Understanding Histograms:
A histogram gives the photographer the exposure and contrast information of the image. It can tell a photographer if the image has been overexposed or underexposed, and if the image is too flat or does not have much contrast. (See illustrations below.)
In digital photography, each pixel stands for a color, or has a specific color. Each of these colors is produced by a combination of red, green or blue, (RGB), which are the primary colors. Each pixel also has a brightness value. For a digital images with a bit depth of 8 bits, (which are all jpg. files), the brightness value is measured between 0-255, “255” being the lightest value or highlight, and “0” being the darkest value, or shadow area. Histograms illustrate the tonal range of the image by mapping it out, between 0-255, the image brightness values.
It is important to note that there is no specific histogram that an image should look like. A photographer may opt to shoot a scene with limited or extreme contrast range in order to convey a specific mood. The histogram, however, does provide very useful information especially when images are overexposed or underexposed.
Note on bit depth: Bit Depth quantifies how many unique colors are available in an image’s color palette. A jpeg file has an 8-bit color depth while RAW files have 12-16 bit color depth. As you get more advanced in your shooting and editing, you will prefer to shoot RAW files since these give you far more control over the exposure, tone and color quality of your image. RAW files are uncompressed and take up a lot more memory space in both your camera card and computer. When you decide to start using RAW files, you will need an external hard drive with at least 1T of memory space. Professional photographers will always prefer RAW files, but for this Intro class, the use of RAW files is not recommended.
camera and digital tutorials:
http://www.cambridgeincolour.com/tutorials
In digital photography, each pixel stands for a color, or has a specific color. Each of these colors is produced by a combination of red, green or blue, (RGB), which are the primary colors. Each pixel also has a brightness value. For a digital images with a bit depth of 8 bits, (which are all jpg. files), the brightness value is measured between 0-255, “255” being the lightest value or highlight, and “0” being the darkest value, or shadow area. Histograms illustrate the tonal range of the image by mapping it out, between 0-255, the image brightness values.
It is important to note that there is no specific histogram that an image should look like. A photographer may opt to shoot a scene with limited or extreme contrast range in order to convey a specific mood. The histogram, however, does provide very useful information especially when images are overexposed or underexposed.
Note on bit depth: Bit Depth quantifies how many unique colors are available in an image’s color palette. A jpeg file has an 8-bit color depth while RAW files have 12-16 bit color depth. As you get more advanced in your shooting and editing, you will prefer to shoot RAW files since these give you far more control over the exposure, tone and color quality of your image. RAW files are uncompressed and take up a lot more memory space in both your camera card and computer. When you decide to start using RAW files, you will need an external hard drive with at least 1T of memory space. Professional photographers will always prefer RAW files, but for this Intro class, the use of RAW files is not recommended.
camera and digital tutorials:
http://www.cambridgeincolour.com/tutorials
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