Lenses Flashcards
Do rays con/diverge for concave/vex lenses?
concave lenses diverge, convex lenses converge
What type of img do you get w/ convex lenses?
inverted real img
What happens if img at focal point of convex lens?
no img
What happens if img behind focal point of convex lens?
real, inverted, bigger
What happens if img at 2nd focal point of convex lens?
real, inverted, same size
What happens if img behind 2nd focal point of convex lens?
real, inverted, smaller
What happens if img in front of focal point of convex lens?
virtual, upright, bigger
What happens if img is in front of focal point of concave lens?
virtual, upright, smaller
How to find power of lens?
D = 1/m (D = Diopter)
Pos/neg di vs do mean what?
Pos = opposite side of lens from light source (ie. real), neg = same side of lens as light source (ie. virtual) vs pos = same side of lens as light source, neg = opp side of lens as light source (extremely rare)
Are real/virtual imgs pos or neg distance?
Real = pos distance, virtual = neg distance
True or false: diverging lens ALWAYS give virtual img
True
Pos/neg f and r mean what?
Pos = converging lens (ie. convex) Neg = diverging lens (ie. concave)
Lensmaker eqn for thick/real lenses
1/f = (n-1)(1/r1 - 1/r2)
n=refraction index
r1=radius of curvature for first lens, r2=radius of curvature for second lens
What does M tell you?
+ = upright, - = inverted; abs(value) < 1 —> smaller, abs(value) > 1 —> bigger, abs(value) = 1 —> same
If you have multiple lenses, how do you find total f, P, and M?
For f and P, add em up (1/f1 + 1/f2 + … 1/f_n; P1 + P2 + … P_n)
For M, multiply (M1 * M2 * … M_n)
Spherical aberration vs chromatic aberration vs dispersion
Blurring of periphery due to inadequate reflection of parallel beams at edge of mirror or inadequate refraction of parallel beams at edge of lens vs dispersive effect within a lens vs when various wavelengths of light separate from e/o (ex: white light splitting into different colors thru a prism; this can happen during diffraction or refraction)
