Pixel no. Calculation
發表於 : 2010-02-03, 23:43This is an Excel file which can help u to calculate no. of pixel will be captured according to ur instrucments specifications. u need to know the focal length of the telescope, the pixel size of ur camera, the object size in degree.
Take moon as an example,
The apparent size of full moon is 32' 14.8" = 0.54 degree
Focal length of Equinox 80ED = 500mm
Pixel size of DMK41 = 4.65um
After u put all the data into the coresponding cells of the Excel file, u know at once the no. of pixel needed in DMK41 is about 1000. Since the resolution of DMK41 is 1280x960, the vertical direction may not big enough to show the full moon. On the other hand, the no. of pixel need in D80 is about 750 (in fact for APS sensor is 750x1.5 = 1125, or u can adjust the focal length by yourself). Since the resolution of D80 is 3872x2592, a small full moon will be captured in the file.
Enjoy!
Willis
Take moon as an example,
The apparent size of full moon is 32' 14.8" = 0.54 degree
Focal length of Equinox 80ED = 500mm
Pixel size of DMK41 = 4.65um
After u put all the data into the coresponding cells of the Excel file, u know at once the no. of pixel needed in DMK41 is about 1000. Since the resolution of DMK41 is 1280x960, the vertical direction may not big enough to show the full moon. On the other hand, the no. of pixel need in D80 is about 750 (in fact for APS sensor is 750x1.5 = 1125, or u can adjust the focal length by yourself). Since the resolution of D80 is 3872x2592, a small full moon will be captured in the file.
Enjoy!
Willis
