Why is the depth of fiel+0/dbjrbag3 ezn rvnmm4 40.8jxd+ofwo(e 4w d greater, and the image sharper, when a camera lens is “stopped down” to a larger f-number? Ignore diff fmo ww/oeg +z4 j008ner4vdaxrjn43+.(d mbbraction.

Describe how diffraction affects the statement that the depth of fie2:(za trmkkw*2ck3e 0d: xc btld is greater and02*m:tckk:3 (xca etrz2 bk dw the image sharper when a camera lens is “stopped down” to a larger f-number.

Why must a camera le umi/-do300r5 0ta1uq, 1o rzpw wctlfns be moved farther from the film to focus on a closer object,0tfuuz 0-tir1c w/0 wq1o ldp o53ram?

Why are bifocals needed mainly by older persons and not generally by younger pe9 rm97.xjo kl9vxom wxjst4/xsp, 20bpo4pf 0op. ,sob2xf4 ps0k9 94vp9xm7/pl wj j tx0ormoxle?

  Will a nearsighted person who wears cors6sfr)s7ekn ua w)fy +z1hy/ +vc ;,zqrective lenses in her glasses be able to sz+ s k)vzec6n), sa/ 1yq7sw;yf+urfhee clearly underwater when wearing those glasses?  ----待选择----yesno Use a diagram to show why or why not.

You can tell whether 8();sbiy q c4.rlv-oimay nlz iar6;,a person is nearsighted or farsighted by looking at the width;6yl;8-yicl roiina.s z4mr,ab(vq ) of the face through their glasses. If the person’s face appears narrower through the glasses (Fig. Below), is the person farsighted or nearsighted?

In attempting to discern distant details, peoplda amfl1 hcri8 tg3;.7e will sometimes squint. Why does this h7ai81;3ar.c tdhlf mgelp?

Is the image formed on the retina of the human eye upright or i.qoc - yvx50kznverted? Discuss the imy o zqv-x.kc05plications of this for our perception of objects.

The human eye is much like a camera — yet, when ao) gg(bveohz:v7;x m1 camera shutter is left open and the cameraovv1ho( ; g7e bxz):gm is moved, the image will be blurred; but when you move your head with your eyes open, you still see clearly. Explain.

  Reading glasses use converging lensekcxk9 hn3,, gks. A simple magnifier is also a converging lens. Are readin,g 3c ,k9hxkkng glasses therefore magnifiers? ----待选择----yesno  Discuss the similarities and differences between converging lenses as used for these two different purposes.

Inexpensive microscopes for childre0ihqcq3b)7 ;f(jw 9qmh8ks ban’s use usually produce images that are colored at the edges. Wh7( 3w hqs8bi;9q)fb akmq0jchy?

Spherical aberration in a thin d1 r ppx1jm0z-4clv p-lens is minimized if rays are bent equally by the two surfaces. If a planoconvex lens is used to form a real image of an object at infinity, which surface should face the objj d zvp0lpcx4mr1-- 1pect? Use ray diagrams to show why.

Which aberrations present in a simple lensxb6 ur au: u--pwj0,tm are not present (or are greatly reduced)m-t-pwuubx 0:6 jra,u in the human eye?

Explain why chromatic aberration occurs for thin lens w*/bbah fxjtf15iq2ca *05nqn3fn1u es but not for mirrors.

  By what factor can you improve m9vc7k2 6nh lp)w)p cs+ck4tt4wwin:resolution, other things being equal, if you use blue light ( )phpwsn9w) v6w t i+4clmccktk:27n4$\lambda=450mm$) rather than red (700 $nm$)?  

Give at least two advantages for the use of large reflectij,8.p9r -um7;syzex4 9b3 irk tzmc; gg;ijuing mirrors in astronomical telescopes.gy;-9zt7rmb9iux,z i; i.er8j;ks gmu4pc3 j

Which color of visible light would give the best resolution in a microscope? E4nae y500cb. s 5(;jk j strmc5ss/bowxp s4;/ nsy5s55js0.j0trcbkbwc ma ( oelain.

