Why is the depth of field greater, and the image shar-,ako u to2q/ew:cs k83pieu*cm ;(z lper, when a camera lens is “stopped down” to a larger f-number? Ignore dict(kokuu * ozwpel -2e sm;8c,3qi/a:ffraction.

Describe how diffraction affects the statement o fl4/-ra33q) i sjkptlb3a6rthat the depth of field is greater and the qsa rb/ rll4pao3t)k-6 3ijf3 image sharper when a camera lens is “stopped down” to a larger f-number.

Why must a camera lens be moved farcxas nrs;-zpq/evnoq m /7u02(ev(8v ther from the film to focus on a closer objectn8eq o 2u/ npszv vev(0 /mr(;sqc7xa-?

Why are bifocals needed sshf:j3;tmv nmg7 : 84icl1zu mainly by older persons and not generally by younger peopl38hv;: 4 im17zmjtgunl :cssfe?

  Will a nearsighted person who wears corrective lenses :oupoej8u: l;in her glasses be able to see clearly underwater when wearing lu ;ouj p8:e:othose glasses?  ----待选择----yesno Use a diagram to show why or why not.

You can tell whether a person i va:drirwem-q01 v6 1i-kcya0 9jcxa:s nearsighted or farsighted by looking at the width of the face through their glasses. If the person’s face appears narrower through the glasses (Fig. Below), is the person farsighted or nearsiwa1j-aai vr -09xqiv0mc:ydk:r ce1 6ghted?

In attempting to discern distant details, people s,vv6y333ti4aa: moz q2 rcmz will sometimes squint. Why does t,tc qo3amy3v3z 2azrmi 4s:v 6his help?

Is the image formed on the retina ofi: aes iv3cy9, the human eye upright or inverted? Discuss the implications of this for our perception of c9 i,:y3vies aobjects.

The human eye is much like a camera — yet, when a camera shutter is left open ank9yw2y(lku; id the camera is moved, the image will be blurred; uw 9yk;i(l2 ykbut when you move your head with your eyes open, you still see clearly. Explain.

  Reading glasses use conver jns t10mphyab+ 7vu5*ging lenses. A simple magnifier is also a converging lens. Are reading glasses therefore magnisa7yt5jvh 1 b 0*upnm+fiers? ----待选择----yesno  Discuss the similarities and differences between converging lenses as used for these two different purposes.

Inexpensive microscopes for children’s use usually produmo q8 -oq,0b5;n3ivg:fpj tt pce images that are colorm8n ,gvqjp3io-p fbqt0 t ;:5oed at the edges. Why?

Spherical aberration in a thin lens is minimized if rays arva:i f:(fs ig5l ia-h-e bent equally by the two surfaces. If a planoconvex lens is used-::fhvsi i f-i(gaal5 to form a real image of an object at infinity, which surface should face the object? Use ray diagrams to show why.

Which aberrations presenm :cj xl(9;w- kuimcw jh)5lx5t in a simple lens are not present (or are greatly reduced) l5x juwxmc9kiw5):j -( lmh;c in the human eye?

Explain why chromatic aberrv a(:xyvf,x4 zation occurs for thin lenses but not for mirrors.

  By what factor can you improve resoletqm4afm0 az*ez *8 5iution, other things being equal, if you use blue lighfa*miz05 8 *a m4zeqett ($\lambda=450mm$) rather than red (700 $nm$)?  

Give at least two advantabz l;80qam0ka9.:p:ov thv gwges for the use of large reflecting mirrors in astronomical0v8 q mwtl0 oapk: h;ga:zb.9v telescopes.

Which color of visible light would give the best resolution in a microscopx.: u4vhkv(s-a(tsut e? Expvv4.(uh xa- skt( :sutlain.

  Atoms have diameters c/mn :9s-fxfd of about $10^{-8}\,$cm$. Can visible light be used to “see” an atom? ----待选择----yesno  Explain.

