extraoral and intraoral photography

1. Supervision: Prof. Dr. Maher Abd El-Salam Fouda
Prepared by: Kholod El-Bady
Mohammed Abdel-Salam
“Faculty of dentistry-Mansoura university”

2. The basic Orthodontic Record-taking is comprised of three main
types of records:
1. Study models
properly-trimmed
dental stone-cast
moulds.
2. Radiographs
Panoramic view
Lateral Cephalometric view.
3. Clinical photographs

3. The emphasis has long been on taking the first two (study models and X-rays), while the
third (clinical photographs) was often seen as a luxury; an unnecessary waste of the
clinician’s time, by many orthodontists!
Times have certainly changed. Now, there is more and more emphasis on dental
photography for the following reasons:
• Treatment planning
• Patient education
• Marketing
• Exchange of information with dental technician
• Consultation among colleagues
• Research and publication
• Teaching purposes
• Medico-legal issues

4. The main problems are
Inaccessibility
of oral
structures
Framing the
image
Lighting
within the
mouth
Achieving
reproducible
conditions

5. Why Go DIGITAL?
 Ability to repeat/delete unsuitable images on the spot, no need to wait till film is developed.
 Digital camera setups are cost-effective; no more buying film, no more developing costs.
 No more worries about where to store all the slides and “physical” photographs.
 The ability to enhance, or “post-process” your images.

6. Basic terms
 Resolution
 Focal length
 Focusing
 Exposure triangle

7. Exposure triangle
• Exposure relates to whether the image is
too light (overexposed) or too dark
(underexposed).
• If a tooth is overexposed then you will
lose highlight details and the teeth will
look ‘washed-out’ or all white.

10. • Aperture is a measure of how open or closed the lens’ iris is, and represented by f-number.
• The f-number is the ratio of the system's focal length to the diameter of the entrance pupil
• A wider aperture (or lower f-number) means more light will be let in by the lens, simply
because the opening is larger, and vice versa.
Aperture

12. Depth of Field
It is the distance in front and behind a focused-on object (which lies in focal plane) that
appears to be in focus.
In general, approximately 50% of the depth of field is in front of the focal plane and 50%
behind the focal plane.
Depth of field is a
byproduct of
aperture, and
working distance.

13. Aperture effect on DOF
Working distance effect on DOF

14. OR Longer Working distance (and larger focal length)

16. In dental photography we must always use an ideal point of focus, to obtain the most depth of
field, and get the right things into focus 

17. Depth of field error
Motion blur or camera shake error

18. Exposure triangle

19. Shutter Speed
• Shutter speed is a measure of how long the shutter remains open and thus, how long the
sensor is exposed to light.
• Faster shutter speeds give the sensor less time to collect light and thus, result in a lower
exposure, and vice versa.
• It is measured in fractions of second,
(1/500s is faster than 1/200s).

20. • The reason we might want to use a faster shutter speed is to stop motion (photographing a
child can`t stay still long), or avoid camera shake effect (if not using a tripod), allowing
us to maintain sharpness.
Motion blur or camera shake error

21. • As a general rule, denominator of shutter speed under any circumstances must not be
less than your chosen focal length (technical tip, to overcome camera shake)- here the subject is
static but we have blurry image due to camera shake and extremely slow shutter speed.

22. • Regarding exposure, Aperture size and shutter speed are package deal.
• Faster shutter speed demands increasing aperture size (note the decreased depth of field) to achieve
the same light exposure.

23. Exposure triangle

24. ISO• ISO measures the sensitivity of the
image sensor to light.
• The lower the number the less
sensitive your camera is to light
and the finer the grain.
• In dental photography, we usually
don`t increase ISO number more
than 100-200.

28. What about flash types ??

29. The Point Flash frequently produce
distracting shadows, which may obstruct
important details. These are often
irreparable using image editing software,
and will detract from the final quality of
the image.

