shown in the image.

The distance between the object and the mirror is 90cm, that is more than the focal length. In such a case one would expect that a real image would be formed, the real image being inverted. I did a ray tracing diagram and indeed the rays converge to the left of the mirror. However when I look at the mirror I actually see a virtual image that is upright (a little blurry) and that appears to be behind (to the right) the mirror. How is this possible?

I understand that a real image is formed but the eye is located between the real image and the mirror and thus can not see the real image. Instead the eye sees an upright virtual image. What is happening? Isn't this contrary to basic optics law?

 

[sophiecentaur]

Summary:: Image formation with concave mirror at 45 degrees. A virtual image is visible even though the object reflected is at a distance larger than the focal length. How is this possible?

However when I look at the mirror I actually see a virtual image

Your post is hard to make real sense of but I think the problem may be here. On what basis are you concluding that the image you see is virtual?

 

[nikosb]

Your post is hard to make real sense of but I think the problem may be here. On what basis are you concluding that the image you see is virtual?

If I shorten the distance between the object and the mirror to less than the focal length (i.e. 30cm) I see a very similar virtual image as expected. As I increase the distance the image remains upright. Also the mirror is a two way mirror so I can more easily tell that the image is formed behind the mirror. So on the basis that a real image is inverted. The reflection that I see is not inverted, it is upright the same way the virtual images are.

 

[sophiecentaur]

It should always follow the 'mirror' equation
1/u +1/v = 1/f and you'd expect a laterally inverted virtual image (now I come to think properly about it) if the object is close in (like a plane mirror). That equation is a given so there is something different in your set-up, perhaps. Are you sure about your f?
When you say it's fuzzy, where are you looking from? Can you adjust the object distance so that you get the 'exploding image' as it goes through f?

 

[sophiecentaur]

In your setup, you aren't working anywhere near the axis so you may be having some gross aberrations(?). Just a thought. Can you repeat those results when operating near the prime axis?

This sort of thing is so much easier to deal with 'hands - on'. Perhaps a photograph of the actual set up with some idea about the size of the mirror.