Image size and FOV

Image Size and Field of View

The size of the image on your computer screen and the field of view of the CCD are easily changed by simple techniques that do not require a more expensive camera to accomplish.

The relative size any CCD image appears on your computer monitor depends on the number of pixels represented in the image. But with most image presentation programs the size of the image may be enlarged or reduced by resampling the number of pixels in the image or by displaying the image at different zoom factors. For example, the following images are both from the same original ST-5C image file. The second image has simply been resampled to make it appear 50% larger on the computer screen.

Field of View

The field of view of the CCD may also be changed by changing the effective focal length of your optical system. This is usually accomplished with focal reducer lenses to increase the field of view or with barlow lenses to increase the magnification and reduce the field of view. The following images were taken with the same ST-5C camera and 8" SCT but with a focal reducer added to increase the field of view