8 - LV/Mag Equations Flashcards Preview

KMK - Physiological Optics > 8 - LV/Mag Equations > Flashcards

Flashcards in 8 - LV/Mag Equations Deck (14)
Loading flashcards...
1

Relative distance magnification (RDM)

RDM = original distance ÷ new distance

2

Relative size magnification (RSM)

RSM = new size ÷ old size

3

Lateral/geometrical magnification

M = hi/ho = L/L’ = l’/l

4

Hand-held magnifier total magnification

HHM = abs(u)*F

HHM = abs(orig dist bw object and eye)*power of lens

Think HHM, ugh Fuck

5

Hand-held magnifier effective magnification

EM = F/4

What’s on labels, uses standard dist of 25cm

6

HHM linear field of view

FOV = d ÷ (Feℓ)

= diameter of lens ÷ (equiv power*dist from HHM to spec plane)

7

Stand magnifier total angular magnification

TAM = mM

= lateral magnification * RDM

In class we used Enlargement * RDM

8

Stand magnifier + add lens magnification

M = Equivalent power ÷ 4

Max = this + 1

9

Telescope tube length

d = ƒ(obj) + ƒ(oc)

= focal length objective + focal length ocular

10

Magnification of telescope (2)

MTS = -(F(oc) ÷ F(obj))

MTS = diameter entrance pupil ÷ diameter exit pupil

11

Telemicroscope magnification

TMS = M(reading cap) * M(telescope)

12

Telemicroscope reading cap magnification (2)

MRC = abs(u)*F
= abs(orig dist bw object and eye)*power of reading cap
(ugh Fuck)

MRC = F ÷ 4

13

Snellen/M size conversion

Test distance/M = 20ft/snellen

14

Predicting add
-Kestenbaums
-lighthouse

K: inverse of distance BCVA

L: add = (got ÷ need)*WD
WD is in DIOPTERS