As a photographer, I have long understood the need for a good tripod and camera mount when operating in low light and thus a need for a German Equatorial Mount for my tripod. Recently, I have started thinking about pursuing my love of photography again. I love taking landscape photographs while camping. Astrophotography is a natural extension of this endeavor, and with today’s technology I can image all night while I am around the fire or asleep in my tent. When I started my family my photographic hobby took a back seat, and this is something I hope to rectify this year.
A German Equatorial Mount (GEM) is a tripod mount which is oriented and aligned towards the north star on the polar axis. A motor or gear system mechanically compensates the camera / telescope for the rotation of the Earth at one revolution per day. This allows for the longer exposures when taking night time photographs especially when utilizes longer focal length lenses.
My first venture in astrophotography was a nightmare. My cheap telescope and Canon DSLR Rebol where both mounted on two different tripods. It was virtually impossible to keep the moon in frame for more than 10 seconds due to the high magnification of the telescope and speed of the earths rotation. This setup did allow a few photographs and I learned a lot, mostly of what not to do.
The draw back of the GEM, is that I do not have one. It is very easy just go buy one, however they can cost quite a bit. There are different options, one of which is a “barn door” style tracker, which I am also going to build in the short term. This is a DYI home brew project build using hinges and may be the subject of another post. A “barn door” tracker would not be suitable for telescope photography. I watched a you tube video of an astrophotgrapher and he was reviewing I used GEM for it only costs $1500. This is a bit out of my budget.
The final piece to fall into place, is that my son is taking STEM classes in school now. I thought that there is not better project to start than a DYI German Equatorial Mount. In order to complete this little project he would need to learn to use a lathe. He would have to learn to wire and program a stepper motor drive system probably powered and controlled by an arduino. When complete, he would learn to use computers for image processing.
For me, I get to work on a project with my son, and teach him the importance of building stuff. My estimate is he would be exposed to:
- Mechanical Engineering
- Computer Programming
- Computer Imaging
I will consider this project a success if I am able to photograph and simply have my DYI German Equatorial Mount compensate for the earths rotation.