Observation in the natural sciences[1] is an act or instance of noticing or perceiving[2] and the acquisition of information from a primary source.
The scientific method requires observations of natural phenomena to formulate and test hypotheses.
Scientific instruments were developed to aid human abilities of observation, such as weighing scales, clocks, telescopes, microscopes, thermometers, cameras, and tape recorders, and also translate into perceptible form events that are unobservable by the senses, such as indicator dyes, voltmeters, spectrometers, infrared cameras, oscilloscopes, interferometers, Geiger counters, and radio receivers.
[6] Human perception occurs by a complex, unconscious process of abstraction, in which certain details of the incoming sense data are noticed and remembered, and the rest is forgotten.
What is kept and what is thrown away depends on an internal model or representation of the world, called by psychologists a schema, that is built up over our entire lives.
This has recently become an issue with digitally enhanced images published as experimental data in papers in scientific journals.
Some scientific journals have begun to set detailed standards for what types of image processing are allowed in research results.
Computerized instruments often keep a copy of the "raw data" from sensors before processing, which is the ultimate defense against processing bias, and similarly, scientific standards require preservation of the original unenhanced "raw" versions of images used as research data.