Photography

							                    Photography

ACCT-AGD-6: Students will explore digital imaging
and multimedia.


                                  Written by Michael Simmons
                                          May 2010
        History of Photography
             Quick Review
 Camera Obscura
 Greek words:
  Camera – Room
  Obscura – Dark


 Room with a hole in the wall to draw pictures
  seen out side.

 Upside down image
       History of Photography

1827 - Joseph Niépce - metal plate
 covered with a chemical called bitumen
 (silver & chalk mixture) into a camera box

8 Hours to expose the photograph
      History of Photography
 1839 - Louis Daguerre -
  Daguerreotypes – metal
  plate with the silver
  iodized substance made
  a latent image when
  exposed to a mercury
  vapor. Once the latent
  image was fixed with a
  warm salt solution the
  image would become
  visible.
     History of Photography

1839 - William Talbot - Instead of making
 positives on metal plates, Talbot made
 negatives on paper.

Negative - area most exposed to the light
 was the darkest

Positives (picture) - the area most
 exposed to the light was the brightest
           Digital Camera
 Point and Shoot          SLR (dSLR) – Single
                            Lens Reflex




 Canon PowerShot SX1 IS
                                 Nikon DS 90 dSLR
    Advantages of Point and
            Shoot
Compact size
Lighter weight
Pre-set setting (f-stop, shutter, ect.)
Price
  Disadvantages of Point and
            Shoot
Picture quality
Little to no control over setting (f-stop,
 shutter)
Smaller aperture range
      Advantages of dSLR
You are in control of the camera
Better picture quality
Faster than Point & Shoot
Lenses are attachable so you can expand
 your focal point an zoom further.
When you look through the viewfinder, you
 actually look through mirrors and the lens
 just like with a 35 mm camera
 Disadvantages of Point and
           Shoot
SLRs will be heavier
SLRs will cost more
Most point and shoots are easy to use
No movie mode
You must know about f-stop and shutter
       What is a mega pixel?
Mega Pixel refers to the camera
 resolution.
Pixel is the smallest unit in a raster image
Mega Pixel is 1 million pixels
The higher the number of mega pixels less
 pixelization when the image is enlarged
 and printed. (10 mega pixel is better than
 5 mega pixel when images are to be
 printed)
  Recommended Resolutions

               Resolution needed for various print sizes
      Resolution              Avg. quality           Best quality
0.5 megapixels                  3x5 in.                    N/A
2 megapixels                   8x10 in.                 3x5 in.
4 megapixels                   11x14 in.                5x7 in.
6 megapixels                   16x20 in.               8x10 in.
8 megapixels                   20x30 in.              11x14 in.
10+ megapixels                 25x40 in.              13x17 in.

 http://cameras.about.com/od/photoprintingtips/a/resolution_tabl.htm
Basic Parts of the SLR Camera
                Aperture (f stop)– an
                 opening to let in a
                 controlled amount of
                 light

                Shutter - is a device
                 that allows light to pass
                 for a determined period
                 of time

                ISO – Film Speed –
                 Semiconductor
SLR and Aperture
      Aperture - this refers to the
       size of the opening letting light
       into the camera sensor. A
       larger shutter opening lets in
       more light, and a smaller
       shutter opening lets in less
       light.
Lens Opening (Aperture/F Stop)

1. The larger the opening, the greater
  amount of light that reaches the film.
2. The size of the lens opening is measured
  by f-stops.
(The larger the f-stop, the smaller the
  opening )
3. The f-stops are on next slide
                 Aperture




2.8   4.   5.6      8       11   16   22
SLR and Shutter Speed
         Shutter Speed - refers to the
          speed at which the shutter
          opens and closes. This is
          measured in fractions of
          seconds. A slower shutter
          speed lets in more light, and a
          faster shutter speed lets in
          less light.
     SLR and Shutter Speed
1. The time for which film is exposed to light is
   controlled by the shutter speed.

2. The faster the shutter speed, the shorter the
   duration of film exposure, and the less light reaches
   the film.

3. A dimly lit subject requires a slower shutter speed
   than a brightly lit subject.
     SLR and Shutter Speed
4. The following are shutter speed settings:
           Shutter Speed in fraction of second
        1          15          30        60      125
     most light

        250        500       1000
                           least light


5. Each setting represents a halving or doubling of light
   that reaches the film. For example, 1/8 allows light
   in for twice as much time as 1/15.
             SLR and ISO

ISO Setting (also referred to as 'Film
 Speed') - this represents the sensitivity
 of film to light. In a Digital SLR the ISO
 Settings stand for a change in the light
 sensitivity of the chip that takes the place
 of the film on the inside of the camera.
  Relationship between F-stop
       and Shutter Speed
1. The combination of these two controls
  determines how much light actually
  reaches the film.
2.Each designated f-stop or shutter speed
  doubles or halves the amount of light
  allowed in by the next designated f-stop or
  shutter speed.
  Relationship between F-stop
   and Shutter Speed Cont.
 F11 lets in half as much light as f8, and twice as
  much as f16
 A shutter speed of 1/60 lets in light for half as
  much time as1/30, and twice as much time as
  1/125
 Therefore, f-stop and shutter speed have a
  reciprocal relationship. If the shutter speed is
  slowed down ( to allow more light to reach the
  film), the f-stop must be closed down ( to let less
  light strike the film) to make an equivalent
  exposure.
                        References
 http://blog.colormailer.com/choose-between-slr-and-point-and-shoot-
  cameras/
 http://answers.yahoo.com/question/index?qid=20100419171913AAknZY7
 http://www.geometer.org/beginner/slr.html
 http://en.wikipedia.org/wiki/Pixel#Megapixel
 http://cameras.about.com/od/photoprintingtips/a/resolution_tabl.htm
 http://www.ez-digital-photos.com/digital-photography-tips-
  fstopsdemystified.html
 http://www.watertown.k12.ma.us/dept/fapa/pdf/photo_study_guide_part_1.p
  df