Which magnification compares the ratio of the original retinal image size to the retinal image size when the object is viewed through an optical system?

Which magnification compares the ratio of the original retinal image size to the retinal image size when the object is viewed through an optical system?

• A. Lateral magnification
• B. Angular magnification
• C. Object-to-image magnification
• D. Image magnification

Answer: (B)

Angular magnification is the ratio used to compare how large the image appears to the eye through an optical system versus without it. The retina basically encodes size by the angle the object subtends at the eye, so the retinal image size scales with that angular size. When you view through a magnifier, the object is seen under a larger angle, producing a larger retinal image even if the object’s actual size hasn’t changed. Lateral magnification, which compares image height to object height in the image plane, describes linear enlargement in the optical system itself—not how large the image appears to the eye. So the best term for comparing retinal image sizes via the eye’s perception is angular magnification.

Angular magnification is the ratio used to compare how large the image appears to the eye through an optical system versus without it. The retina basically encodes size by the angle the object subtends at the eye, so the retinal image size scales with that angular size. When you view through a magnifier, the object is seen under a larger angle, producing a larger retinal image even if the object’s actual size hasn’t changed. Lateral magnification, which compares image height to object height in the image plane, describes linear enlargement in the optical system itself—not how large the image appears to the eye. So the best term for comparing retinal image sizes via the eye’s perception is angular magnification.