Titan & Iapetus orbiting Saturn through my 200mm lens

This video showcases time-lapse animations of some of Saturn's moons orbiting Saturn, created by combining the images I took between the end of 2020 and the beginning of 2021. Each image shown throughout the time-lapse animations is actually created by stacking hundreds of short exposures in a computer environment. This process aims to increase the signal-to-noise ratio, thereby bringing out faint moons and stars. The durations of these short exposures vary between 2 and 3 seconds.
The term "200 mm" mentioned in the video title should not be confused with the commonly encountered telescope diameter. It refers to the focal length of the lens. However, we can easily calculate the aperture diameter of the lens as well: Diameter = Focal length / F_number = 200 mm / 5.6 = 35.7 mm.
The image scale per pixel achieved with my camera and lens combination is approximately 4.4 arcseconds per pixel. However, this value does not indicate that the image is diffraction-limited because the calculated angular resolution (angular diameter of the Airy disk) for the wavelength of 550 nanometers and the diameter of the lens aperture is about 3.87 arcseconds.
Since the distance of Saturn changes over time, the distance values in astronomical units (AU) given in the video also change. However, these values remain between 0.015 AU and 0.020 AU throughout the duration of the time-lapse animations (the first two one).
Here, the visible disk of Saturn is not its actual size. To avoid blowing out the planet and thus to achieve the true size of the disk, much lower exposure values should be used than those in the video.
The images were taken in an area with a Bortle dark sky scale rating of 9 (Istanbul).
The images in the final parts of the time-lapse animations have a low signal-to-noise ratio, fewer visible stars, and a lower limiting magnitude. This is due to the orbital configuration of Earth and Saturn at that time, aligning such that the Sun remains between them. As a result, Saturn appears to move closer to the Sun in the sky each day. This means that with each passing day, Saturn needs to be photographed against an increasingly brighter sky.
Some days are missing due to unfavorable weather conditions and the reason why Saturn's disk appears in different sizes each time is due to different numbers of exposures being stacked.
Saturn's axial tilt is similar to that of Earth. This means that, like Earth, Saturn shows different parts of itself to the Sun and Earth along its orbit. Since Saturn's equatorial plane is tilted relative to its orbital plane, the plane in which its moons are located is also tilted in the same way, as Saturn's moons orbit around its equatorial plane. This is why, at different positions in Saturn's orbit, we sometimes see the plane of Saturn's rings and moons from below, from above, or edge-on. If there were no axial tilt or orbital inclination at all, we would always see this plane edge-on. In the video, we have a perspective looking down on this plane.
Music by CO.AG Music
Composer's channel: / @co.agmusic
Link to the track: • Futuristic Sci-fi Elec...

[@jonruffolo]

wow this was fucking dope dude. last shot of the stars passing by saturn gave me chills.

[@cemderenbilgili]

Thanks! I specifically zoomed out so that we could see how the stars and Jupiter move in a reference system where Saturn is at the center. Hope the rest was just as good for you🌟🪐