5Objectives 1.Understand camera’s mechanisms & their functions 2.Able to control camera mechanisms for quality photo recording, and mastering in all features of your camera3.Understand techniques regarding to photo taking of the following… intra & extra-oral views, X-rays, and other dental objects
6Point A. Know few things about dental photography Point B. Mastering in dental photography
19Exposure Over-exposure How much do we know? How to prevent.. And how to do correction…Light metering…. What feature is appropriate
20ExposureStop… ( a technical term in photography), over one stop means…Correct exposure depends on the following factors…Internal factorsExternal factors
21Exposure Internal factors Film speed (ASA or ISO) Shutter speed… (exposure time 1/60 sec., 1/125 sec.)F-number (lens aperture, similar to eye iris, f-8, f-11, f-16 etc.)
22Exposure External factors Lighting environment Light metering systems : average metering, spot meteringContrast, background
23Electronic flashes Flash light control -- built-in, external flash Flash controlManualTTL (Through The Lens)Light intensity is controlled by camera CPU.
24Electronic flashes GN number (Flash Guide Number) GN = C × √ASA (C = distance in meter, ASA usually refer to 125 or 100) or…GN = C × f-number20 = 5 × f-number, thereby f-number = 4
25Depth of field Depends on the two factors F-number or lens aperture and…Film plane to object distanceDepth of field affects directly to intra-oral photography. Suggested apertures for intra-oral photograph are f-11, f-16 and f-22
26Depth of field Relation to f-number (lens aperture) Relation to film plane-object distanceFore-ground / back-ground effects
27How does this photo tell you regarding to depth of field?
28Depth of fieldRequired depth of field for macro photography (in dentistry) is f-11 or smaller apertures at cm. distance.Sample pictures of incorrect depth of field, f-5.6 and f-4
29Shutter speedFlash synchronization speed is usually at 1/60 sec. Higher speed 1/125 and 1/250 sec. assure still photograph.Example: Flash did not work. Photo was taken at low shutter speed, probably 1/8 second.
30Special purposes Pictures taken from microscope What is shutter release cable?When to use shutter release cable
36Film speed ASA or ISO: determination of light sensitivity 25, 64, 100, 200, 400, 800, 1600, 3200Suggested film speed for dental photos is 100, 200 for slide film, and 200 to 400 for digital camera
37Film speed ASA or ISO: determination of light sensitivity Color grain size ---- color film, slide filmNoise/signal ratio ---- digital cameraThe higher number ASA is set, the more light sensitivity is, and the poorer picture quality. It causes from larger grain size of silver halide, or noise of electronic signal.
38Films & Color saturation Professional film EPR (process E-6P) provides better color than other normal films, but requires constant cool storage place at 18 Celsius.
41Principles may apply to the CCD in digital camera
42Film processing Ektachrome slide films --- process E-6 Color negative films process C-41Kodakchrome slide film – use color staining technique, and has to be delivered to HK or Australia Kodak photo lab (similar to Agfa-chrome)
43Films, storage, duplication Film storageSlide picture storageHumidity, temperature, light exposureArchive film --- How long each slide film can be stored?Ektachrome= 50 yr.Kodakchrome= 100 yr.Slide duplication technique
46Filters – Color correction UV and skylight filterFluorescence filter (FL-W)Halogen light filter (light blue, e.g. Nikon B8)Select filter diameter that fit to your lensWhen should we use filter?WB mode (white balance) in VDO & digital camera for light color temperature correction
47Filters – Color correction Use B8 Nikon (light blue color filter) for tungsten, and halogen light; to correct light color temperatureSet WB (white balance) of a digital camera
48Filters – Color correction Taken with tungsten lighting mode : picture turned green from cool light temperature from fluorescence bulbs
49Taking photo of X-ray films Analog films, silver halideLight sourcesFluorescence filterFilm mounting, backlight interferingfairgoodpoor
50Digital camerasAll general mechanisms are similar to film loaded cameras.Instead of film, to be a media that receives light, it is CCD (charged couple device). CCD digitalized light from focused picture image. Then, transfer into digital information via CPU to digital memory unit.
51Selecting a cameraConsidering body , TTLLight metering systemPixel/CCD sizeLens quqlity
56Intra-oral photography What does it mean? …Magnification 1:1, 1:2, 1:4 when you check at your lens…Positioning – patient position, dentist positionNumber of frame (view) for complete intra-oral exam ---- are 11 frames.
