| image virtual | <microscopy> A virtual image has no real existence. It is the image seen when looking into a mirror. The field of view of the microscope is a good example of a virtual image. When the eye operates in conjunction with a lens to form an image on the retina, the visual sensation is as if the image existed in space. That its apparent location is very definite is proved when a pin can be made to coincide with the mirror (virtual) image of another pin that is seen by looking at a sheet of glass acting as a mirror. With a lens system a virtual image can be definitely located as by graphically tracing rays back to a focus. In a microscope, if the eye is relaxed as it should be, the virtual image will be at infinity. Measurements show that most observers place the aerial image at 20-25 feet, some as close as seven, because of partial accommodation. (11 Mar 1998) |
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| intermediate image plane | <microscopy> In a light microscope, the plane into which the objective lens directly focuses the image of the specimen. The plane is usually located a set distance (commonly 10 mm) below the shoulder for the ocular and another fixed distance (generally 160 mm) behind the rear focal plane of the objective lens. The ocular forms a virtual image of the intermediate image for visual observation, or projects a real image for photography and video microscopy. Note: The objective lens, combined with the coverslip of proper thickness, is corrected for projecting the primary image to the specified intermediate image plane only. (05 Aug 1998) |
| inverted image | An image formed by the convergence of the actual rays of light from an object. Synonym: inverted image. (05 Mar 2000) |
| optical image | An image formed by the refraction or reflection of light. (05 Mar 2000) |
| tactile image | An image of an object as perceived by the sense of touch. (05 Mar 2000) |
| eidetic image | Vivid mental image in the form of a dream, fantasy, or an unusual power of memory and visualization of objects previously seen or imagined. (05 Mar 2000) |
| electron image | <microscopy> A representation of an object formed by a beam of electrons focused by an electron optical system. (05 Aug 1998) |
| false image | <ophthalmology> The image in the deviating eye in strabismus. (05 Mar 2000) |
| unequal retinal image | A condition in which the ocular image of an object as seen by one eye differs in size and shape from that seen by the other. (12 Dec 1998) |