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Photography. What is a Digital Camera?. Fixed lens or point and shoot. Single Lens Reflex. Large Format. Inside a digital SLR camera. Aperture. Shutter. Sensor. Inside a fixed lens SLR camera. What are Megapixels?. What are Megapixels?.
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Fixed lens or point and shoot Single Lens Reflex Large Format
Inside a digital SLR camera Aperture Shutter Sensor
What are Megapixels? A digital camera's effective pixel count is its horizontal resolution multiplied by its vertical resolution. An image 2,048 pixels across and 1,536 high has just over 3.1 megapixels a 2,560 x 1,920 image is just over 4.9 megapixels. The Human eye can comprehend a maximum of about 220 pixels per inch in A photo without seeing the pixels. Anything less then that is risky. Computer monitors show pixel info at a maximum of 72 ppi. The standard For printed material is 300 ppi. Or at least 240.
Numbers are dots per inch of resolution. Colors are a subjective judgement of print quality: purple is highest, orange is lowest.
Data Types A Raw file is… • • not an image file per se (it will require special software to view, though this software is easy to get).• typically a proprietary format (with the exception of Adobe’s DNG format that isn’t widely used yet).• uncompressed (an 8 megapixel camera will produce a 8 MB Raw file), the complete (lossless) data from the camera’s sensor.• higher in dynamic range (ability to display highlights and shadows).• not suitable for printing directly from the camera or without post processing.• read only (all changes are saved in an XMP “sidecar” file or to a JPEG or other image format).• sometimes admissable in a court as evidence (as opposed to a changeable image format).• waiting to be processed by your computer. In comparison a JPEG is… • • a standard format readable by any image program on the market or available open source.• compressed (by looking for redundancy in the data like a ZIP file or stripping out what human can’t perceive like a MP3).• fairly small in file size (an 8 megapixel camera will produce JPEG between 1 and 3 MB’s in size).• lower in dynamic range.• immediately suitable for printing, sharing, or posting on the Web.• not in need of correction most of the time (75% in my experience).• able to be manipulated, though not without losing data each time an edit is made
White Balance White balance is what the camera does to detect the right colors of the setting. For example, you know how florescent lighting has a more blueish pure white color, outdoor lighting looks great, while indoor home tungsten lighting comes off more orangey? Digital cameras adjust the white balance to make up for the changes in the color of lighting.
Camera Image Sensor ISO • What ISO denotes is how sensitive the image sensor is to the amount of light present. The higher the ISO, the more sensitive the image sensor and therefore the possibility to take pictures in low-light situations.
200 ISO is recommended for sunny outdoors, 400 ISO for cloudy outdoors, and 800 ISO for indoors. But that’s for beginners. Stick with 100 ISO in all environments. Learn how to manipulate the shutter speed and aperture to get enough light in low light conditions. If you continuously practice with a low ISO then you’ll get used to it.
Fast shutter speed Slow shutter speed
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