  Atoms have diameters of about yafn)v9d- /aj $10^{-8}\,$cm$. Can visible light be used to “see” an atom? ----待选择----yesno  Explain.

  A 55-mm-focal-length lens has f-stops ran l sveo/qg)pdn6.a )(hging from $f/1.4$ to $f/22$. What is the corresponding range of lens diaphragm diameters?    $\mathrm{mm}\leq D\leq$    $\mathrm{mm}$

  A television camera lens has a 1i/*a* q5i orga4-$cm$ focal length and a lens diameter of 6.0 $cm$. What is its $f$-number? $f$/  

  A light meter reports that a camera setting yhg4cj v2) q(oof $\frac{1}{250}\,s$ at $f/5.6$ will give a correct exposure. But the photographer wishes to use $f/11$ to increase the depth of field. What should the shutter speed be?$t_2$ = 1/   s

  A properly exposed photograph is takenw qu+3kh3;g/6buisjhw. q *bt at $f/16$ and $\frac{1}{60}\,s$ What lens opening would be required if the shutter speed were $\frac{1}{1000}\,s$? $f$/  

  If an $f$ = 135-mm telephoto lens is designed to cover object distances from 1.2 m to $\infty $, over what distance must the lens move relative to the plane of the film?    mm

  A 200-mm-focal-length lens c1 eubst5zu q5(an be adjusted so that it is 200.0 mm to 206.0 mm from the fisutbz15(q 5u elm. For what range of object distances can it be adjusted?    $\mathrm{m}\leq d_{\circ}\leq\infty$

  A nature photographer wishes to phu kw;dzjxe)0t 6yd-t1otograph a 28-mtall tree from a distance of 58 m. What focal-length lens should be used if thej6) ytu -w;10zxeddkt image is to fill the 24-mm height of the film?    mm

A “pinhole” camera uses a tiny pinhole instead of a lens. Show, uf(aw s el)g6 g9fts1d4ye-4jb sing ray diagrams, how reasonably sharp images can be formed using such a pinhole camera. In particull)9d(4sgsyj4g bw61fe et af- ar, consider two point objects 2.0 $cm$ apart that are 1.0 m from a 1.0-mm-diameter pinhole. Show that on a piece of film 7.0 $cm$ behind the pinhole the two objects produce two separate circles that do not overlap.

  Suppose that a correct ei1rh8g- g wl;z d)cj/cxposure is $\frac{1}{250}\,s$ at $f/11$ Under the same conditions, what exposure time would be needed for a pinhole camera (Problem 8) if the pinhole diameter is 1.0 mm and the film is 7.0 $cm$ from the hole? $t_2$ = 1/   s

  A human eyeball is about l bpz 3o3d2f1d2.0 $cm$ long, and the pupil has a maximum diameter of about 8.0 mm. What is the “speed” of this lens? $ f-stop$ = f/  

  If the nearsighted person i2 b ihbxg8qathda3 n/-a5t*9hn Example 25–6 wore contact lenses corrected for the h 98b*t iqaht 5n-ad2xg3/ bhafar point $(=\,\infty)$ show that the near point would be 41 $cm$. (Would glasses be better in this case?) glasses would be  ----待选择----betterworse 

  Reading glasses of what power are needed for a h*dkbys* iom;dm5y7r-b-g)hy6b d 1y person whose near point is 115 $cm$, so that he can read a computer screen at 55 $cm$? Assume a lens–eye distance of 1.8 $cm$.+    D

  A person has a far point of 14xztp2n v0.x :a $cm$. What power glasses would correct this vision if the glasses were placed 2.0 $cm$ from the eye?    What power contact lenses, placed on the eye, would the person need?   

