How to connect a digital SLR (DSLR) camera to telescope for digiscoping?

Digiscoping is becoming increasingly popular nowadays as people try to combine the function of powerful telescopes with advanced digital photographic technology. We have been frequently asked on how to connect a certain type of digital SLR cameras to a particular telescope model. This technical note is prepared to address some of the common aspects regarding digiscoping using DSLR cameras.

There are basically two methods to connect a DSLR camera to a telescope. The first method is to attach the SLR body without the camera lens directly to the scope using a DSLR camera adaptor. In this way the scope can effectively become a telephoto lens of the camera. Traditionally, this is achieved by using two separate components, a T-adaptor and a T-ring (also known as T2 mount). The T-ring is connected to the DSLR camera in place of the camera lens, and the camera is then connected to the scope’s eyepiece holder through the T-adaptor. There are different types of T-rings for different types of DSLR cameras, but the T-adaptor is designed to fit a range of T-rings. For those who are new to digiscoping, there can be confusions as to what type of T-rings should be purchased to fit a DSLR camera, and what T-adaptor can then fit the T-ring and the telescope.

More recently, a new type of
DSLR camera adaptors has become available, which combines the T-ring and T-adaptor into one component. Such an adaptor is available for those widely used camera brands such as Canon and Nikon. A major advantage of these new adaptors is that they can fit a wider range of products (eg. the Canon adaptor can fit almost all Canon SLR cameras with up to 135mm lens and almost all types of telescopes with a standard 1.25” eyepiece holder), and you only need one of them for digiscoping.

The second method of connecting a digital camera to scopes is to use a
universal camera adaptor. These adaptors enable you to attach a digital camera (including both SLR and non-SLR cameras) to a scope’s eyepiece. You do not need to remove the camera’s lens in this case, but the image quality is often not as good as using the first method.