Search results
Results From The WOW.Com Content Network
Plate scale is usually expressed in arcseconds per mm: , where f is in mm, [1] or expressed in arcseconds per pixel after further division through the pixel scale. Plate scale is not changed when telescopes zoom in or out because the same amount of sky will be in the pixel whether it is enlarged or shrunk.
Pixels per inch (or pixels per centimetre) describes the detail of an image file when the print size is known. For example, a 100×100 pixel image printed in a 2 inch square has a resolution of 50 pixels per inch. Used this way, the measurement is meaningful when printing an image.
As dp is a physical unit it has an absolute value which can be measured in traditional units, e.g. for Android devices 1 dp equals 1/160 of inch or 0.15875 mm. While traditional pixels only refer to the display of information, device-independent pixels may also be used to measure user input such as input on a touch screen device.
Pixels can be used as a unit of measure such as: 2400 pixels per inch, 640 pixels per line, or spaced 10 pixels apart. Pixel art The measures " dots per inch " (dpi) and " pixels per inch " (ppi) are sometimes used interchangeably, but have distinct meanings, especially for printer devices, where dpi is a measure of the printer's density of dot ...
The read noise is the total of all the electronic noises in the conversion chain for the pixels in the sensor array. To compare it with photon noise, it must be referred back to its equivalent in photoelectrons, which requires the division of the noise measured in volts by the conversion gain of the pixel.
An image that is 2048 pixels in width and 1536 pixels in height has a total of 2048×1536 = 3,145,728 pixels or 3.1 megapixels. One could refer to it as 2048 by 1536 or a 3.1-megapixel image. The image would be a very low quality image (72ppi) if printed at about 28.5 inches wide, but a very good quality (300ppi) image if printed at about 7 ...
Other factors include pixel noise, pixel cross-talk, substrate penetration, and fill factor. A common problem among non-technicians is the use of the number of pixels on the detector to describe the resolution. If all sensors were the same size, this would be acceptable. Since they are not, the use of the number of pixels can be misleading.
A pixel is a dot that represents the smallest graphical measurement on a screen. Twips are the default unit of measurement in Visual Basic (version 6 and earlier, prior to VB.NET). Converting between twips and screen pixels is achieved using the TwipsPerPixelX and TwipsPerPixelY properties [3] or the ScaleX and ScaleY methods. [4]