  A person struggles to read by holding a book at arm’s length, a d j3-ykrq2 p,uuqv8q7v istance of 45 $cm$ away (= near point). What power of reading glasses should be prescribed for him, assuming they will be placed 2.0 $cm$ from the eye and he wants to read at the normal near point of 25 $cm$? +    D

  A person’s left eye is corrected by a 25zk xrz5/8t3xqa mhx*3 pg io$-3.50-diopter$ lens, 2.0 $cm$ from the eye.
(a) Is this person’s left eye near- or farsighted?  ----待选择----nearsightedfarsighted 
(b) What is this eye’s far point without glasses?    cm

  A person’s right eye can see objects clearly only if they arekbug1y4ie8h v k5-2*u f6eoyj between 25 $cm$ and 75 $cm$ away.
(a) What power of contact lens is required so that objects far away are sharp? -    D
(b) What will be the near point with the lens in place?    cm

  About how much longer is the nearsighted eye in Example 25–6 than the 2. n0:f2,vhgp fc0 $cm$ of a normal eye?    cm

  One lens of a nearsighted person’sn,mkzwx2x5y,qlv8+ a.c0n( w p,xk at eyeglasses has a focal length of $-22.0 \, cm$ and the lens is 1.8 $cm$ from the eye. If the person switches to contact lenses that are placed directly on the eye, what should be the focal length of the corresponding contact lens?    cm

  What is the focal length of the1ekv2iwzy1ho 0bp)s5s ;mt 9u eye–lens system when viewing an object
(a) at infinity,    cm
(b) 33 $cm$ from the eye? Assume that the lens–retina distance is 2.0 $cm$.   cm

  A nearsighted person has near and far points of 1g.apa7) )cj v sbsfjlt-b4a+u, 4qpq40.0 and 20.0 $cm$, respectively. If she puts on contact lenses with power $P\,=\,-4.00D$, what are her new near and far points?
near point    cm
far point    cm

  What is the magnification of a lens used wi- pz*3lg ho*rx iqzsa /*7,ntpth a relaxed eye if its focal length is 12 s*z*r7gxo-phnltai*,z/3q p $cm$? =    $\times$

  What is the focal lez +i6avh 6xb83s* 2l,qbzttdyngth of a magnifying glass of $3.5\times$ magnification for a relaxed normal eye?    cm

  A magnifier is rated agf(*z7xzo7 eie eb:r4 t $2.5\times$for a normal eye focusing on an image at the near point.
(a) What is its focal length?    cm
(b) What is its focal length if the $2.5\times$ refers to a relaxed eye?    cm

  Sherlock Holmes is usinxv7hw/+dcn: 5rh85iu). /wxcmafd qig a 9.00-$cm$-focal-length lens as his magnifying glass. To obtain maximum magnification, where must the object be placed (assume a normal eye), and what will be the magnification?
$d_o$ =    cm from the lens
M =    $\times$

  A 3.30-mm-wide beetlen0v 5gzd7o:o9h: sfpg is viewed with a 9.50-$cm$-focal-length lens. A normal eye views the image at its near point. Calculate
(a) the angular magnification, =    $\times$
(b) the width of the image,    mm
(c) the object distance from the lens.    cm from the lens

  A small insect is placed 5.. 1iw(ro1eczcin: k pgds/2 )e55 $cm$ from a $+6.00-$cm$-focal-length$ lens. Calculate
(a) the position of the image,    cm
(b) the angular magnification. =    $\times$

  A magnifying glass with a focal length of 8. :0iu szou-y5bo,j4rz5 $cm$ is used to read print placed at a distance of 7.5 $cm$. Calculate
(a) the position of the image;    cm
(b) the angular magnification. =    $\times$

  A magnifying glass is rated05)+ha ,cma *kf g*htuvl)l mkwjk8d ( at $3.0\times$ for a normal eye that is relaxed. What would be the magnification of this lens for a relaxed eye whose near point is
(a) 55 $cm$, =    $\times$
(b) 16 $cm$? Explain the differences. =    $\times$

  What is the magnification of an astronomical telescope whose obje4,0,qvkv0im: ( ,qr t jjijkzhctive lens has qkhj r :,,i0 (,q4k0zjijmvtva focal length of 76 $cm$ and whose eyepiece has a focal length of 2.8 $cm$? What is the overall length of the telescope when adjusted for a relaxed eye?
M =    $\times$
L =    $\times$

