Tuesday, February 17, 2015

exposure lecture notes


Exposure Lecture Notes

Exposure principles
3 things that effect how the image is captured in the camera:



Shutter speed
-speed that it takes the photo at (in seconds. Example 1/25 second)
-You want to have a very fast shutter speed for sports photos.
-The longer the shutter stays open, the more light enters the camera. The shutter can be fast (1/4000 sec.) or slow (1 min).  Fast shutter speeds freeze action.
-Use the sports mode if you want people to be frozen in time. Sports mode also lets you shoot consecutive photos very quickly, so you’ll have a big selection of shots.
-Side views are better for showing motion.
-Straight-on views are good for showing faces.
-Each angle has its value.
-Practice the technique Panning. This involves standing in one position and following a moving subject as it passes. Your goal is to keep the subject(s) in your frame while you shoot.  Subject is in focus, background is blurry. Like Nascar photos
-Once you get good at his, you can experiment using the “p” mode, which allows you to choose a slow shutter speed.

Aperture
- The width of our opening for our lens. The higher the number, the smaller the aperture. There is a hole with blades that open, allowing light in. The smaller the number, the larger the opening.  Subject crisp, background out of focus. Smaller aperture number.  Portraits are often taken in a large aperture number, to focus on the subject. The smaller the aperture, the less light comes through the camera. Fast shutter speed, tiny aperture, you might need to change the iso.
- Low is 1.9, high is 22 for example.
-If you want a landscape photo of the Grand Canyon, and you want the whole thing to be in focus, you want the aperture to be smaller.
-If you want to  a portrait picture, you would want the aperture to be high.
-The camera has an IRIS to control the amount of light it lets in, just like the human eye. We call this the F/Stop or the aperture.
-Large aperture reduces the area of sharp focus. Parts of person are in focus, and background is blurry.
-The small aperture expands the area of sharp focus. All of the person is in focus, but the background is like 50/50 in focus.
-Portrait mode. Softer background (larger aperture)
-A photo with three or more people is a group shot.
-Don’t let shadows fall onto your subject.











-ISO speed
(Digital single lens reflex=dslr)
-The sensitivity towards light.
-The mirror has to move out of the way for it take a photo. On new cameras, they don’t use a mirror a lot of the time.
-Iso starts at ~100 and goes up to 528,000 on some camera. High iso allows us to take pictures with almost no light. Especially at night, low light conditions. The trade off is lots of noise/grain when you shoot with high ISO. Low settings in ISO have almost no noise/grain.





Camera modes:


Locate the mode wheel on your camera. Every company has a unique wheel.
M=manual mode. You dial in shutter speed, iso and aperture by yourself.
AV= aperture value. Refers to aperture priority. You decide what the aperture is, but the camera decides everything else (iso, shutter speed)
TV= time value. Gives priority to the shutter speed. You decide what the shutter speed is, but the camera decides everything else.
Symbol with person & star next to them= night portrait (aka party mode)
Person running=sports (aka action mode)
Woman’s head= portrait mode
-Explore variations of each location, taking care to choose angles that avoid distracting backgrounds.
-Not all backgrounds need to be simple. Editorial portraits use backgrounds to tell a story. Interesting portraits take a few minutes longer to compose than a snapshot. The results are always worth the effort.
-Use props and unusual angles to create dramatic results.
-While telephoto is generally accepted as being best for portraits, dramatic shots can be achieved by using wide angle setting for close ups.
-the wide angle setting is also good for exaggerating perspective.
-take shots of the same subject using wide angle and telephoto. You’ll soon learn how these lens setting an be used.


Lighting:
-There are two types of natural lighting:
Hard light-direct sunlight
Soft lighting-overcast, shade, north window
-Most subjects look bad in direct sunlight.
-direct afternoon sun: no catch light, deep wrinkles on face, subject is squinting, painfully forced smile, face lowered and amateur looking shot.
-open shade is the best all-around lighting for portraits and small groups.
-if you can’t avoid direct sunlight, turn your subject away from the sun to keep them from squinting. You can use the camera flash in direct sun, to help get rid of the shady areas of the person
-many cameras have a button to pop up the flash.
-window lighting is very good, as long as no direct sunlight is involved. North facing windows are best.

Group shots:
-b/c the portrait mode limits the sharp focus to a small area, its not recommended for group shots unless everyone is the same distance to the camera.
- When the groups get large, the difference in head size gets very noticeable.
-With an open shade location you’ll be free to arrange your group in various ways and never worry about the lighting.
-The extreme high angle group shot is a clever solution to the difficult problem of making sure that nobody’s face gets blocked.
-Wide angle shots taken from ground level can be interesting.

Night mode:
Some cameras allow you to extend the time exposure portion of your exposure to 8 or 9 seconds. Check your manual.

Posing your subjects:
The study of posing begins with understanding these elements: head, shoulders, eyes, and hands.
-Straight on shot is fine, but if you can play around with how the person is arranged, you can make them look slimmer, taller, etc.
-Shoulders at a 45 degree angle to the camera is a very flattering pose for all subjects. Notice how the direction of the eyes can make the subject connect with the viewer or seem aloof or mysterious.
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