Photography Midterm
Moderate DOF
- A middle F-Stop can be used to achieve this. - The middle ground of your photo will be in focus while the foreground and background will be blurry. - F-Stop could range from F2-F8 (depending on your camera's F-Stop Scale).
Memory Card Capacity for Quantity of Pictures
More GB = More photo storage
Equivalent Exposure
- As one thing changes, the other(s) must change as well. ISO may not need to be adjusted. - Example: ISO is set at whatever. 200 in this case. You have correct exposure at f/11 and 30. But you want a faster shutter speed, say 125. Moving from 1/30 to 1/125 is 2 steps. Therefore you much also move your aperture by 2 stops in the other direction, from f/11 to f/5.6 in order to maintain the same or equivalent exposure. The reverse is also true. If you want to go from 1/125 to 1/30 you have to close the aperture by 2 stops. If you open the aperture by 1 stop, you need to increase shutter speed by 1 step (i.e., 1/60 to 1/125) and if you close the aperture by 1 stop you need to slow down your shutter by 1 step. If you change your ISO, the camera will adjust the other settings to compensate. The price of a higher ISO is more noise and possible loss of detail. Normally ISO does not need to be changed.
When to Choose Different ISO Values
- Bright lighting, like outdoors in the sunshine, will require a lower ISO setting and therefore gives a cleaner image with less noise. - Poor lighting, like in a forest under cloudy skies, would require a higher ISO and typically result in noisier images.
Functions of Apertures
- Either adds a dimension to a photograph by blurring the background, or brings everything in focus. Most of the time, everything in focus would be F22. - Controls amount of light in the photo. - Impacts the Depth of Field: A large f-number such as f/32, (which means a smaller aperture) will bring all foreground and background objects in focus. A small f-number such as f/1.4 will isolate the foreground from the background by making the foreground objects sharp and the background blurry. - The larger the aperture, the more exposed the photo will be.
ISO Scale
- ISO stands for International Standards Organization. - It is a standardized industry scale for measuring sensitivity to light. - This can be used in relation to how sensitive camera film is to light, but more commonly today, it pertains to the sensitivity of a digital image sensor.
Purpose of Shutter Speeds
- It is responsible for creating dramatic effects by either freezing action or blurring motion.
Setting for Long Exposures
- Long exposures use a slow shutter speed to create that trail of light. - By keeping the shutter open and the aperture at the correct setting, it captures anything bright that is moving in the dark. - Long exposures can also be done during the day with the right aperture setting. - Tripod is almost always needed.
Maximum DOF
- Referred to as Hyper Focal Distance: the point at which you focus your lens to get the biggest depth of field. - Best for landscape photos. - F-Stop approximately (F11).
Which Shutter Speeds Will Do What?
- Slow shutter speeds are also used to photograph lightnings or other objects at night or in dim environments with a tripod. (1/250 - 1/8). Landscape photographers intentionally use slow shutter speeds to create a sense of motion on rivers and waterfalls, while keeping everything else in focus. - Fast shutter speeds can help to freeze action completely. If the shutter speed is slow, it can create an effect called "motion blur", where moving objects appear blurred along the direction of the motion. (Can be 1/500th of a second or 1/1000th of a second). - Long shutter speeds are typically above 1 second, when you have to use a tripod to get acceptably sharp images (for low-light/night photography or to capture movement).
Adjusting for Volume of Light
- The ISO setting on your camera controls the sensor's sensitivity to light. It's a third exposure control, alongside shutter speed and lens aperture, and together these make up what's called the "exposure triangle". - Most often, you can adjust the shutter speed and aperture to control exposure. - In poor light you will need to increase the shutter speed to the point where camera shake or subject movement becomes a problem.
Aperture Scale
- The wider it gets, the more light it lets in. - The smaller the number, the more light it allows. - Measured by F-Stop Scale. - Wider: f/1, f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22, Narrower... f/32, f/45, f/64, f/90, f/128 - For each number, the aperture decreases to half its size, allowing 50% less light through the lens.
Minimum DOF
- To achieve: An aperture of about f/2 will result in one thing being in focus and the rest of the image will be blurred. - Helps for focusing on one part of your shot.
