Starting with the equations for the image illuminance at the focus of the objective, the exposition and sensitivity of the photomaterial, the formula for the weakest reached magnitude and the formula for the limiting magnitude of a point like source are derived. The influence of the atmospheric conditions is separated from the influence of the objective and the film. For point like sources the reached magnitude can be increased much more than usually stated, especially by taking the camera out of the Earth's atmosphere.
Bulletin Astronomique de Belgrade
- Pub Date:
- March 1992