  The overall magnification of gr dbeni1*7b /an astronomical telescope is desired to be 25$\times$. If an objective of 78$-cm$ focal length is used,
what must be the focal length of the eyepiece? $f_e$ =    cm
What is the overall length of the telescope when adjusted for use by the relaxed eye? L =    cm

  An 8.0$\times$ binocular has 2.8$-$cm$-focal-length$ eyepieces. What is the focal length of the objective lenses?    cm

  An astronomical telescope has an objecha (ks)n;k vgzmk)* bsn rx7y(5a :t-ztive with focal length 85 $cm$ and a $+35-D$ eyepiece. What is the total magnification? =    $\times$

  An astronomical telescope has its t:n8iskt,w ;l3) auigx)d*ybu wo lenses spaced 75.2 $cm$ apart. If the objective lens has a focal length of 74.5 $cm$, what is the magnification of this telescope? Assume a relaxed eye. =    $\times$

  A Galilean telescope adjusted for a rs do-srwvn8wato x7( z 6tm03)elaxed eye is 32.8 $cm$ long. If the objective lens has a focal length of 36.0 $cm$, what is the magnification? =    $\times$

  What is the magnifying poy2 hxxgp8aoe ;-bjo7( wer of an astronomical telescope using a reflecting mirror whose radius of curvature is 6.0 7 jxpey8h (2o a-;xgob$m$ and an eyepiece whose focal length is 3.2 $cm$? =    $\times$

  The Moon’s image appears to be magnifiedya/qt5 d/j3qw 120$\times$ by a reflecting astronomical telescope with an eyepiece having a focal length of 3.2 $cm$. What are the focal length and radius of curvature of the main (objective) mirror? M =    m r =    m

  A 170$\times$ astronomical telescope is adjusted for a relaxed eye when the two lenses are 1.25 m apart. What is the focal length of each lens?
$f_e$ =    mm
$f_o$ =    m

  A reflecting telescope (Fig. Below) has a 3*36vzwj8hv epn1bkm radius of curvature of 3.0 m for its objective mirror vj3 z 1*ewp 3h8k6nmbvand a radius of curvature of $-1.50m$ for its eyepiece mirror. If the distance between the two mirrors is 0.90 m, how far in front of the eyepiece should you place the photographic film to record the image of a star? $d_{2i}$ =    m

  A microscope uses an eyepiece 5 j9 2boo;vgf9h./dvehhtej*: z y0drwith a focal length of 1.40 $cm$. Using a normal eye with a final image at infinity, the tube length is 17.5 $cm$ and the focal length of the objective lens is 0.65 $cm$. What is the magnification of the microscope? =    $\times$

  A 620 $\times$ microscope uses a 0.40-$cm$-focal-length objective lens. If the tube length is 17.5 $cm$, what is the focal length of the eyepiece? Assume a normal eye and that the final image is at infinity. $f_e$ =    cm

  A 17-$cm$-long microscope has an eyepiece with a focal length of 2.5 $cm$ and an objective with a focal length of 0.28 $cm$. What is the approximate magnification?    $times$

  A microscope has a 12.zuoy/oa d3 :jxpqrx8znj,6 5i9 c55vi 8rwk5b0$times$ eyepiece and a 59.0$times$ objective lens 20.0 $cm$ apart. Calculate
(a) the total magnification,    $times$
(b) the focal length of each lens, $f_e$ =    cm $f_o$ =    cm
(c) where the object must be for a normal relaxed eye to see it in focus. $d_o$ =    cm

  A microscope has a 1.8ylw hdg :c+fxl6/w4cedp75 h.-$cm$-focal-length eyepiece and a 0.80-$cm$ objective lens. Assuming a relaxed normal eye, calculate
(a) the position of the object if the distance between the lenses is 16.0 $cm$, $d_{oo}$ =    cm
(b) the total magnification.    $times$

  Repeat Problem 61 assuming that the final image is located 25jlvi /)6 cj9id $cm$ from the eyepiece (near point of a normal eye). $d_{oo}$ =    cm   $times$