Factors Affecting Depth of Field
1. Aperture: - Open your aperture all the way to 1.2 and the background will be blurry. - For a shallow depth of field (at a wide open aperture, f/2.8), only a small plane of the image will be in focus. - With a wide depth of field (and a closed down aperture, f/22), almost the entire image is in focus. 2. Subject to Camera Distance: - The closer your camera is to your subject, the more shallow depth of field you will have in your image. - Pull your camera far away from your subject and more items will be in focus, even when using the same aperture. The distance of your subject from the background will affect how much blur you'll get in the background. 3. Lens Focal Length: -Focal length is expressed in mm and a higher number means a bigger zoom, while a lower number means the lens can be used for wider shots. - The longer the focal length is, the shallow the depth of field will get. - You can achieve a shallow depth of field (Long Focal Length) when shooting at 200mm. (Focusing on one subject, like a person). - You can achieve sharpness in the maximum amount of the image as possible when working with a super wide angle (For example: 17mm). This works best for getting total sharpness in photos like landscapes. 4. Camera Sensor Size: - The bigger the sensor (large), the shallower the depth of field will be overall. - A crop sensor camera will help achieve sharpness and deep depth of field. (Works well for landscapes).
Image Quality at Different ISO Settings
As you increase your ISO, you start to introduce "digital noise" to your image. A higher ISO will produce a rougher-looking image and a decrease in image quality. A lower ISO will produce a more bright and clear image.
Full Shutter Speed Scale
Camera Shutter: - It opens and closes to expose the sensor to the light coming in through your lens when you press the shutter button. - The length of time that this shutter is open is called the shutter speed and also sometimes referred to as 'exposure time'. - Shutter speed is one of the three sides of our exposure triangle, along with aperture and ISO, that allow us to control the brightness of our image. - FULL SS SCALE: The scale increases/decreases by half. Shorter shutter speed. 1/8000 1/4000 1/2000 1/1000 1/500 1/250 1/125 1/60 1/30 1/15 1/8 1/4 1/2 1 2 4 8 15 30 Longer shutter speed.
Camera Presets for DOF and Motion Capture Control
DOF: - Depth of field is controlled by changing the aperture setting on your camera. - The larger the aperture, the shallower your depth of field will be, meaning a smaller portion of your image will be in focus. - The smaller the aperture, the deeper your depth of field will be, resulting in more of your image being in focus. Motion Capture Control: - If your shutter speed is fast (ex: 1/4000th of a second) it's not going to see much movement (unless the the subject is moving mighty fast). - If you select a longer shutter speed (ex: 5 seconds) you don't need your subject to move very much at all before you start to see blur.
Alternate Choices for DOF and Motion Capture with ISO settings
DOF: To maximize the depth of field for macro work, you need a small aperture. This can often be achieved on all-auto cameras by choosing the a high ISO--say, ISO 400 instead of ISO 100. Motion Capture: A higher ISO will help stop motion.
ISO Scale in Full Stop Increment
Full Stops: 100 200 400 800 1600 3200 6400 12500
File Choices for Picture Quality and Quantity
JPEG: - JPEG is the default format used by almost every digital camera ever made. Named after its developer, the Joint Photographic Experts Group (and pronounced "jay-peg") this format lets you specify both image size and compression. The smallest size is best for the Web and e-mail (although it will usually have to be reduced) and the largest for prints. - The JPEG format compresses images to make their files smaller, but many cameras let you specify how much they are compressed. This is a useful feature because there is a trade-off between compression and image quality. Less compression gives you better images so you can make larger prints, but you can't store as many images. Because you can squeeze more smaller or more compressed images onto a storage device, there may be times when you'll want to switch to the smaller size and sacrifice quality for quantity. RAW: - RAW images are often better than JPEG images because they are not processed in the camera, but on your more powerful desktop computer. These RAW files contain every bit of the captured data, unlike JPEGs which are always processed in the camera with some data being discarded. RAW files can be viewed, edited, and converted to other formats using most photo-editing software or programs included on a CD that comes with the camera. - When you select an image format, size, and compression, you're not only affecting image quality but also how many images can be stored on your memory card. Sometimes when there is no storage space left, you can switch to a smaller size and higher compression to squeeze a few more images onto the card.
Depth of Field
The distance at which the subject will stay in focus in front of and behind the main point of focus.
Purpose of WB
WB: The process of removing unrealistic color casts, so that objects which appear white in person are rendered white in your photo. Proper camera white balance has to take into account the "color temperature" of a light source, which refers to the relative warmth or coolness of white light.