30. Sometime they can produce fairly good light distribution when used in special manner and
direction by rotating the camera so that light passes with little obstructive structures.

31. In contrast, the Ring Flash eliminates such shadows by allowing a more even and
thorough distribution of light during extra and intra-oral photographs

32. Similar options
LED lights Flash diffuser

33.  In fact, the images have good exposure and are free of shadows, but a careful examination
of the images shows that they are flat, there is no three-dimensionality.
 To overcome this, Twin flashes were manufactured, where the light does not come
directly on the subject, but laterally, creating small light shadows that make the subject
more three-dimensional, highlighting details that direct light flattens.

37. 2 in 1 option
Metz-15-MS-1 flash
 Innovative wireless flash which is similar to a ring flash, but with only two light sources ,
that can be set to be 0 / 10 /20 degree.

38. Digital photography and documentation techniques in Dentistry and Dental Technology
Autori: Carlo Alberto Piacquadio
https://www.zerodonto.com/en/2013/02/digital-photography-documentation-dentistry/
Style italiano-flash levels
proyectoshm.com

39. HowMany Photographs Do We Need?
 Different clinicians take different numbers of
clinical photographs, depending on with
whom who you are communicating and which
information you want to gain from these
photos.
 Generally, full orthodontic record file should
include a minimum of NINE photographs;
FOUR extra-oral, and FIVE intraoral
photographs.

40. • A stable position for the photographer is important, since the
camera is hand-held
• and not placed on a tripod.
• The right hand is held against the upper part of the body, with
the left hand supporting the front of the lens.
• The eye is not pressed directly against the eyecup, but
slightly in back of it.

41. Extraoral photos
Portrait and profile photography
It is recommended that a specific area be set aside for this purpose (Dental Studio).
Patient and camera positions can be marked on the floor in order to ensure reproducible results.

42. Portraits with different perspectives using lenses with different focal
lengths: 28mm (a), 55 mm (b), 105 mm (c) and 200mm (d). The
most natural appearance results from using a 105-mm lens.
Working distance - Focal length correlation

43. Background:
• The background must allow a full
assessment without distractive
objects and must be non-reflective.
• Many recommendation are about
blue or black (patient hair !!)
opaque backgrounds.
• You may choose to orient the camera
vertically to capture the patient’s
head without excessive background
showing (minimal cropping).

44. Lighting:
Ring flashes should not be used at
all, as they result in a completely
flat reproduction of the face, and
because of their low power and
resulting large apertures, they
achieve images with too shallow a
depth of field. (MASTERING DIGITAL DENTAL
PHOTOGRAPHY-WOLFGANG BENGEL)
However, we can still achieve fairly
good results by direct flash with
certain tricks and positions 

45. • Regardless of whether constant light sources (studio lights) or flashguns are used, the light
source should be bright enough to allow apertures of between f/8-11 (isolate patient head)
• In order not to light the portrait too harshly, the light source should be made larger, either
by using a diffuser (soft box) or indirect flash by using a styrofoam sheet or a reflector.
Intraoral !

47. • In general, it is sufficient to light the face with one light source. The side away from the
light can be filled in using a reflector.
• Some digital SLRs offer a wireless flash function. The main flash is triggered by an
infrared device positioned on the camera or by the camera flash itself.

49. What`s inside the soft-box ?
• The flash light reflected from the inner silver walls, passes through the internal partition to
the first scattering screen, and then through the front screen for diffusion of light. Due to
The fact that the pulse of light passes through two scattering screens, light becomes soft.
• Light scattering reduces the contrast of shadows and light spots.

50. Standard Extraoral Views
• To ensure reproducible images, the accurate positioning is achieved by using basic reference
points which are the tragion, orbitals.
• These have corresponding points on the skin. The upper part of the tragus corresponds to the
tragion and the orbital points are the width of the eyelid below an eye which is relaxed and
looking straight ahead.The main reference lines are the "Frankfurt horizontal" (tragion-
orbital) and the orbital plane.
• Eyeglasses should be removed to avoid reflections. If the hair covers the ear it should be
pulled back.