  The eyepiece of a compound microscope has a focal length of 2.70l av:k/j9cpn -bxq 01j $cm$, and the objective lens has $f=0.740\mathrm{~cm}$. If an object is placed 0.790 $cm$ from the objective lens, calculate
(a) the distance between the lenses when the microscope is adjusted for a relaxed eye, $l$ =    cm
(b) the total magnification.    $\times$

  An achromatic lens is made of two very thin len8yrihy.dk .f :ses, placed in contact, that have focal le8 fyhri ky:d..ngths of $f_1=-28\mathrm{~cm}$ and $f_2=+23\mathrm{~$cm$}.$
(a) Is the combination converging or diverging?  ----待选择----convergingdiverging 
(b) What is the net focal length?    m

  Let’s examine spherical aberration in a pv fed(f ww;4c(articular situation. A planoconvex lens of index of refraction 1.50 and radius of curvaturew(c( edvff4;w $R=12.0\mathrm{~$cm$}$ is shown in (Fig. Below). Consider an incoming ray parallel to the principal axis and a height h above it as shown. Determine the distance d, from the flat face of the lens, to where this ray crosses the principal axis if
(a) $h=1.0\mathrm{~$cm$},$ $d_1$ =    cm
(b) $h=6.0\mathrm{~$cm$},$ $d_2$ =    cm
(c) How far apart are these “focal points”? $\Delta d$ =    cm
(d) What is the radius of the “circle of least confusion” produced by the $h=6.0-\mathrm{~$cm$},$ ray at the “focal point” for $h=1.0\mathrm{~$cm$},$? r =    cm

  What is the angular resolution limit (degrees) sl1y7zvv-xoenr uym j/(mg ) 1,et by diffraction for the 100-in. (21ryy mn 1 vlxge7,moz/(v-uj)54-$cm$ mirror diameter) Mt. Wilson telescope ($\lambda=550\mathrm{~nm}$)?   $ \times10^{ -5}\;^{\circ}$

  Suppose that you wish to cq1zo +h5ycb+z onstruct a telescope that can resolve features 7.0 $km$ across on the Moon, 384,000 $km$ away. You have a 2.0-$m$-focal-length objective lens whose diameter is 11.0 $cm$.
What focal-length eyepiece is needed if your eye can resolve objects 0.10 $mm$ apart at a distance of 25 $cm$? $f_e$ =    cm
What is the resolution limit (radians) set by the size of the objective lens (that is, by diffraction)?
Use $\lambda=550\mathrm{~nm.}$ $\theta$   $ \times10^{ -6}\;rad$

  The normal lens on a 35-mm ca7bhh+ su1wp:koh +qe: .6ns9 qn)fkpemera has a focal length of 50.0 $mm$. Its aperture diameter varies from a maximum of 25 $mm$ $(f/2)$ to a minimum of 3.0 mm $(f/16)$. Determine the resolution limit set by diffraction for $f/2$ and $f/16$. Specify as the number of lines per millimeter resolved on the film. Take $\lambda=550\mathrm{~nm.}$
For $\frac{f}{2}$ we have $\frac{1}{RP_2}$ =    lines/mm
For $\frac{f}{16}$ we have $\frac{1}{RP_2}$ =    lines/mm

  Two stars 15 light-years awrowe: g; sf)r:x,8x abay are barely resolved by a 55-$cm$ (mirror diameter) telescope. How far apart are the stars? Assume $\lambda=550\mathrm{~nm.}$ and that the resolution is limited by diffraction.   $ \times10^{11 }\;m$

  (a) How far away can a humaqnl06jlnso0/, r pa y2t 558y+fdhvqxn eye distinguish two car headlights 2.0 $m$ apart? Consider only diffraction effects and assume an eye pupil diameter of 5.0 $mm$ and a wavelength of 550 $nm$.
L =    km
(b) What is the minimum angular separation an eye could resolve when viewing two stars, considering only diffraction effects? In reality, it is about of arc. Why is it not equal to your answer in (b)? $\theta$ =    $\times 10^{-3}$ $^{\circ}$

