Recent Amateur Astronomy Images

Saturn occultation

These images of the Saturn occultation were made by Rik ter Horst on November 12th 1997 around 1:30 UTC. He used a 5" Opticon SCT130 Schmidt-Cassegrain telescope and a Canon UC8 Hi8 camcorder. The camcorder was pointed into a 50mm eyepiece and zoomed in on Saturn. The images are single frames taken from videotape using a Snappy framegrabber. Rik designed and built this telescope himself.

saturn color

This image of Saturn was made in November 1997 by Rik using the same method as the above images. The telescope that he used this time was a homebuilt 8" (205mm) Kutter telescope (catadioptric). Because of the extreme contrast and the bigger mirror there is colour visible even in this single frame (40ms exposure) ! You can see a belt around Saturn and the Cassini division can be glimpsed. Look at the subtle color differences between the planet and the rings! No image processing was used on this image. The telescope has no drive and the camcorder was handheld.

saturn 2 color

This image of Saturn in August 1998 was also made by Rik using the same method as the above images. The telescope that he used this time was a homebuilt 10" (255mm) schiefspiegler telescope of his own design! The telescope has only two mirrors and no lenses at all. No drive was used and the camcorder was handheld. The left image is unprocessed, the right image is slightly unsharp-masked. Again a single frame taken from the Hi8 tape with Snappy. Notice that the rings are more tilted towards us compared to last year.

9 merged frames Rik's sandwich

This last image is a combination of nine different videoframes. This equals a 0.36 sec exposure. By combining frames, (random) noise from the single frames is eliminated and contrast enhanced. As you can see, this is the complete camcorder picture (full frame, no cropping). It is quite difficult to align them accurately, but with the help of software like Aldus Photoshop it can be done. The image was unsharp masked with Corel Photopaint after combining the seperate frames. Sharpening induces some noise again, but the result is quite pleasing. Notice the subtle intensity differences in the ring. The image on the right was composed by Rik with the same technique, using some extra image processing.

jupiter sandwich

After getting used to this technique, I took some old video recordings of Jupiter that I made in 1990 and used Snappy to get seven frames. After combining, an unsharp mask was used to enhance details. I was surprised to see so much detail in the resulting image.... Telescope: 10" (255mm) Newtonian with 25% linear obstruction, Ikegami surveillance CCD (0.5 Lux), and a Sony SLC1 Betamax recorder.