51. Frontal Rest View
• The clinician’s positioning is at the same eye level. Shorter patients can stand on a special
stand and Taller ones can have a seat.
• The orbital plane horizontal in relation to the mid-horizontal grid line.
• The mid-sagittal plane of the face should pass through the mid-vertical grid line.

52. • The patient should hold their teeth and jaw in a relaxed (Rest) position, with the lips in contact (if
possible), and should look directly at the camera lens and not resting head back on the wall.
• The upper edge of the photograph should be just above the top of the head and the lower frame line
around the larynx.
• Light should come diagonally from the front, leaving the patient's shadow out of view of the
camera.
• Focus on the patient's eyes.

53. Frontal Smile View
• Same frontal rest view guidelines.
• A patient who is smiling for a photograph tends not to elevate the lip as extensively as a
laughing patient.
• Pay attention to those who tilt their heads as a reflex during smiling 

54. • The frankfort plane is horizontal and parallel
to the horizontal grid line.
• The patient should look straight ahead in a
relaxed manner, keeping his or her jaw closed
in a typical manner and the lips also relaxed.
• When photographing children, a third person
can be helpful by asking the child to look at
him.
Lateral view

55. • The image should be framed so that the upper edge of the photograph is just above the part
in the hair and the lower around the throat.
• Showing the back of the head is not necessary, till the ear is enough.
• It is recommended that the head be turned slightly (3 to 5 degrees) toward the camera.

56. • Lighting for lateral views should always come from the point of the nose. This has the
advantage of clearly showing the mandibular margin and keeping the patient's shadow out
of the picture.
• Focus on the patient's eye.

57. Additional Smile views (profile and oblique)
The profile smile image allows one to see the angulations of the maxillary incisors and also
occlusal plane orientation, an important aesthetic factor that patients see clearly and
orthodontists tend to miss because the inclination noted on cephalometric radiographs may
not represent what one sees on direct examination.

58. Oblique rest facial views
• The sagittal plane of the patient and the optical axis of the
camera are positioned 45 degrees to each other.
• From the Profile photo position, the patient is asked to turn
their heads slightly to their right (about 3/4 of the way), while
keeping their body still in the “Profile Shot” position i.e.
Facing forward.
• This view can be useful for examination of :
midface deformities, the prominence of the gonial angle, and
the length and definition of the border of the mandible, focus
on lip fullness and vermilion display.
• For a patient with obvious facial asymmetry, oblique views of
both sides are recommended.

59. • Difficulties can arise in reproducing the head
position of the patient for this shot.
• It is recommended that the patient turn his or
her head away from the camera until the
contour of the eye farthest away from the
camera appears to touch the lateral visible
contour of the orbita .
• Another recommendation is to turn the head
away until the tip of the nose is aligned to the
cheek.

60. Additional AP view with spatula/AP view mouth open
• For documentation of an uneven bite/canting
of occlusal plane, facial views can be taken
with the same settings as described earlier. A
wooden spatula held by the teeth.
• Optionally, the same facial view is taken with
the mouth wide open. Irregularities of the
temporomandibular joints can be shown.

61. Additional Submental view (Worm's-eye View)
• The head is tilted back about 45 degrees. To obtain a
reproducible inclination of the head the base of the nasal alar
should be aligned at 90 degrees to the camera lens axis
• Such a view may be taken to document mandibular
asymmetry.

