SALT-for optics

SALT is just a checklist for image characteristics: S → Size A → Attitude (upright or inverted) L → Location T → Type (real or virtual)

Plane Mirror

S – Size:
Same size as the object

A – Attitude:
Upright

L – Location:
Behind the mirror
Same distance behind as object is in front

T – Type:
Virtual

Memory tip:
Plane = SAME

Convex Mirror

S – Size:
Smaller

A – Attitude:
Upright

L – Location:
Behind the mirror (between F and mirror)

T – Type:
Virtual

Memory tip:
Convex mirrors = store mirrors → small, upright images

Concave Mirror

Step-by-step using SALT

T — Type (do this first!)

• Rays meet in front of mirror → Real

• Rays meet only when extended backward → Virtual

On quizzes: usually REAL

A — Attitude

• Real image → Inverted

• Virtual image → Upright

S — Size

Compare image to object:

• Shorter → Smaller

• Taller → Larger

Common cases:

• Object beyond C → Smaller

• Object between C and F → Larger

L — Location

• Real image → In front of mirror

• Virtual image → Behind mirror

Common mistakes

Saying “upright” for a real concave image
Forgetting location
Mixing up real vs virtual
Writing SALT out of order (do T first for concave)