  A 55-mm-focal-length lens has f-stcdia(/jznw9*ok ; 462zwni 5x4 f eomsops ranging 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 t+ybk+ g:3rkx k6(os7 4 yzuoulens has a 14-$cm$ focal length and a lens diameter of 6.0 $cm$. What is its $f$-number? $f$/  

  A light meter reports75e+ye , uf:9p hjsdwf that a camera setting of $\frac{1}{250}\,s$ 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 photow) 0eq6fde -bbgraph is taken 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 can be adjusted sgvwz-bv3c3 (2h5:hqcvq rfi* o that it is 200.0 mm to 206.0 mm from the film. For what range of object distances c2-i vgzbf:c h qvr*cv3qw5(h3 an it be adjusted?    $\mathrm{m}\leq d_{\circ}\leq\infty$

  A nature photographer wishes to photogr aaewf1kh+ d xi+9;xn7aph a 28-mtall tree from a distance of 58 m. What focal-length lens should be used if the imag xa ;xdhn+a1 +wk9f7eie is to fill the 24-mm height of the film?    mm

A “pinhole” camera uses a t;e.bvtttn 8 p1-a9,0l dz ohmdiny pinhole instead of a lens. Show, using ray diagrams, how reasonably sharp imaght npt -e,d8a 09lvt1d;bmoz.es can be formed using such a pinhole camera. In particular, 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 exposure , 11gt5)vb 3xhxumbkj 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 2.ca( g21cfk. yk7j7i jj0 $cm$ 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 in Example 25–6 wore congvvp1r.zl + m-wv,x( wtact lenses corrected for the far poin1zv +mwr( -l,pxvw g.vt $(=\,\infty)$ 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 person whose near point isn ,nlk1cr6iv4; 5muee 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 op k/i9lkgs (+ef 14 $cm$. 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 holdin1mfpu7od2 er 65md+rp x-z p4kg a book at arm’s length, a distance 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 correctekr 6l6mk a.y:td by a $-3.50-diopter$ 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 are betg zgf q)qno;)x9+dd,s ween 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 ;9av /fq au+kaoi*on uqv)7t zup( x**than the 2.0 $cm$ of a normal eye?    cm

  One lens of a nearsighted person’s eyeglasses has a afqc-:ana:v4 l 6cw.go wwd+6focal 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 the eye–lens systw zii2 lwq3g y 2 xd7ak;:y1i4ya.rp3rem 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 x 2(a5b-ud *vysx/gelof 10.0 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 with a z kh7d t.3ovvw;)u6c wrelaxed eye if its focal length is o3w7vzd 6t.vhc;)kw u12 $cm$? =    $\times$

  What is the focal length of a magnifyinyv 6 9tpx7diw7 :bhk8sg glass of $3.5\times$ magnification for a relaxed normal eye?    cm

  A magnifier is rated a.- x4mdkvsv tto-*cgmh5 ,jj ,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 usingbeu3 kn 39jym/olc)z0 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 beetle is viewed wi 35:norfu*l akth 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 placei- kxr.z/9ubq*h b +:(x ioq;tb ;vtejd 5.55 $cm$ from a $+6.00-$cm$-focal-length$ lens. Calculate
(a) the position of the image,    cm
(b) the angular magnification. =    $\times$

  A magnifying glass withmu7 8ru4f* sg/fr-m lc a focal length of 8.5 $cm$ 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 rated at 2mzv 7l/mqyjvwe -8a 7$3.0\times$ 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 as.q7 obld-wezrcl 77 miu26 a6qwgzsl07t g-k8 tronomical telescope whose objective lens has a focal lelw20q7s6o cb q8 kit agz-.7w7 6del 7zlg-mrungth 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 an astronomical telescope is desired to beq 3w(ob4 x6-zzsjcpa9z.fak4 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 objective with capijz2w:sno+3n)1yb 0 7hmp focal length 85 $cm$ and a $+35-D$ eyepiece. What is the total magnification? =    $\times$

  An astronomical telescope has its two lenses sp7gbvuywczrb ,4u z oi 4/cx6u;kr(8 7paced 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 relaxed eye is y;ejweu) 8d + wl)ka6j 7u*gvv32.8 $cm$ long. If the objective lens has a focal length of 36.0 $cm$, what is the magnification? =    $\times$

  What is the magnifying power rq ;h adhpb)uju: 8e: yv1y1:jiol87mof an astronomical telescope using a reflecting mirror whose radius of :uqobm: ;)e7 jah18i 8 ydvh1lpuy:jrcurvature is 6.0 $m$ and an eyepiece whose focal length is 3.2 $cm$? =    $\times$

  The Moon’s image appears to be magnified dqrqr . 1z8/5vrbiz-w 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 rac/zlry og/ 0)lk1b;w ndius of curvature of 3.0 m for its objective mirror and a radius of curvaturon;k1/ )/yl zwrbcg l0e 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 with a focal length of gd z 9l:f.kq1 :fbl6vx1.40 $cm$. 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 agc y lr3s7m fb0r:, 1ouv hefnnr6.7q4ek-n;.0$times$ 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 1.8-,41vsw 7f wlwn$cm$-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 assumine 07;ssh)sql vg that the final image is located 25 $cm$ from the eyepiece (near point of a normal eye). $d_{oo}$ =    cm   $times$

