The first step to capturing an ISS transit is to find the time and location of one near you. You can do this using http://www.transit-finder.com. Transit-Finder is free and helps you find ISS transits near your location within as specified distance and within a specified duration. Check out the video above to see how to use transit-finder effectively.
Here are a few tips to help you with your first capture:
- Reach the location early so that you can ensure you have line of sight to the Moon or the Sun
- Ensure you take care of your personal safety – that the location is safe for you to visit at the time of the transit
- Take some time to take trial shots of the Sun/Moon prior to the transit so that you can adjust things like exposure and focus. Focusing the sun can be especially tricky because of the ambient brightness, a hat or cloth to block out the sun while you look at the camera screen helps
- Ensure you take all precautions if you are capturing a solar transit. Remove finder scope completely or ensure it is completely covered. Always use an aperture filter from a reputed brand. Check this video for more details on how to safely view the Sun with a telescope – https://youtu.be/CuJGddSUzfs . Remember – NEVER look directly at the sun with or without a telescope and always seek help from someone who is experienced to avoid irreparable damage to your eyes and to avoid accidents.
- When it comes to the capture itself, ensure that you take a video at the maximum frame rate possible – if you try to take a snap shot or photograph in burst mode, you might actually miss the capture. Transit-Finder is quite accurate but you can start recording about 2 minutes prior to the predicted time (remember to sync your time correctly). You can extract the required frames using PIPP – which I will cover in another post about processing transit images. Remember – maximum frame rate for the video – minimum exposure length per frame to ensure that the final images of the space station are not blurred.