62. Intraoral photos
Accessories for intraoral photography
 Retractors
 Mirrors

63. • Round (Small-medium-large)>> frontal / occlusal shots
• V-shape (Narrow-wide)>> buccal shots
 The size depends not only on the size of the oral cavity, but also the tone of the lips.
Retractors

64. Frontal view

65. Buccal view

66. Occlusal view

67. Occlusal view

68. “ Contrastors ”

69. • Retractors made of wire are also in use, The
disadvantage here is that 1st the center of the lips is
not held and that the 2nd highly polished metal can
cause reflections which spoil the image and can
lead to incorrect exposures when using TTL flash,
because the flash sensor can be "fooled" by the
strong reflections.
• Making the surface more matte (blasted with
aluminum oxide) can reduce the amount of
reflections.

70. • Smaller one-piece orthodontic bonding retractors are generally NOT a good choice for
orthodontic purposes, especially for buccal and occlusal shots, as their retraction potential is
very limited, and it can often prove to be a “painful experience” for the patient.
• The direction of pull of the retractors is always sideways and slightly forward, away from
the gingival tissues, this maximizes the field of view and minimizes patient discomfort.
• Wetting the retractors just before insertion eases the process of positioning them properly
with minimum patient discomfort

71. Mirrors
• Front-silvered mirrors seem to offer the best image
quality and light distribution.
• Glass or rear-coated silvered mirrors produce ghost
image resulting in “Haziness” or a “Double- Image”, this
often makes the image appear to have camera shake

72. • Metal mirrors are less expensive, robust, easily sterilized in an autoclave, BUT scratched
easily and produce a slightly darker image compared to glass mirrors,
• Moreover, metal mirrors with the bend in the middle make your camera’s TTL setting is get
fooled by the reflection off the bend in the mirror and reduces exposure which produces a
very dark image. (try to change camera angle  )

73. • It is preferred to use “long-handled” mirrors as they allow
better control.

74. Different shapes

75. • The image should be framed so that only the mirror image of the teeth is captured, NO
visible fingers,, mirror edges or non reflected structures.
• Slightly warming the mirror in warm water prior to insertion helps prevent “Fogging” of
the mirrors.
• The patient is instructed to breathe in through the mouth and out through the nose.
• Air syringes or aspirators should also be used to remove disturbing saliva bubbles.

76. • The height of the chair should be adjusted so that the patient's head
is somewhat lower than the head of the photographer.
• The photographer's leg should be supported by the outside edge of
the patient's chair in order to find a secure, comfortable position

77. Frontal view
• The photo should be taken 90° to the facial mid-line
using the upper frenal attachment as a guide.
• The dental mid-lines are not as reliable for this purpose
as they can be shifted.
• The center of the image is the facial midline at teeth
level (centrals contact point if not malposed)
• The edges of the photograph are in the vestibulum oris.
• Do not focus on the front of the dentition. For correct
depth of field, the point of focus should be around the
canines.

79. • The dental chair is raised to elbow-level of the clinician.
• Use the larger set of retractors, to avoid the center of the upper and lower lip from showing
in the photograph.
• Patient’s lips pulled sideways and away from the teeth and gingivae, This opens the
buccal corridor and the cheeks no longer lie against the buccal surfaces of the molars.
• The occlusal plane is parallel to the horizontal borders of the frame and at the middle.

80. • The teeth should be together in maximum intercuspation, although a complimentary image
with the teeth slightly apart may help in recording the appearance of incisal edges and teeth
leveling.
• Air-dry the teeth to minimize the appearance of saliva and to better capture the gingival
appearance.
• Lighting is provided by ring flash, dual flash system, or point flash located in the 12:00
o'clock position.

81. Lateral views
• The patient is asked to turn their head slightly so that the side to be captured is facing the
clinician.
• For direct photo:
 The clinician holds the near retractor (v-shaped type) and stretches it to the extent that
the last present molar is visible if possible, while the assistant maintains hold of the far
retractor (round type), without undue stretching.
 The shot is taken 90° to the canine premolar area for best visualization of the buccal
segment relationship.
 A useful tip would be for the clinician to fully stretch the near retractor just before
taking the shot to minimize any discomfort for the patient, and achieve maximum
visibility

83. • For mirror photo:
 A single cheek retractor is held loosely for the contralateral side and a buccal mirror is
used to both retract the tissue and visualize the teeth on the side being photographed.
 A sufficiently wide lateral mirror is inserted on the side to be photographed until the
posterior border lies distally of the last tooth in the vestibule. It is turned to the outside
as far as the cheeks and lips will allow.

