For most of history the practical sensor has been the human eye.
Limited by Sensitivity
Physiological considerations and human subjectivity, placed serious limits on what could be discovered.
The advent of photography in the last century was a monumental step forward in astronomy
It has the ability to record “unseeable” objects with long exposure times
Despite improvements, its efficiency remains very low.
For every 100 photons that strike the film, at best only three or four react with the silver in the film’s emulsion
Charged Coupled Device (CCD)
With better than 20% efficiency, they quickly won over the astronomical community
There sensitivity extends into the infrared spectrum
Its response to light is a linear function of incident flux and exposure time.
There is no reciprocity failure as encountered in long duration astrophotographs
A CCD camera can provide a personal window to the universe or total frustration
Blooming vs. Anti-Blooming
The first questions you should ask yourself
What kind of imaging are you interested in doing
The selection of your camera depends strongly on whether you want a system tuned for planets or deep-sky objects. In most cases your telescope and mount will make this choice for you.
While a deep-sky system can certainly record planets, and a planetary system can image galaxies, the best results almost always come from systems customized for a particular task.
The DEEP-SKY Camera must be:
Some means of cooling the CCD
Multi-pinned-phase mode (MPP)
A large detector (number of pixels verses pixel size)
600 pixel-square array with 20 micron pixels
1024 pixel-square array with 10 micron pixels