Camera

When it comes to cameras, we need a camera that allows to attach different lenses (aka interchangeable-lens cameras). Cameras with fixed lenses that cannot be replaced should be avoided. There are generally two options (1) general-purpose photographic cameras and (2) dedicated astrophotography cameras. Both can work depending on what objects you want to image.

General-purpose Photographic Cameras

The limitation of general purpose photographic cameras is that they include a filter (which is usually attached to the sensor) that does only allow for very little light within the H-alpha wavelength band (656 nm) pass through. Many deep-sky objects emit H-alpha which makes these objects appear red in the beautiful images that you can find on the internet. While not impossible, it will be very difficult to image such deep-sky objects using a stock general purpose camera. However, there are many deep-sky objects (e.g., galaxies) that emit little light at the H-alpha wavelength. Such objects can be imaged very well with unmodified general-purpose cameras. There is the option to remove the filter. Depending on the camera type, this can be very complicate. In addition, replacing the filter with an dedicated astrophotography filter can be costly. If the filter is removed and not replaced by a dedicated astrophotography filter, the camera cannot be used for day-light photography anymore.  My recommendation would be: If you already have a general-purpose photographic camera that allows to attach different lenses, give it a try. It may actually work quite well.

Dedicated Astrophotography Cameras

The advantage of these cameras is that they do not use the filter that blocks light at the H-alpha wavelength. However, these cameras may or may not have an UV/IR cut filter included. This is very important to know, because an UV/IR cut filter is needed to avoid bloated stars, when not using any other filters. If the camera does not include an UV/IR cut filter, such a filter need to be added. However, if using other filters, such as narrowband filters, an UV/IR cut filter is generally not needed. Things to consider when buying a dedicated astrophotography camera are (1) cooled vs. non-cooled cameras; (2) sensor size; and (3) pixel size. Cooled cameras have many advantages, including reduced noise and easier calibration frames (one set of dark frames can be used for multiple imaging sessions). However, they are more expensive ($1,000 and up) and require an extra power supply.  Non-cooled cameras are less costly ($150 and up) and do not require an extra power supply, but generate more noise and require to take calibration frames (including dark frames) for each session. The sensor size determines the field of view of your image. However, a small sensor with a wide-angle (short focal length) lens can produce the same field of view as a large sensor with a tele (long focal length) lens. However, not each combination of focal length (of the lens) and sensor size works optimally. In fact the pixel size determines if a lens with a given focal length is optimal for a given sensor. A good tool to find compatible lens/camera combinations is available at the astronomy tools website (look for CCD suitability).  Cameras with small camera sensors are generally less expensive than cameras with large sensors. If using a camera with a small camera sensor, it may be advantageous to select a camera with a small pixel size, such as the ZWO ASI 715MC or QHY-5III-715C that have a pixel size of only 1.45 um and currently cost $230 and $219, respectively. However, camera sensors with larger pixel generally have better light sensitivity. When using cameras with larger sensors, bigger pixel sizes can be advantageous. An example is the ZWO ASI482C that currently retails for $349 and has a pixel size of 5.8 um and a sensor size of 1/1.2" vs. a sensor size of 1/2.8" for the 715 cameras. The ASI482C works well with lenses of a focal length of more than 600mm and, therefore is a good choice when using telescopes in this focal range. The 715 cameras work well with lenses of a focal length in the range of 135mm to 400mm and, therefore is a good choice when using cheap vintage camera lenses. My recommendations, however, are the ZWO ASI585MC/MM when using telescopes and the ZWO ASI715MC or QHY-5III-715C when using vintage camera lenses. The ZWO ASI585MC/MM camera has a relatively large 1/1.2" sensor (just like the ASI482C) with a medium pixel size of 2.8 um. It currently retails at $399 or $499, depending on whether you select the color camera (MC, $399) or the monochrome camera (MM, $499). This camera can be used in a 2x2 binning mode which makes it the same as the ASI482C. However, the advantage of the ASI585 is that it is not affected by so-called amp-glow that plagues the ASI482C camera. The camera works well with lenses in the focal length range of 300mm to 1000mm.