84.  Care should be taken that the edge of the mirror does not rest on the gingiva firmly since
this can be very painful.
 To prevent part of the final tooth near the end of the mirror being photographed directly
along with the mirror image, the mirror should be moved outward slightly.
 The mirror is turned so that the occlusal plane runs across the middle.

85.  The camera is positioned as perpendicular as possible to the mirror image .
 The center of the photograph and focus point are around the canine or first premolar. the
side edges of the photograph are the labial surface of central incisor of the targeted side,
and the last possibly viewed molar.
 Lighting is provided by a ring flash or dual flash or point flash is used, it is positioned on
the side of the mirror (9:00 and 3:00 o'clock), to avoid shadow of retracted lip.

86. The teeth should be together in maximum intercuspation,
although a complimentary image with the teeth slightly apart
may help in curve of spee evaluation.

87. Occlusal mandibular view
• The small size round retractors are inserted into a Reverse “V” shape (Position 4 & 8) to
retract the lower lip.
• The retractors which have been shortened on one side may be used to give more room for
mirror.
• The patient is be asked to “lift his chin up” slightly, raise the tongue to the palate, and
breathe through the nose.

88. • The palatal mirror is inserted with the broader end toward distal.
• The mirror rests on the gingiva of the last molars. It is turned upwards with the mouth wide
open until it touches the incisal edges of the upper incisors.
• The camera is positioned perpendicular to the mirror image of the occlusal plane of the
dental arch (45 degree to the mirror itself).

89. • The center of the image is at the intersection of the sagittal plane with the line crossing the
second premolars
• Focus is on the second premolar.
• Lighting is provided by ring flash, dual flash system, or point flash located in the 12:00
o'clock position.

92. • The small size round retractors are inserted into a Reverse
“V” shape (Position 2 & 10 ) to retract the lower lip.
• The retractors which have been shortened on one side
may be used to give room for mirror.
• The patient is instructed to lower their head slightly.
• Use the mid-palatal raphe as a guide to get the shot
leveled.
• If point flash is used, it is turned to the 6:00 o'clock
position or you shift to be behind the patient and flash in
12:00 position.
Occlusal maxillary view

95. Occlusal mirror images

96. Segmental Lateral
view of the front
teeth
• Amount of overbite
• Reproduction ratio is 1:1
Overjet view
(direct or indirect)

97. Reproducible conditions - Making a series of photographs
If the aim is to show a course of treatment, all photographs should be taken under the same
conditions including:
• Position of the image center and framing.
• Magnification ratio.
• Direction and distance of camera.
 It is recommended to note the key data
used in photographing groups of teeth
on the patient's card.

98. Helpful Tips
 Ensure that the teeth are clean of plaque, lipstick and any other debris and suction
excessive saliva.
 The direction of pull of the retractors is always sideways and slightly forward, away from
the gingival tissues. This maximizes the field of view and minimizes patient discomfort.
 Wetting the retractors just before insertion eases the process of positioning them properly
with minimum patient discomfort.
 When taking occlusal “Mirror” shots, slightly warming the mirror in warm water prior to
insertion helps prevent “Fogging” of the mirrors which would prevent a clear image

99.  In certain cases, profuse salivary flow and “frothing” can affect the quality of the image
being taken, thus a saliva ejector can be used to eliminate saliva prior to taking each
photograph.
 During occlusal “mirror” shots, instruct the patient “open your biggest big” just prior to
pressing the camera button. This helps in obtaining the maximum mouth opening at the
right moment, and minimizes the patient’s fatigue during the procedure.
 It is recommended that all photographic records be taken before impression taking, to
eliminate the possibility of impression material being stuck between the teeth or the face
during photographic record-taking.

