Imaging Fundamentals · Overview

This section covers the basic physics behind astrophotography: optics (focal length, aperture, focal ratio, and sampling), exposure and gain, sensor types, and noise and signal-to-noise ratio. It is the starting point of the learning path, and the later sections on capture, calibration, and post-processing build on these concepts.

What this section covers

Optics Fundamentals Focal length, aperture, focal ratio, field of view and pixel scale, the diffraction limit, and telescope designs.

Exposure, Gain, and ISO Exposure constraints, the gain–ISO equivalence, read noise, dynamic range, and sky-limited exposure.

Sensors: CMOS / CCD / Mono / OSC CMOS versus CCD trade-offs, mono plus filter wheel versus color OSC, and key metrics like quantum efficiency.

Noise and Signal-to-Noise Ratio: Why We Stack Signal and the four classes of noise, how SNR grows as √N, and the decisive role of total integration time.