  The eyepiece of a compound microsc:y. x8ipn /tlhope has a focal length of 2.70 $cm$, 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 maqgrq;iq / :k+bde of two very thin lenses, placed in contact, that have focal le/:+iqqqkg; brngths 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 particular sid ;:x9 pe rtva-0ww.fvtuation. A planoconvex lens of index of refraction 1.50 wf0r e.vvpa-wdt 9x :;and radius of curvature $R=12.0\mathrm{~$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) set by diffraction for)t4xlv:hu3j kdy+ c y3 the 100-in ylvdy x:)t +cj3uh34k. (254-$cm$ mirror diameter) Mt. Wilson telescope ($\lambda=550\mathrm{~nm}$)?   $ \times10^{ -5}\;^{\circ}$

  Suppose that you wish gnz2;xzv :*m0;14cpfxgwn s g to construct 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 camera has a focal fu;iad(ho6u r+m)w :u 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 away ax ozuak4 ga-d)fmq; 9bbl lo,f: zf(2,re 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 hu-x 55kn qem61go,jeg jr6mw-o /prig-man 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 ar;3v.ws)jf c 4lv o+ 2f)twmulme separated by about $400\times10^6\mathrm{~m.}$ 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 cx:ei5.m /dule8*ors)z12:rv2xn uv 0 rukne fall on a crystal whose atoms, lying in planes, are 1 *exzoc:)ruku0n is: rl 5. vr2xv8/mnu2deespaced 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 nm are directed at an unknown crystal. The seconf*as+f; cqxr7: ph hw4d diffraction maximum is recorded when t * hfw+r:xapfc4 hq;s7he 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 is observecw)c zh0z2hd -x7tpl4 i,8 pdld 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-ray mqw,yo c .v7dyelq7 j.z4 +xy(image that the X-ray beam consists of parallel rays. Whz+7cq7 xv wej4oqlydy ,.y.m(at would be the magnification 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 midday, and the sunlight got more intev ,4 7g8 kt)vokxc+jzvnse, a photographer noted thatj7 kv+)cv4 zxk gv8,to, if she 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 awayed:9wo/vt ohj;gg hg:tw c4j78c+ cc8 (assume infinity), the magnification of a camera lens is proportional ogw4;:chtg8h c8+7gcvjocejd9tw /: to its focal length.

  For a camera equipped with a 50-s u)fksg1d-.n:. mz.j efugnc2 f1ex,$mm$-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 objectstpao-2jqm ; f8a3o;)k iu7d9uy4 vgsi 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 po.id,t -pwj; kttr7t9xint of 15 $cm$. 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 pow+pflinm5de. h y2 *j+ser of a $+4.0-D$ lens used as a magnifier? Assume a relaxed normal eye. $M$ =    $\times$

  A physicist lost in the mountains tries to make a telescope using the lenses fjjxqy*9+(fy c/t *kyprom his reading glasses. Theyq tp /kc9y( fjxj*yy*+ have powers of $+2.0-D$ 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 use5yx o8g2ee iv1s $+2.5-diopter$ 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 altitude2m )a3mvicu+rcb l3h6rj-.il/du )ee s (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 distances, exposure times must bq73 kee a2 9nwyz,lyn,e increased because of thzqa,9 nkl y,2ewey 7n3e increased distance 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 eyepiece of a telesco:n y o h47wj5zo+qjbdv8 zu:(wpe are spaced 85 $cm$ apart. If the eyepiece is $+23$ diopters, what is the total magnification of the telescope? $M$ =    $\times$

  The Hubble Space Telescope, with an objective diameter o pal-olsl-p+wai 0tp 925(sndf 2.4 m, is viewing the Mo(slnl-lpp05to ip-d+aa w92 s on. Estimate the minimum 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 lense* vj* z1+dbqsis, one with $f=4.0\mathrm{~cm}$ 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 magnification xzj 5 tl2r)sl-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 numbedd(qt ;o58owm rs. Assuming it is necessary to resolve pwq o;td o58md(oints separated by 5 $cm$ 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. Below) has one flat surface and the xzritwv7g c*;:e kpu dm0s:7xp7 e)/ aother 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