57Intra-oral photography Intra-oral exam ---- are 11 frames1. front 10U/10L teeth2. front 6U/6L teeth3. buccal Rt U/L teeth occlude4. buccal Lt U/L teeth occlude5. palatal Rt U posterior
58Intra-oral photography Intra-oral exam ---- are 11 frames6. palatal Lt U posterior7. lingual Rt L posterior8. lingual Lt L posterior9. full plalatal occlusal10. full mandibular occlusal11. full lingual 6 anterior & lingual frenum
59Sample of required frames Be concentrate to frame the object (symmetrical setting)
60Intra-oral photography Require assistant for..1. hold reflector by hand2. blow reflector with air3. blow saliva with airRequire left and rightlower lingual views
61Extra-oral photography 1. patient --- front & side (profile) views2. models3. books (pictures, diagram etc.)4. X-ray filmConsider --- lighting, background, shutter release button, tripod, copy stand
62Extra-oral photography 5. slide duplication --- special equipment require?6. text slideDirect use of 5071Reverse text5072, Kodalith (black & white for print works)Ektachrome color slide --- C-41 processingThere is no problem, with Powerpoint Program,
63Extra-oral photography Models & other objectsText slidesX-raysPicture with macro lensHall’s articulatorGrinding feature of the upper mounting mechanismsPicture with normal lensReverse text slide
64Lighting technique for extra-oral photography Dark backgroundLight metering modes: average, center weight, spotLocation & number of light source, Slave flashSet black cloth as background
65Lighting technique for extra-oral photography Back lighting, side lighting, above lightingFlash control cord length?Color value & shadow
66Film processing C-41 for color print E-6 for color slide Push processing.. means…….
67Additional technique for film loaded camera Positioning slide picture in a slide trayRemove rolled film from film cassetteRewind and marking unexposed filmChecking camera if it is film loadedDouble lighting with slave flashDouble exposure
68Managing digital pictures Transfer digital information from memory unit, that incorporated in camera to a computer.Set file for each specific group of pictures.Save in hard disc, or in CD-R
69Presenting & Managing digital pictures Presentation of dental photoUse Microsoft PowerPoint software (.ppt)Insert text, picture, sound or movie to .ppt fileCompress picture digital information for Web/Screen = 96 dpi (dot per inch)Use custom animation feature
70Student Exercise Suggestion Student should record the following data of each exposure. These are..ASAF-numberDistance (direct or mirror image photo)Flash power lighting… these are future reference for each camera.
71SummarySelect camera/electronic flash system on required dental photo capability basisRead camera manual carefullyLearn new things, new technology relating to professional presentationPractice and improve your expertise
72General Specification to purchase a set for yourself Digital SLR camera50-55 mm macro lensElectronic ring flash with TTL featureGuide number flash min. at 8Practice manual focus. Set aperture priority mode. Suggesting aperture f-16 to get good depth of field. Able to get 1:1 magnification. Set ASA at 320
73Additional reading in dental photo. The Dental Clinic of North America …The New York State Dental JournalThe British Dental JournalThe Journal of Prosthetic DentistryOther local dental magazines and journals
74References180 Baht BahtSecond Edition Second Edition 2529
75ReferencesSample of a monthly photo magazine in Thai book market
76Suggest reading, demonstrate techniques via photos
77Suggest reading, demonstrate techniques via photos
78Selecting a digital camera A Reference Book175 BahtPrinted by Provision Co, Ltd
79Work to criticize …portraits… English photo magazines 1.Lighting 2.Framing3.Directing model person
80Where, when and how“Why”What is wrong with this picture?
81การใช้ ขาตั้ง ควบคุมการสั่นไหวของตัวกล้อง The use of tripod to decreasevibration.เทคนิค การถือกล้อง ประคองเลนส์Handling a camera
82What are the difference between these photos? How do you feel?ColorCompositionWhat are the difference between these photos?
84HeroA stone, however, large it may be, cannot be enough to build a tall castle. A man, however, great he may be, cannot be a hero by himself. A tall castle can be so tall because there are foundation stones that remain unknown. A man can be such a great hero because there are many heroes that remain unknown.Journalist and historian Tokutomi Soho ( )