There are several ways to acquire magnified views of planets: afocal imaging with digital or optical zoom, prime focus with Barlow lenses, and eyepiece projection with hi-power eyepiece.
Afocal Imaging with Digital or Optical Zoom Place a smart phone camera or a digital camera on top of an eyepiece. This configuration is called afocal imaging, in which a camera with its lens is mounted next to another image-forming optical system such as a telescope with an eyepiece or a pair of binoculars. You may need a smart phone to telescope adapter or a universal camera adapter especially if you plan to use the camera’s digital or optical zoom.
Prime Focus with Barlow Lenses Remove the webcam’s lens and then connect the webcam to a telescope. This configuration is called prime focus and works with web cameras, dash cameras, and other action cameras, using a webcam-to-telescope adapter. Barlow lenses may be needed to increase magnification and reveal more details. Use a UV-IR filter if the web camera’s sensor is not equipped with a built-in filter.
Eyepiece Projection Project an image of a planet onto a camera’s sensor, though eyepiece projection. In this configuration, an image is formed on the web camera’s sensor with the use of a high-power eyepiece. It uses an adapter called eyepiece projection adapter to hold the web camera and eyepiece together. The adapter also allows the separation between the web camera and the eyepiece to be adjusted, as it affects image magnification.
Other Considerations in Imaging Planets Planets, as viewed with a small telescope, are very small. Image at high magnifications (long focal lengths) within the limits of your telescope. Always double check the camera’s focus. Use a tracking mount whenever possible. Take two to three minute video recordings of the planet, making sure that the planet remains in the camera’s view for the whole duration of the recording. Process the recording using a software that registers and stack images such as IRIS.
I use a 1990 Kenko NES equatorial mount with my refracting telescope. This mount features an RA motor drive with relatively accurate tracking, a polar scope for easy alignment with Polaris, altitude-azimuth adjustment knobs useful in performing precise polar alignment such as the declination drift alignment method, coarse and fine adjustment knobs, setting circles, and adjustable aluminum tripod. My mount has been modified to use a DIY controller to connect it with a laptop via USB and perform automated guiding needed in long-exposure photography of deep-sky objects.
To view sample images taken with the 1990 Kenko NES mount, click here. To view posts on DIY projects and astronomical equipment, click here.
The Logitech 4000 webcam is capable of imaging planets and can be modified to take long exposure images to serve as a guide camera. The modification requires a serial port to externally control the camera’s exposure time using a guiding software such as GuideMaster and PHD Guiding.
The long- exposure modification allows the camera to detect faint guide stars, which is a useful feature for a guide camera. The diagram shown here was a modified version of M. Burri’s (2002) parallel port interface for a Logitech 3000 which I have adapted to work with the newer Logitech 4000 and a serial port.
To view posts on DIY projects and astronomical equipment, click here.
This photo was taken in December 2011, in Antipolo, Philippines, during a total lunar eclipse. The moon appears red during totality and as it dims (in contrast to a bright full moon), the faint stars surrounding the moon becomes visible!
For a complete list of astrophoto images, click here.
The 2011 Sky-Watcher Equinox 100 ED 4 in f/9 refractor serves as my main telescope both for visual observation and astrophotography. The telescope comes with aluminum-lined wooden carrying case. It is supplied with two eyepieces: 25 mm and 5 mm. Supplied also is a 90-degree 2-inch diagonal mirror and an 8 by 50 finder scope.
The Optical Tube Assembly (OTA) features a 4-in f/9 extra-low dispersion (ED) apochromatic (APO) lens design. It has a 2-inch dual-speed Crayford focuser with a thumbscrew underneath for locking the draw tube.
To view sample photos taken with the Sky-Watcher Equinox 100ED, click here. To view posts on DIY projects and astronomical equipment, click here.