Astrophotography holds a significant fascination for me. The night sky has an awe-inspiring quality that never fails to amaze. The recent Perseids meteor shower was a spectacular event. Despite my efforts to capture it, I often found myself pointing the camera in the wrong direction, as did many others. Lacking a wide-angle lens, it was challenging to encompass enough of the sky.
Many of us have successfully photographed the Moon, achieving impressive results. However, photographing stars and deep-space objects is a completely different challenge. It's crucial to account for the Earth's rotation; long exposures needed to capture dim light mean that by the time the exposure ends, the Earth has moved. This movement makes the stars seem to shift, leading to a blurred image in the photograph. You can see evidence of this in the photo below.
To counter-act this, we need our camera to be turning at the same speed as the Earth so that our images will always be in focus. There is equipment available called Star Trackers but they tend to be rather expensive.
Alternatives do exist. If you're skilled with tools, you can create your own. I chose to build mine using a 24-hour timer, assuming the mechanism completes one rotation every 24 hours, approximately mirroring the Earth's rotation. Here's what I devised:
I acknowledge that my creation may not match a professional one. The mechanism isn't designed to support a lot of weight, but it should suffice as a proof of concept for a brief shoot. The maximum exposure time I envisage will be 10 minutes. As long as it holds together for that amount of time we should be good! The small tube depicted in the photo is used to align the machine's axis with Polaris, which is seemingly the sole calibration required for this kind of tracker. Polaris, being the celestial North Pole, is the pivot around which all other stars seem to revolve. Once it's aligned, the camera can be directed towards any area to capture images of the subject. Now, I'm simply awaiting clear skies to test it.
As I awaited a clear sky, I took the opportunity to enhance my setup by adjusting the ball-mount for a better grip, preventing the camera from slipping. Additionally, I painted the MDF parts and am quite satisfied with the new appearance.
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