Sunday, January 5, 2014

Notes on photography

These notes were taken by me at a photography class held at Keeble and Shuchat in Palo Alto, CA, in December 2002.  Film cameras were still pretty popular back then, but many of the concepts are still applicable even for digital cameras.

Camera Formats

The following formats are available
  • 110
  • 35 mm
  • 2 ¼ (2 and a quarter) 120 film
  • 4” x 5” view camera
  • 8” x 10” view camera
  • 16” x 20”
As cameras get larger, objects need to be more still.

Two types of 36 mm cameras:
  • Range finder (very silent)
  • SLR (single lens reflex)
4 kinds of SLR cameras
  • Manual
  • Aperture priority camera
  • Shutter priority camera
  • Programmable
The brain of a camera is the light meter.

Shutter and aperture

Shutter speed numbers begin with the letter t or b. Shutter speed can be 1, 2, 4, 8, 15, 30, 60, 125, 250, 500, 1000, 2000, 4000, 6000, 8000. Shutter speeds that are normally used are 60, 125, and 250.

The shutter speed determines the amount of time of the exposure. You cannot handhold a camera at a shutter speed slower than 1/60th of a second.

Most point & shoot cameras have a shutter speed of 125.

A 50 mm lens is a copy of the pupil of the human eye.
The aperture determines the amount of light. The fstops specifies the aperture. Most apertures end at 22 or 16. fstop numbers are like 2.8, 5.6, etc.

4 common aperture numbers:
  • 4 (silver dollar)
  • 5.6 (half dollar)
  • 8 (quarter dollar)
  • 11 (dime)
The lower the number, the wider the opening.

Depth of field

The camera sees only height and breadth, no depth. Shut one of your eyes to “see the lurch” (loss of depth).

With a shallow depth of field, the background tends to be blurred.

A depth of field of infinity is as far as the human eye can see.

99% of the time, you don’t need to focus the camera. The camera is focused from x to infinity, where x is the setting. You only have to worry about focusing when getting close.

Some cameras have a depth-of-field preview button.

The more you close an aperture down, the more the depth of field increases (like squinting your eyes).

Exposure compensation

Need to let more light in to get correct flesh tone for Caucasians (either 1 f-stop or increase the shutter speed).

Black needs to be under-exposed (let in less light).

White needs to be over-exposed (let in more light).

Gray does not need anything special.

All you need to worry about in photography is light.

5 generalizations about light
  • Bright light
  • Even light/soft light
  • Dark and overcast
  • Back light
  • Mixed light (e.g. bright shafts of light through the trees in Muir Woods)
Whenever you turn the camera on, it thinks the light is even. On a bright day, pictures will be over exposed.

In bright light, you need to under-expose the picture by 1 f-stop or 1 shutter speed. Your starting point is where the camera is when you turn it on.

When dark, you need to over-expose by 1 f-stop or 1 shutter speed.

On a backlit subject, always over-expose.

In a mixed light situation, under- or over-expose depending on what the light condition is in the most important part of the picture.

You have to over- and under-expose because you have a reflected meter (as opposed to an incident meter). No camera has an incident meter built into it. Every camera has a reflected light meter.

C-41 B&W


Slide film/print film

Slide film is used for color publishing. Separate negatives for B&W, yellow, cyan, and magenta.

ISO, DIN, ASA – how fast the film is to light.
  • Slow (25-100) takes a lot of light to expose the film
  • Medium (200-400)
  • Fast (500-1600)
  • B&W – 3000
As the ISO increases, the quality may not be as good. You don’t have to worry about 1/60th of a second limitation if you have fast-enough film.

3 film makers
  • Kodak
  • Fuji
  • Agfa (a German brand that makes Kirkland film sold by Costco)
All film is very good. Kodakcolor favors red/brown. Kodak ektacolor favors blue. Fuji favors green. Agfa favors brown/red.

Amateur camera – not heavy-duty, only for occasional use.

Professional camera – designed for heavy-duty use (100’s of films a day).

Two types of film
  • Regular use film
  • Professional use film is refrigerated as soon as it is made until ready for use. The negatives must be developed within 24 hours.
Freshness matters. Useful to think of the banana analogy – green, ripe, over the hill.

Types of photographers
  • Amateur
  • Professional
  • Film Art

Get a filter to protect the lens. UV-haze filter is useful if you’re doing both B&W and color. You also get a daylight filter or skylight filter.
Polarizer filter is only used under 2 conditions – bright light, and large areas of snow. Also responsible for creating the “perfect blue” pictures of e.g. tropical seas. Do not over- or under-expose with a polarizer because it cuts light down 2 ½ times.

Ceran wrap, fog filters, and diffusion filters enhance “softness”.

K2, yellow filter gets you a picture like your eye sees it.

Sepia filter – everything is golden (has a brownish-gold effect).

  • Wide angle
  • Telephoto and fixed focus
  • Zoom
Normal lens is 50 mm. The most common wide-angle lens is 28 mm.

50 mm sees at 56 degrees.

28 mm sees at 78 degrees.

Wide angle lens is useful for close events, e.g. group photos during family events (allows you to fit more in a frame).

55 mm lens is called a macro lens. Macro lens can record something life size and is used to photograph objects like beetles and stamps. It’s good for close-ups, but it goes up to infinity, so it’s good for almost everything. It has a narrower (46 degrees) field of vision.

Telephoto lenses range from 75 mm to 5000 mm. Used for portraits, wild life, etc. where you have to bring the picture to you. Has a smaller field of vision. Creates good portrait with blur in the background.

Zoom lenses: The focal length of the lens has to match the shutter speed of the camera in order to hand-hold it.

For example, at 28 mm, use 1/30th and at 50 mm, use 1/60th. Suppose you have a zoom lens from 28 mm to 250 mm. When it’s at 250 mm, the shutter speed should be adjusted to 250 as well.

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