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Cameras for Astrophotography

People have different hobbies. Some people love gardening, and others love to watch the stars and planets using their telescopes. Those involved in stargazing may at times take photographs of what they see through their telescopes. Usually, films are better for taking images of the stars, planets and everything else in between, as digital cameras still do not permit long exposures because the heat that is generated interferes with the camera components. On the other hand, films have the ability to absorb light for hours and can even work in low-light situations, like in astrophotography. This does not mean that digital cameras cannot be used in astrophotography. They can help to take photographs of bright objects in the sky, like the moon, various planets and bright start clusters. But digital single-lens reflex cameras for astrophotography are quite expensive.

People can choose from a range of cameras for astrophotography, including digital cameras.

Webcams for Astrophotography
- Webcams are not very expensive, and the learning curve to get good images is short. The best way to use webcams is through telescopes with high focal lengths. Rather than using the camera to take a single image, the webcam is used to take multiple frames like a video. Thereafter, using a special software, the bad frames are filtered out and just the good ones are used to make one single image. (See Reference 1) One of the most popular webcams used for astrophotography is Celestron NexImage. The webcam comes with a telescope adaptor as well as the software required to process the frames. Another popular webcam is the Meade LPI, which is primarily used to capture images of planets. This camera contains CMOS instead of CCD sensor, which is present in Celesteron NexImage. While CCD sensor gives sharper images, a CMOS sensor has an auto-guider to take images of planets in deep space.
High-End Planetary Cameras
- These cameras are ideal for taking photographs of different planets and the moon. This kind of camera has a high frame rate that does not compress data. Also it uses firewire to connect instead of the USB connection that is present in regular webcams. As there is no compression of data, the resultant images from these cameras are full of details. However, this kind of camera needs a computer that has a firewire port, and this can be a problem, as this port is not that common in computers. Resolve the problem with the help of a firewire expansion card if you are ready to shell out money to purchase this expensive camera.
Digital Single Lens Reflex (DSLR) Camera
- This kind of camera is perfect for taking images of the moon, sun, comets, star clusters, galaxies and nebulae. Usually, a digital SLR camera is a multipurpose camera that allows a person to take normal photographs and also photographs of heavenly objects. The length of the exposure is, however, limited. Even active cooling cannot help with long exposure imaging. This limitation is overcome by taking many short exposure images simultaneously. You can get DSLR cameras from Nikon as well as Canon.
CCD Camera
- This kind of camera is solely meant for astro-images and is perfect for taking photographs of star clusters, nebulae, comets and galaxies. The CCD camera is especially designed for telescopes and fits into the eye slot of the telescope. This camera has a built-in cooling system that makes long exposures possible. However, it is expensive to purchase and may not be within the reach of all people. The good news is that there are a few models that people can opt for. A CCD camera makes use of CCD sensor or chip and has a special kind of cooling mechanism, like thermoelectric cooling or Peltier cooling. Long exposures can cause the chip to heat up, leading to electronic noise in the last few images. This heating is tackled by way of the cooling mechanism, used during long exposures to ensure the quality of the images.

Photography