  The Earth and Moon are separated by about ;uk,re sq3(; ztqd26,npnp sw$400\times10^6\mathrm{~m.}$ When Mars is $8\times10^{10}\mathrm{~m}$ from Earth, could a person standing on Mars resolve the Earth and its Moon as two separate objects without a telescope? Assume a pupil diameter of 5 $mm$ and $\lambda=550\mathrm{~nm}.$  ----待选择----yesno 

  X-rays of wavelength 0.133 nm fall on a crystal tzed0dct8d96 whose atoms, lying in planes, aret cd 980d6tezd spaced 0.280 $nm$ apart. At what angle \phi (relative to the surface, Fig. Below) must the X-rays be directed if the first diffraction maximum is to be observed? $\phi $ =    $^{\circ}\,$

  X-rays of wavelength 0.0973 n)bo/xx8b 6zglz, qcq4v a0da05x o7j e:3 lzppm are directed at an unknown crystal. The second diffraction maximum is req7)aa go4xp3zol0z:pd,lx/ 80zq 5xebb cj 6vcorded when the X-rays are directed at an angle of $\mathrm{23.4°}$ relative to the crystal surface. What is the spacing between crystal planes? d =    nm

  First-order Bragg diffraction ij6 vmm w; 59vdro-g;vb.j 5pmcs observed at $\mathrm{25.2°}$ related to the crystal surface, with spacing between atoms of 0.24 $nm$.
(a) At what angle will second order be observed? $\phi_2 $=    $^{\circ}\,$
(b) What is the wavelength of the X-rays? $\lambda $ =    nm

  (a) Suppose for a conventional x 18e 7t*wytt6*zi ognX-ray image that the X-ray beam consists of parallel rays. What would be the magnifi1tozet7i*n x y8 *gtw6cation of the image? a the magnification is   
(b) Suppose, instead, the X-rays come from a point source (as in Fig. Below) that is 15 $cm$ in front of a human body 25 $cm$ thick, and the film is pressed against the person’s back. Determine and discuss the range of magnifications that results. $m_1$ =    the magnification is  

  Sam purchases $+3.50-diopter$ eyeglasses which correct his faulty vision to put his near point at 25 $cm$. (Assume he wears the lenses 2.0 $cm$ from his eyes.)
(a) Calculate the focal length of Sam’s glasses.    cm
(b) Calculate Sam’s near point without glasses. his near point is    cm
(c) Pam, who has normal eyes with near point at 25 $cm$, puts on Sam’s glasses. Calculate Pam’s near point with Sam’s glasses on.    cm from her eyes

  As early morning passed toward micg 2ius 1l2d9odday, and the sunlight got more intense, a photographer noted that, if she uoildc1sg9 22 kept her shutter speed constant, she had to change the $f$-number from $f/5.6$ to $f/22$. By what factor had the sunlight intensity increased during that time? $I_2$ =    $I_1$

Show that for objects very far away (xg62)vl lvyeo b)vt) . z9)wglassume infinity), the magnification of a camera lens is proportional to it)vl xl.wvv6ty)l)2eg)9g z obs focal length.

  For a camera equipped witw89l* vi4jaf 3 m,b*qcqmfk13xy s: osh a 50-$mm$-focal-length lens, what is the object distance if the image height equals the object height? How far is the object from the film?
$d_o$ =    mm
d =    mm

  A woman can see clearly with her right eye only when objects b-d pqk30vpt2jru-e5 are between 45 $cm$ and 155 $cm$ away. Prescription bifocals should have what powers so that she can see distant objects clearly (upper part) and be able to read a book 25 $cm$ away (lower part) with her right eye? Assume that the glasses will be 2.0 $cm$ from the eye.
$P_1$ =    D(upper part)
$P_2$ =    D(lower part)

  A child has a near point of 1t0mlv1 ul ik9n7ox0 8o5 $cm$. What is the maximum magnification the child can obtain using an 8.0-$cm$-focal-length magnifier? What magnification can a normal eye obtain with the same lens? Which person sees more detail?
$M_1$ =    $\times$
$M_2$ =    $\times$

