Isihloko mayelana nokwakheka kwesithombe ngelensi ehlanganayo (eqondile)
Ukuze uqonde ukwakheka kwesithombe ngelensi eqondile, funda izibonelo zezinkinga nezixazululo ngezansi. Kulesi simo, into ithathwa njengebanga elithile ukusuka kulensi eqondile,
bese udweba ukwakheka kwesithombe ngelensi eqondile, ibanga lesithombe ukusuka kulensi eqondile kanye nokukhulisa isithombe ngelensi eqondile.
Ilensi eqondile inobude obuqondile obungu-20 cm. Izinto ezinobude obungu-10 cm zitholakala ngakwesobunxele selensi. Nquma ibanga lesithombe, ukukhuliswa kwesithombe kanye nokuphakama kwesithombe, uma:
a) ibanga lento kusukela kulensi eqondile lincane kunobude obuqondile belensi eqondile (do < f),
b) ibanga lento ukusuka kulensi eqondile lifana nobude obuqondile belensi eqondile (do = f),
c) ibanga lento ukusuka kulensi eqondile likhulu kunobude obuqondile belensi eqondile (do > f).
Kwaziwa:
Ubude be-focal (f) belensi eqondile = 20 cm
Ubude be-focal lens ye-convex bubonakala bulungile ngoba indawo egxile kulens ye-convex ingokoqobo, lapho ukukhanya kudlula khona endaweni egxile.
Ukuphakama kwento (h) = 10 cm
Isixazululo:
Ibanga lento lincane kunobude bokugxila belensi eqondile (do > f)
Ake sithi ibanga lento lingu-5 cm, 10 cm kanye no-15 cm.
a) Uma ibanga lento (do) = 5 cm
Ibanga lesithombe (di)
1/di = 1/f – 1/do = 1/20 – 1/5 = 1/20 – 4/20 = -3/20
di = -20/3 = -6.7 cm
Ibanga lesithombe liyi-negative, okusho ukuthi isithombe sibonakala nge-virtual, lapho ukukhanya kungadluli khona esithombeni.
Ibanga lesithombe lingu-6.7 cm, liphakeme kunebanga lento elingu-5 cm.
Ukukhulisa isithombe (M)
M = -di / yenza = -(-6.7) / 5 = 6.7 / 5 = 1.3
Ukukhulisa isithombe kudlula u-1 kusho ukuthi usayizi wesithombe mkhulu kunosayizi wento.
Ukuphakama kwesithombe (hi)
Isibalo sokukhulisa isithombe:
M = sawubona / ho
hi = M ho = (1.3)(10 cm) = 13 cm
Ukuphakama kwesithombe, okusayinwe ukuthi kulungile, kusho ukuthi isithombe siqonde phezulu.
b) Uma ibanga lento (do) = 10 cm
Ibanga lesithombe (di)
1/di = 1/f – 1/do = 1/20 – 1/10 = 1/20 – 2/20 = -1/20
di = -20/1 = -20 cm
Ibanga lesithombe liyi-negative okusho ukuthi isithombe sibonakala nge-virtual, lapho ukukhanya kungadluli khona esithombeni.
Ibanga lesithombe elingu-20 cm likhulu kunebanga lento elingu-10 cm.
Ukukhulisa isithombe (M)
M = -di / yenza = -(-20)/10 = 20/10 = 2
Ukukhulisa isithombe kudlula u-1 kusho ukuthi usayizi wesithombe mkhulu kunosayizi wento.
Ukuphakama kwesithombe (hi)
Isibalo sokukhulisa isithombe:
M = sawubona / ho
hi = M h = (2)(10 cm) = 20 cm
Ukuphakama kwesithombe kuhle okusho ukuthi isithombe siqondile.
c) Uma ibanga lento (do) = 15 cm
Ibanga lesithombe (di)
1/di = 1/f – 1/do = 1/20 – 1/15 = 3/60 – 4/60 = -1/60
di = -60/1 = -60 cm
Ibanga lesithombe liyi-negative okusho ukuthi isithombe sibonakala nge-virtual, lapho ukukhanya kungadluli khona esithombeni.