100. Basic terms
 Resolution
 Focal length
 Focusing
 Exposure triangle

101. Focal Length
 The focal length of your lens essentially determines how ‘zoomed in’ your photos are; the
higher the number, the more zoomed your lens will be.
 It’s the distance between the point of convergence in your lens to the sensor or film in your
camera, measured in millimeters.

103. If the place the rays cross is close to the
imaging sensor. This would make an object
appear small in the photograph
If the place the rays cross is further away
from the imaging sensor. This would make
the object appear much bigger

104. The smaller the focal length,
the wider the field of view.
(wide angle lens)
The higher the number, the
more narrow or “zoomed in”
your angle of view will be.
(narrow angle lens)

105. Wide-angle lens
o Takes in more of the
scene than what is
perceived by the human
eye.
o Range from 14mm to
45mm.
Normal lens
o A focal length that
corresponds to the human
eye, 50mm, also known as
the NIFTY FIFTY.
o Where the focal length varies
from 45mm to 85mm.
Telephoto lens (narrow
angle lens)
o A longer focal-length lens
than normal.
o Allows one to get close up.
o Focal lengths are 85mm to
2000mm.

107.  Zoom lens:
Zoom refers to the lens being able to change the focal length.
Focal lengths are 16-35mm, 24-85mm, 70-200mm, 150-500mm.
 Prime lens:
This is a fixed focal length lens.
Available focal lengths are 8mm, 24mm, 35mm, 50mm, 85mm, 105mm, 200mm, 500mm.

108. Macro lens
Macro photography is the art of taking photos of things very close up, allowing you to see
details in the photo that your eyes would never be able to see.

109. Why macro lens ?
1) 1:1 Magnification ratio
2) Longer working distance
3) Better image quality and sharpness
4) Wider aperture (more light-narrow depth of field/isolation)

110. Why macro lens ?
1:1 Magnification ratio:
The magnification ratio tells you how the image projected on the camera’s sensor compares
with the subject’s actual size, so a lens with a 1:2 ratio can project an image on its sensor up
to half the size of the subject while a lens with a 5:1 ratio can project an image five times the
size of the subject.

111. Why macro lens ?
1:1 Magnification ratio:
• A magnification ratio of 1:1 means that when the camera is positioned at the closest
focusing distance, the image formed on the sensor will be the same size as the subject.
• For this reason, a 1:1 ratio is also called "life size" or "standard".
• A lens isn't considered to be "true macro" unless it can achieve at least 1:1 magnification.
• Here is an example from 22mm width camera sensor at different working distances.
https://www.dpreview.com/articles/6519974919/macro-photography-understanding-magnification

112. Why macro lens ?
Longer working distance:
• Macro camera lenses normally have a fixed
focal length (i.E. They are "prime" lenses).
• Macro lenses come in a wide variety of focal
lengths (50mm, 100mm, and 180mm).
• Your focal length determines your working
distance from the subject.
• The longer your focal length, the further you
will be from what you are trying to shoot.

113. Why macro lens ?
Longer working distance:
The 18-55mm lens (that often comes with a purchase of a camera body kit) should NOT BE USED.
While this lens is ok for hobby photography, it is not appropriate for dental photography.
The smallest image that can be captured using this lens is a full mouth set at 55 mm. The short
working distance results in barrel distortion for both the facial and the intra oral views, and
also your shadow may get in the way of the shot.

116. Better image quality and sharpness
• Macro lenses use a "floating" optical element which constantly adjusts the lens's internal
geometry to give pin-sharp focusing, better contrast, and consistently high picture quality.
• Some lenses also include a vibration reduction (VR) system. This can be particularly
useful when shooting at slow shutter speeds or without a tripod.
Why macro lens ?

