How to Attach Your Smartphone or Camera to TelescopeThere are various methods for smartphones, mobile phones, compact and DSLR to connect camera to telescope for astrophotography and imaging.
Astrophotography with a smartphone or small digital cameras is possible with the right adaptor, and most of them can also be used for spotting scopes, binoculars, and telescopes. There are various ways to connect your smartphone or camera to your telescope.
The first option is to hold your camera or mobile phone to the eyepiece. This works best for smaller sensor sizes, such as those found in smartphones, and for larger targets, such as the moon. You will need to set the shutter speed quite fast to eliminate movement, and you may get some vignetting around the edges depending on placement, eyepiece and lens size.
The best option for smartphones is a cheap adaptor which combines a clamp for the eyepiece and a universal mobile phone holder, which is commonly found in car phone brackets. These will allow you to accurately position the smartphone on the eyepiece and hold the phone steady.
Top Tip: When using a mobile phone camera, you can also use hands-free earphones as a shutter release! Press the volume buttons to take a picture. This eliminates needing to touch the screen and shake the phone while taking the photo.
For compact cameras and cameras with a fixed lens, a platform adaptor can be used. These combine a similar eyepiece clamp with a small platform upon which a light camera can be attached with the tripod screw. This allows you to position the lens and eyepiece accurately with thumb screws. You can also use some optical zoom to magnify the image further.
This platform adaptor can also be used with a smartphone by using a smartphone tripod grip, although you may not be able to get the mobile phone close enough to the eyepiece to eliminate vignetting.
For DSLR cameras there are several options available. A Canon EOS T-Mount adaptor is pictured, although they are available for almost any SLR to make. The T-Mount adaptor is a circular bracket attached to a digital camera body via the standard lens socket. The other end accepts the screw thread of the focuser or a Barlow lens. This lets you use your DSLR camera in "prime focus" mode. This results in almost perfect alignment with the optical pathway and securely holds the camera in the focuser, although it is advisable to wrap the camera strap around something just in case the camera slips out the focuser. The telescope lens effectively replaces the camera lens. The T-mount is a solely mechanical specification. Electrical or mechanical connections, such as for autofocus, are generally not provided.
Another option is an eyepiece projection kit. This allows the same alignment precision and allows you to use small eyepieces for greater magnification. The eyepiece sits inside the tube, which screws into the T-Mount adaptor for your camera and into the focuser.
These adaptors come in various shapes and sizes for 1.25" and 2" focusers. This method is also known as eyepiece projection.
The adaptor typically splits into two sections, the inner and outer tubes. When split in two, an eyepiece will fit inside the inner tube and be secured in place, then the outer tube slides over the top and is again secured with screws. One end of the adaptor fits into the focuser eyepiece slot, while the other attaches to the T-Mount and camera.
So far, I haven't had much success with my adaptor. I found it near impossible to focus as there isn't enough travel in the mechanism, or the fully extended focuser and fully extended adaptor and camera put a huge strain on the mount and focuser base. I also found that the image in the camera viewfinder is so faint that I can hardly see what I am trying to photograph.
When attaching a DSLR to a telescope in this way, bear in mind the weight of the camera and the distance from the focuser, as the forces can cause the focuser to become bent or damaged, especially with the eyepiece projection. You must ensure that your focuser can support the camera weight. I recommend wrapping the camera strap around something on the telescope, such as the finder scope. It won't come crashing to the ground if it should come loose from the adaptors.
