Camera Control
Automatic control
The ultimate dream of many eclipse chaser/Photographers is to have a reliable system control the camera while sitting back and enjoying the eclipse view. Many modern cameras support repeated exposures, bursts, and other features that are quite useful when photographing an eclipse. So how can one take advantage of such tools?
Click-Click-Click
Does your camera support burst mode? If so, then you can make use of it. Burst mode takes more than one picture, at different f/stops or exposures, to bracket an image. This is exactly what one should do during a total solar eclipse. A longer exposure brings in more corona while a shorter one reveals prominences. Cameras I've worked with allow for 1 or 2 f/stops worth of exposure changes.
An Intervalometer can be used to automate the clicks further. An intervalometer is a device that can be programmed to repeat clicking at regular intervals. That relieves the operator of having to keep pushing the exposure button. If you are happy with the range of the burst and have an intervalometer then you are there! Set the intervalometer to run exposures every couple of seconds for the duration of totality (add about 10 seconds at the start and end) and you will have a nice set of images when it is all done (assuming the camera remained pointed at the eclipse, was in focus, and the exposures reveal the details you are after).
An example is the Canon TC80N3 controller which features a variety of timing options - perfect for the eclipse photographer that does not want to mess with a camera during totality. I used the TC80N3 during the eclipse of 2008, on a moving ship, in conjunction with a 400mm lens on a tripod. Although a large number of the images are not centered, most came out quite good. During totality I adjusted the base exposure and used a three shot burst +/- 1 f/stop.
Most modern digital cameras for professions offer timers and intervalometer interfaces.
Computer Driven Eclipse Photography
Computers can be used to run the camera. This means you are carrying along a computer of some sort, most likely a lap top. To connect the computer and camera, use the same cable used to move pictures from the camera to the computer. This is normally a USB cable.
Instructions are sent from the computer to the camera. Modern cameras support remote control with instructions such as setting the ISO, aperture f/stop, exposure, and file format details. Under the control of a computer program design for solar eclipse photography an entire range of images can be created.
Several programs can be downloaded directly from the web (listed below) and installed on your computer. I cannot stress strongly enough that practice and preparation time is needed. Not only do you need to adjust the programs to your own camera specifics (normally by changing parameter or script files) but you will also want to be as comfortable as possible when running the assembly during totality. Otherwise you could miss the eclipse fiddling with things at the last second.
Personal Experience: I've always run the camera manually during a total solar eclipse. The reasons are to reduce the amount of equipment to carry along as well as the general rule of thumb - keep it simple. During the Total Solar Eclipse of 2006 I handed control of the camera and telescope to another (our daughter). This allowed me to experience the eclipse like I've never seen it before (and this was my 11th total solar eclipse experience). Also, by bringing her along I could bring additional equipment. A Coranado hydrogen alpha telescope in this case.
2009 was my 13th total solar eclipse. Our daughter did not come along this time. Thus I introduced a lightweight piece of equipment to the process - an intervalometer. This tool performed wonderfully. It allowed me to watch the eclipse while the camera clicked away. Using the three shot burst I obtained a good range of images using a tripod mounted 400mm lens on board a moving ship.
For 2010 I used a small lap top computer to increase the ability of the remote control. The key to success, even with automated solutions, is to practice and make sure you fully understand every step involved (plus counter steps in case of problems). The software I was using did not synch properly with the GPS and the timings of the 2nd and 3rd contacts were off as a result. The rest of the program worked great - the ship moved a lot and I was forced to reposition the camera constantly but I could see that from a stationary position, this solution was optimal.
