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Historically I haven't been that strong in optics, so I tried to find a clever way to deduce all the situations possible. I'll post my method here, and your guys' job is to tell me if there are any pitfalls or errors in my logic. Thanks.
So background information I need to know:
1. Light reflects off mirrors. This means real images are on the same side as the object, and virtuals on the opposite side.
2. Light goes through lenses. This means real images are on the opposite side of the object, virtuals on the same.
3. I breakdown the characteristics of the image into three dichotomies: S(maller) or L(arger); R(eal)or V(irtual); and U(pright) or I(nverted).
[I would imagine all of this sounds familiar because it's in TBR.]
First point:
Diverging mirrors/lenses always produce images that are SUV (smaller, upright, virtual).
Second point, applies to converging mirrors/lenses (and here's where it gets tricky):
1. To find S or L: I associate the image's size as inversely proportional to the radius. So if the object is greater than the radius, the image is Smaller, and vice versa.
2. To find R or V: I associate the image's realness with the object's relation to the focal point. Greater than the focal point = Real, lesser than the focal point = Virtual.
3. To find U or I: it is simply by association. I goes with R, U goes with V.
For example let's say o is between r and f on the left side of a converging lens. The steps I would use to deduce the image are:
1. I compare the object to r: this object is less than r, so the image should be Larger, which carries the implication that the image is farther away from the lens than the object.
2. I compare the object to f: the object is greater than f, so the image is Real, which carries the implication that the image is on the right side of the lens.
3. By association with the previously deduced R, the image is Inverted.
So from those three deductions, I can conclude that the image is RIL: Real (on the right side of the lens), Inverted (by association with R), and Larger (farther from the lens than the object).
By this method I should be able to get through any problem asking about the general characteristics of the image. I haven't found a decent way to remember the nuances of the lens equation yet, so any problem asking for the specific position of the image I've been approaching with this method, and then deducing the answers from there.
Thoughts?
So background information I need to know:
1. Light reflects off mirrors. This means real images are on the same side as the object, and virtuals on the opposite side.
2. Light goes through lenses. This means real images are on the opposite side of the object, virtuals on the same.
3. I breakdown the characteristics of the image into three dichotomies: S(maller) or L(arger); R(eal)or V(irtual); and U(pright) or I(nverted).
[I would imagine all of this sounds familiar because it's in TBR.]
First point:
Diverging mirrors/lenses always produce images that are SUV (smaller, upright, virtual).
Second point, applies to converging mirrors/lenses (and here's where it gets tricky):
1. To find S or L: I associate the image's size as inversely proportional to the radius. So if the object is greater than the radius, the image is Smaller, and vice versa.
2. To find R or V: I associate the image's realness with the object's relation to the focal point. Greater than the focal point = Real, lesser than the focal point = Virtual.
3. To find U or I: it is simply by association. I goes with R, U goes with V.
For example let's say o is between r and f on the left side of a converging lens. The steps I would use to deduce the image are:
1. I compare the object to r: this object is less than r, so the image should be Larger, which carries the implication that the image is farther away from the lens than the object.
2. I compare the object to f: the object is greater than f, so the image is Real, which carries the implication that the image is on the right side of the lens.
3. By association with the previously deduced R, the image is Inverted.
So from those three deductions, I can conclude that the image is RIL: Real (on the right side of the lens), Inverted (by association with R), and Larger (farther from the lens than the object).
By this method I should be able to get through any problem asking about the general characteristics of the image. I haven't found a decent way to remember the nuances of the lens equation yet, so any problem asking for the specific position of the image I've been approaching with this method, and then deducing the answers from there.
Thoughts?