  What is the magnifying po nr* *ng+ibv;l0 wzh3 g (ajqsfs6d0i5wer of a $+4.0-D$ lens used as a magnifier? Assume a relaxed normal eye. $M$ =    $\times$

  A physicist lost in the mou2u ei wvx2c530 wbi ac3:2 e:bg0kmcafntains tries to make a telescope using the lenses from his reading glasses. They have powers of52cbv wxmu02cigkc33abaiw2 0f: e:e $+2.0-D$ and $+4.0-D$, respectively.
(a) What maximum magnification telescope is possible? $M$ =    $\times$
(b) Which lens should be used as the eyepiece?    D

  A 50-year-old man usest7 ,usu aeqelk4gi0w3, fj(y+qr 76hq $+2.5-diopter$ lenses to read a newspaper 25 $cm$ away. Ten years later, he must hold the paper 35 $cm$ away to see clearly with the same lenses. What power lenses does he need now in order to hold the paper 25 $cm$ away? (Distances are measured from the lens.) $P_2$ = +    D

  Spy planes fly at extremely high althnf b2oeo022h2 xaf+ gitudes (25 $km$) to avoid interception. Their cameras are reportedly able to discern features as small as 5 $cm$. What must be the minimum aperture of the camera lens to afford this resolution? (Use $\lambda=550\mathrm{~nm}.$)D =    cm

When shooting pictures at very short y6jf-tx ojup*y- u/w3distances, exposure times must be increased because of the increased di uj-tjwy3*py6xu/f -ostance of the lens from the film for a focused image.
(a) Show that when the object is so close to the camera that the image height equals the object height, the exposure time must be four times longer (or 2 f-stops) than when the object is a long distance away (say, $$\infty), given the same illumination and f-stop.
(b) Show that if $d_o$ is at least four or five times the focal length f of the lens, the exposure time is increased by less than half an f-stop relative to the same object being a great distance away.

  The objective lens and the eyepiec:( fr5bpuuxv0k5 ,rle+sffi/e of a telescope are spaced 85 $cm$ apart. If the eyepiece is $+23$ diopters, what is the total magnification of the telescope? $M$ =    $\times$

  The Hubble Space Telq.,s6pvif0dm.yn uzqa*s*7 gescope, with an objective diameter of 2.4 m, is viewing the Moon. Estimate the minimum zy.i7.6u* ag, sfdp0qvsmnq* distance between two objects on the Moon that the Hubble can distinguish. Consider diffraction of light of wavelength 550 nm. Assume the Hubble is near the Earth.    m

  Two converging lenses, one 53ll,bofza b6with $f=4.0\mathrm{~cm}$ and the other with $f=44\mathrm{~cm}$ are made into a telescope.
(a) What are the length and magnification? Which lens should be the eyepiece?
The distance between the two lenses is   cm
M =    $\times $
f =    cm
(b) Assume these lenses are now combined to make a microscope; if the magnification needs to be $25\times,$ how long would the microscope be?    cm

  An astronomical telescope has a magnificatir:p hq71;ggh2:i gibh,vn3s ron of 8.0. If the two lenses are 28 $cm$ apart, determine the focal length of each lens.
The focal length of the eyepiece lens is    cm
The focal length of the objective lens is    cm

  You want to design a spy satellite to photograph license plate numbers. Assvxxor y23nsu 7u8-r q2uming it is necessary to resolve points separated by -y2osunx7 vq 8xrru235 $cm$ with 550-$nm$ light, and that the satellite orbits at a height of 130 $km$, what minimum lens aperture (diameter) is required? D =    m

  A Lucite planoconvex lens (Fig. Belo,qw3mcso6;p/1d qlw aw) has one flat surface and the other has $R=18.4\mathrm{~cm}.$ This lens is used to view an object, located 66.0 $cm$ away from the lens, which is a mixture of red and yellow. The index of refraction of the glass is 1.5106 for red light and 1.5226 for yellow light. What are the locations of the red and yellow images formed by the lens? $d_{i\,red}$ =    cm
$d_{i\,orange}$ =    cm