Learn about Photography
Learning for Digital Photography
10 imaging techniques to clear
Thursday, January 7, 2010
Pictures not clear Considered a step ladder basic problem is that no one has the cameraman must have to go through this checkpoint. Many times when viewing photos on the camera and LCD view screen is so clear some good. But enough to send photos to expand compressed or expanded to form a view on a computer screen at first, but think clearly better. Not intend to clear things. I believe several have come across this problem you need to do well.
White balance Optimization
Saturday, December 19, 2009
Functions allow users to customize various options. This article discusses the principles and use white balance to deliver accurate color images with valid out to be the best. Because we humans have the
ability to adjust the color perception by changing light conditions, such as white paper, if we look under the sun. We will see that the paper is white. We moved enough to look the same sheet of white paper umbrella at first we could see that the paper different colors. From the sun because the color of light has changed. But a few minutes later. Our eyes and brain. Adjust recognition to relationships in the visible light conditions as such. The result we see is a white paper plate. This phenomenon is called chromatic adpatation but because the digital camera is the CCD, which has been light (compared with Ertina the eye) can not modify the sensitivity to different colors look like when we picture white paper under daylight. assumed that the RGB values of a camera, R255, B255, G255 (if any pixel's RGB value is equivalent to a pixel is black, white, achromatic), but if we picture white paper plate with the same power to Tagsetn. Value R255 B180 G200 White paper shows that the image came to red other orange and white image into a white paper relies on software to help make up the RGB color from white light source that has different colors. each other equally valuable action will be called to adjust white balance by adjusting the white balance is not made only to pixels that are part of the white in the picture but do every pixel of the image.
Example of white balance.
Generally cameras do automatic white balance (Auto WB) to adjust the already however, will be the limit. Is correct only certain levels only. Observed from the three images below. Auto WB with a picture of Canon Powershot G1 camera image conditions under different light image is left. daylight (6500K) is the central image coolwhite (4800K) and the far right image is tungsten (illuminant A, 2856K).
ability to adjust the color perception by changing light conditions, such as white paper, if we look under the sun. We will see that the paper is white. We moved enough to look the same sheet of white paper umbrella at first we could see that the paper different colors. From the sun because the color of light has changed. But a few minutes later. Our eyes and brain. Adjust recognition to relationships in the visible light conditions as such. The result we see is a white paper plate. This phenomenon is called chromatic adpatation but because the digital camera is the CCD, which has been light (compared with Ertina the eye) can not modify the sensitivity to different colors look like when we picture white paper under daylight. assumed that the RGB values of a camera, R255, B255, G255 (if any pixel's RGB value is equivalent to a pixel is black, white, achromatic), but if we picture white paper plate with the same power to Tagsetn. Value R255 B180 G200 White paper shows that the image came to red other orange and white image into a white paper relies on software to help make up the RGB color from white light source that has different colors. each other equally valuable action will be called to adjust white balance by adjusting the white balance is not made only to pixels that are part of the white in the picture but do every pixel of the image.
Example of white balance.
Generally cameras do automatic white balance (Auto WB) to adjust the already however, will be the limit. Is correct only certain levels only. Observed from the three images below. Auto WB with a picture of Canon Powershot G1 camera image conditions under different light image is left. daylight (6500K) is the central image coolwhite (4800K) and the far right image is tungsten (illuminant A, 2856K).
Will see that the color chart image taken under daylight lighting and color coolwhite valid. But images under fire. Tagsetn to have distorted the red color somewhat. Gillette to clear up the work of the Auto WB, try to compare. Three images below the top three images. Photo below taken by the same camera, but set the camera WB is daylight.
We will see that the left image taken under daylight lighting to color correct. Images taken under lighting coolwhite be distorted to the red color slightly. And images taken under lighting Tagsetn is very distorted colors. And the more distorted picture taken with Auto WB This would indicate that the work of the Auto WB to help solve a color image to color more accurately. But the limitations commonly Auto WB will work well in a range of 4800-7500 K, if the light source color temperature or more. Less than this. Camera will not modify the color out. The camera quality, professional or semi-professional functions will allow users to manually adjust the WB (called the Custom WB) with the command to adjust the camera settings that the WB is white black. Its face is white, the most convenient. Because if the light source color distortion to the RGB values and white to the most different. Picture below shows. Comparison adjusting the custom WB set of images under white light and daylight coolwhite Tagsetn respectively.
From the image above to see images in the gray bar. Color accuracy of plus much more than an Auto WB adjustment with how the matter will see that. The orange and red. Image files from the Tulsa State also has not recreate that color well. The constraints between the object and the color of the light source color. And a part that can not be resolved. In addition to adjusting the white set custom WB, then the user may adjust the location of a gray or dark time. However, the discrepancy may be more white. Picture below shows. Comparison adjusting set custom WB on white (photo left), gray bar third from left (middle picture) and black (right image).