117. Wider aperture:
• Macro lenses normally have much wider apertures than normal lenses, giving excellent low-
light performance.
• The flip-side to this is that depth of field is very narrow, particularly for lenses with a long
focal length. Such a property is beneficial regarding isolation purposes(texture, shade, …etc.)
Why macro lens ?

119. Quick-fix alternative
CLOSE-UP LENSES
A close-up lens (sometimes referred to as close-up filter or a macro filter) mounts
onto the front of your lens using the filter thread.
They act like a magnifying glass, simply enlarging the image before it
hits the sensor.

120. Basic terms
 Resolution
 Focal length
 Focusing
 Exposure triangle

121. Focusing
• The technical definition of ‘focus’ is “the point where light rays
originating from a point on the object converge”.
• Imagine, for example, that you are taking a photograph of this dot: • .
In order to be sharply in focus, the light rays from that dot need to hit
as few pixels on your digital sensor as possible.

122. Ideally, you want the point of convergence to be exactly on your imaging chip— when
that happens, your photo is in perfect focus.

123. Number of AF Points
• Having a lot of AF points is particularly useful if you like to take lots of action shots of
things that rarely sit still!
• But in dental field, you'll probably be happy with a bare minimum of AF points, as you
can easily adjust your subjects or your position.

124. What Is Manual AF Selection?
• Autofocus points are what the camera uses to focus on a subject. You'll probably first
notice them when you press the shutter halfway. Many cameras will emit a "beep," and
some of the AF points will light up (often in a red or green color) in the viewfinder or on
the display screen.
• Manual AF selection often means that you can just select a single AF point, which will
give you a precise area on which to focus.

125. Focusing is best carried out by setting the camera to manual focusing rather than
automatic focusing and then moving the camera backwards and forwards to bring the
object into focus.
The reason for this approach is to ensure
reproducibility of images taken on different
occasions. You may need to make minor
changes to the focusing to give an ideal
coverage for the standard view.

126. 1. Set Iso number to 100.
2. Set shutter speed according to focal length
and patient/operator stability
(not less than 1/80, 1/200 is common preference)
3. Determine point of focus (according to type of view).
4. Determine aperture according to: desired depth of field (f22 intraoral
shots, f8-11 extraoral shots).
5. Determine Flash output power according to aperture .
(e.g: 1/4 for f 29 – 1/32 for f 18)
6. Determine working distance and focal length according to: magnification,
light conditions, focusing distance.

127. Basic terms
 Resolution
 Focal length
 Focusing
 Exposure triangle

128. Resolution
• A camera’s resolution is calculated by the number of megapixels (millions of pixels)
its digital image sensor is capable of capturing.
• A pixel is the smallest element in an image. Pixels are grouped together to create the
illusion of an image.
• The more is the number of pixels, the more details can be captured, and the more
sharper the image.
• The number of megapixels a camera is capable of capturing can be used to roughly
determine the largest high-quality print that the camera is ultimately capable of
producing.
Illustration of how the same image might appear at different pixel resolutions

129. • An image’s resolution is determined by the image’s pixel count-information- (pixels rows
X pixel columns)..expressed in MP, or Pixels per inch-pixel density- (ppi) which is the
number of pixels in each inch of the image.
• A display’s resolution is expressed in pixels per inch (ppi).
• A printer’s maximum resolution is expressed in dots per inch (dpi)—the number of dots it
can place within a square inch of paper.
• Dots per inch (dpi) relates only to printers, and varies from printer to printer. Generally,
there are 2.5 to 3 dots of ink per pixel. For example, a 600-dpi printer only requires a 150-
to 300-ppi image for best quality printing.

130. Camera Resolution: What does it Affect?
 Print size
 Cropping option
 Display size

131. Print Size:
• The more resolution, the larger the potential print size.
• Printing from digital images is
accomplished by squeezing a certain
number of Pixels Per Inch (PPI). A high
quality print with good details usually
involves printing at around 300 PPI, so
the size of the potential print is calculated
by taking image width and height and
dividing them by the PPI number.

