This tutorial is made by Paul Ibbitson. And below is the picture of star trail he took with DWARF 3 smart telescope.
The art of creating star trails is actually really simple. The apparent motion of the stars across the sky is due to the rotation of the Earth. By placing your camera in a fixed position means that you can capture this motion by taking lots of long exposures and stacking them in software.
Equipment:
• Dwarf 3 smart telescope.
• Tripod: Nice and sturdy.
• Ball head (this is optional and certainly not a requirement).
• Small power tank: to keep your Dwarf 3 from running out of power.
• Hot beverage: Whatever takes your fancy.
Pre-Planning:
To start with, if you want a foreground object like a building or tree line then the first thing to do is a bit of research. Star trails can be created in any direction, but if you want to capture the iconic "vortex" then your Dwarf 3 needs to be pointing to the north star, Polaris. (See below in blue for the southern hemisphere).
By searching for your subject on Google Maps first you will give you an idea of which way your subject is facing. You will then be able to work out where you can (or cannot) set up. You can also work out which way you will face and in turn which way your star trails will go.
Once you are happy that you can see north and that you have a good idea of where you will set up it is a good idea to keep an eye on the Moon phase and position on the night that you want to image. The Moon is great for lighting up your subject or any surrounding landscape without the need to light it up with artificial light.
If you can, try to arrive in daylight or during sunset so that you can set up while you can see what you're doing. If this is not possible then remember to take a decent head torch. Make sure that it has a red setting as this will preserve your night vision especially if you are setting up in the dark.
Step 1:
The first thing you need to do is find the best vantage point to place your Dwarf 3. To get perfectly round star trails you will need to place Polaris as near to the centre of the image as possible, so take this into account when setting up your tripod. Attach your Dwarf 3 to the tripod.
If you are in the southern hemisphere then you need to find the star Sigma Octantis. This star is not very bright so you will need to use the atlas in the DwarfLab App to find it.
As the Dwarf 3 wide lens has a wide field of view then you just need to point the Dwarf 3 in this general direction to get the classic “vortex” trail circle.
Step 2:
Frame up. As mentioned earlier, if you have a foreground subject or picturesque landscape, ensure that it is to the bottom of your image. You could also place the subject to the left or right of the image if you so wish.
Take a few test shots and see which works best and make sure that you're happy with the framing.
Step 3:
Turn on and connect to the Dwarf 3. Once connected click "Photo" to be taken to the live view.
Now click on "Photo" in the right-hand panel and select "Burst Mode" from the box that appears.
Step 4:
Now that you are in Burst mode the first thing to do is to click on the wide lens preview box to make the wide lens the main image on the screen, then click "Function" and select the wide lens in the menu.
Step 5:
Select "Parameters" and set the shutter time to at least 30 seconds and set the gain to 0.
Step 6:
Now click "Settings" next to "Parameters" in the menu and set the interval to 0 and then set the amount of pictures you want to take.
An hour is usually the minimum so at 30 second exposures, you will need 120 for an hours worth of star trails, or 240 for 2 hours. The more you take, the longer the trails will be in your final image.
Once you have collected all of your data then its time to pack up and head home.
Once home, download all of the exposures to your PC and put them through the software.
StarStax is renowned for being the easiest and quickest and it is Free!!!
https://markus-enzweiler.de/software/starstax/
Just drag all the exposures in, select "gap filling" then click the "start processing" button. It will stack your images and you will see your trails getting longer as you watch. Once that's done, save the image and process it in image editing software of your choice.