Ibanga lesithombe elingu-60 cm likhulu kunebanga lento elingu-15 cm.
Ukukhulisa isithombe (M)
M = -di / yenza = -(-60)/15 = 60/15 = 4
Ukukhulisa isithombe kudlula u-1 kusho ukuthi usayizi wesithombe mkhulu kunosayizi wento.
Ukuphakama kwesithombe (hi)
Isibalo sokukhulisa isithombe:
M = sawubona / h
hi = M h = (4)(10 cm) = 40 cm
Ukuphakama kwesithombe kuhle okusho ukuthi isithombe siqondile.
Ibanga lento lilingana nobude be-focal lens ye-convex (do = f)
Isithombe sisebangeni elingenamkhawulo.
Ibanga lento likhulu kunobude bokugxila belensi eqondile (do > f)
Ake sithi ibanga lento lingu-30 cm, 40 cm kanye no-50 cm.
a ) Uma ibanga lento (do) = 30 cm
Ibanga lesithombe (di)
1/di = 1/f – 1/do = 1/20 – 1/30 = 3/60 – 2/60 = 1/60
di = 60/1 = 60 cm
Ibanga lesithombe lihle, okusho ukuthi isithombe singokoqobo, lapho ukukhanya kudlula khona esithombeni.
Ibanga lesithombe elingu-60 cm likhulu kunebanga lento elingu-30 cm.
Ukukhulisa isithombe (M)
M = -di / do = -60/30 = -2
Ukwandiswa kwesithombe kudlula u-1, okusho ukuthi usayizi wesithombe mkhulu kunosayizi wento.
Ukuphakama kwesithombe (hi)
Isibalo sokukhulisa isithombe:
M = sawubona / h
hi = M h = (-2)(10 cm) = -20 cm
Ukuphakama kwesithombe kuyisibonakaliso esibi kusho ukuthi isithombe siphendukezelwe.
b) Uma ibanga lento (do) = 40 cm
Ibanga lesithombe (di)
1/di = 1/f – 1/do = 1/20 – 1/40 = 2/40 – 1/40 = 1/40
di = 40/1 = 40 cm
Ibanga lesithombe lihle, okusho ukuthi isithombe singokoqobo, lapho ukukhanya kudlula khona esithombeni.
Ibanga lesithombe lingu-40 cm, lilingana nebanga lento elingu-40 cm.
Ukukhulisa isithombe (M)
M = -di / do = -40/40 = -1
Ukukhulisa isithombe kungu-1 kusho ukuthi usayizi wesithombe ulingana nosayizi wento.
Ukuphakama kwesithombe (hi)
Isibalo sokukhulisa isithombe:
M = sawubona / ho
hi = M h = (-1)(10 cm) = -10 cm
Ukuphakama kwesithombe kuphansi okusho ukuthi isithombe siphendukezelwe.
b) Uma ibanga lento (do) = 50 cm
Ibanga lesithombe (di)
1/di = 1/f – 1/do = 1/20 – 1/50 = 5/100 – 2/100 = 3/100
di = 100/3 = 33.3 cm
Ibanga lesithombe lihle, okusho ukuthi isithombe singokoqobo, lapho ukukhanya kudlula khona esithombeni.
Ibanga lesithombe elingu-33.3 cm lincane kunebanga lento elingu-50 cm.
Ukukhulisa isithombe (M)
M = -di / do = -33.3/40 = -0.8
Ukukhulisa isithombe kuncane kuno-1, okusho ukuthi usayizi wesithombe mncane kunosayizi wento.
Ukuphakama kwesithombe (hi)
Isibalo sokukhulisa isithombe:
M = sawubona / h
hi = M h = (-0.8)(10 cm) = -8 cm
Ukuphakama kwesithombe kuphansi, okusho ukuthi isithombe siguquliwe.