132. • For example, a 12.1 MP resolution image
from the Nikon D700 has image dimensions
of 4,256 x 2,832. If you wanted to create a
high quality print with lots of details at 300
PPI, the print size would be limited to
approximately 14.2″ x 9.4″ print (4,256 / 300
= 14.2 and 2,832 / 300 = 9.4). Larger prints
would be possible, but they would require
you to drop the PPI to a lower number

134. • The fact is that megapixels are NOT everything. Despite
point and shoot cameras now coming with up to 10
megapixels their quality level is not necessarily as good as
a DSLR with only 8 or so.
• The main reason for this is that the image sensor
used in point and shoot digital cameras is
generally much smaller than the image sensor
used in a DSLR (the difference is often as much
as 25 times). This means that the pixels on a
point and shoot camera have to be much smaller
and collect fewer photons, so needs more ISO
number>> Noisy image

135. Camera Resolution: What does it Affect?
 Print size
 Cropping and Resizing
 Display size

136. Cropping and Resizing:
• The higher the resolution, the more room there is to potentially crop and resize images.
• Photoshop allows more control on resolution.
https://helpx.adobe.com/photoshop/kb/advanced-cropping-resizing-resampling-photoshop.html

137. Camera Resolution: What does it Affect?
 Print size
 Cropping and Resizing
 Display size

138. Display size:
• Monitors, TVs, Projectors, Phones, and other devices have seen big increases in resolution
and the increased space on those devices naturally led to the need to show higher resolution
images with more details.
• Images are of a fixed pixel size when they appear on your monitor. Your screen resolution
determines how large the image appears onscreen.
• A 100 x 100-pixel image uses about one-sixth
of the screen at 640 x 480, but it takes up only
about one-tenth of the screen at 1024 x 768.
Therefore, the image looks smaller at 1024 x
768 pixels than at 640 x 480 pixels.
So, we may have to zoom in the image and hence
lose some of its dtails

139. But, If you will be taking pictures that are intended for on low resolution screen viewing
only, you can set your camera to a low resolution setting like 2 or 3 megapixels for saving
storage space purposes.
Taking your pictures at a higher quality setting like 14 megapixels will not make the image
look better on a 72 PPI computer screen.

140. How to control file size and resolution?
• The Large setting will give you the maximum flexibility
and potentially the highest quality, but the images take up
more space on your memory card (and computer) and will
take a little longer to save and download.
• RAW offers the best image quality, but it's less convenient
because the files require post-processing to use them. JPG
is far more convenient because of its wide compatibility,
but it doesn't offer the same quality benefits.

142. DSLR Camera
Digital Single-lens Reflex Camera
 DIGITAL imaging sensor (no more
traditional films)
 SINGLE LENS REFLEX DESIGN, the
viewfinder of a DSLR presents an image
that will not differ substantially from what
is captured by the camera's sensor.
(avoid parallax error of traditional types)

143. A simplified illustration of the parallax of an object against a distant background due to
a perspective shift. When viewed from "Viewpoint A", the object appears to be in front of the
blue square. When the viewpoint is changed to "Viewpoint B", the object appears to have
moved in front of the red square.

144. DSLRStrengths
• Image Quality.. Large sensor
• Adaptability.. Multiple lenses
• Speed.. Focusing and shutter
• Optical Viewfinder
• Manual Controls
• Wide depth of field
• Quality Optics of lenses
DSLRweekness
• Price
• Size and weight
• Maintenance.. Change lenses,clean sensor
• Noise
• Complexity

145. Point and Shoot Camera
The minimum and most important requirement is that the camera must satisfy the possibility
of using the aperture priority mode, which is normally indicated with the letter “A”,
and the flash must be as close and centralized as possible to the lens.