There are times when you might want to consider doing astrophotography without tracking. These are as a beginner when you don’t have the equipment and are wondering how to get started, or if you are traveling somewhere without all your equipment. Is it possible to do astrophotography with a camera and tripod and no tracker?
You can do astrophotography without a tracker by attaching a DSLR camera to a sturdy tripod. This will limit the length of your exposures to 15-20 seconds with a lens of 17-24mm, stacking hundreds of photos will create a good image of the Milky Way. Deep Sky targets need bigger lenses and shorter subs.
We do need to look into this question much deeper because there are many variables that can make astrophotography harder without a tracker. There is a lot more to answering this entirely so stick with me, this page is filled not only with what you need to know but what I have learned through my own experience and research into this question of tracking.
Why do We Use Tracking?
The reason we need tracking is that the objects in the sky are moving, generally from East to West depending on where in the sky the object or star is. This movement is because our planet is rotating around a point in the sky called the Polar Axis. In the Northern Hemisphere, where I live, stars and other objects in the sky appear to rotate around a point near Polaris, the North Star.
In order to counteract the rotation of the stars we need to use a tracking mount that follows the movement of the stars and moves in the opposite direction to keep the object in the centre of the field of view.
The reason we use tracking is to use long exposures to photograph faint objects in the sky and capture their fine details over many hours. Without a tracker, we will get star trails and blurry images with less detail. Most telescopes, but not all, are sold with a tracking mount but you can also buy a portable tracker such as the Sky-Watcher Star Adventurer.
Astrophotography without a tracker is only possible for very short exposures and certainly not longer than about 30 seconds.
My research into this revealed that I could take up to 20-second exposures with a 17 or 24-mm lens on my DSLR, a Canon 600D with no tracker as I attempted to image the Milky Way. This was possible because my target was generally high in the sky. I couldn’t see any trailing in the stars despite not using a tracker.
In March 2022, I went to Bali and experimented with astrophotography using a 50mm Focal Length lens and DSLR with a tripod to photograph the Orion Nebula and Horsehead Nebula. I took 435 x 5-second exposures. Although the picture came out brilliantly on close inspection zooming in the stars were trailing slightly even at 5 seconds of exposure!
When I photographed these two objects I noticed they were low on the horizon and eventually were heading towards setting. This may have been a reason why even 5 seconds without tracking was still causing small amounts of star trailing.
What is your Astrophotography Target?
Whether or not you can image the night sky without a tracker depends on your target. Some targets, such as deep sky objects such as galaxies and nebulae are so far away that they are extremely faint so hours of integration time are usually necessary. For extremely difficult-to-image targets, it is best to use longer exposures in the minutes to get a quality image but you can image these with much shorter untracked images if you take hundreds or even thousands of photos.
The target mentioned above, the Orion nebula is very bright and not so far away, so short exposures can work. So to capture these kinds of bright targets you do not need to use tracking.
Galaxies, apart from Andromeda which is both massive and can be seen with the naked eye in dark skies, need longer exposures of one minute or more and several hours of exposure.
A Helpful Video about untracked astrophotography imaging is this one by Nico carver:
What Camera and Lens Will You Use?
If you clicked on the link above and watched Nico Carver’s video, then you’ll have already heard him discuss the equipment you need for this kind of astrophotography but read on because there is a lot more to come from my experience taking astrophotos without a tracker.
To do astrophotography without a tracker is usually easiest with a DSLR camera and lens. The reason is that a camera and lens usually weigh less than a telescope and camera and therefore can sit comfortably on a sturdy tripod. A telescope is heavy and long and usually needs to be well-balanced on a mount that can also include a tracking motor.
If your lens is below about 200mm focal length you can usually just point and shoot. There is no need to locate carefully objects in the sky. Also, the lower the focal length, the less obvious will any star trailing be in an image.
It is possible to image with as low as one-second exposures and provided you have a sufficiently large number of images, you can do this without tracking. The problem is you will have thousands of images that are difficult to store and will take a long time to stack, but it can be done.
Is it Possible to Use a Telescope without Tracking?
Yes, it is. But is this practical? My telescope has a focal length of 650mm and so the longest I would be able to expose without any tracking could be as low as one or two seconds. My experience is that I’d need many images and the result could never be as good as with longer exposures of a minute or longer each. My recommendation is don’t do it. Stick to widefield DSLR and lens only.
The 500 Rule
If you plan to do astrophotography without tracking you need to know how long you can make your exposures to avoid any star trails. The formula to do this is called the 500 rule.
Simply divide 500 by your focal length and this will tell you how many seconds you can expose without star trails in your image.
To be on the safe side the third column in the above table would ensure that your stars are sharp and round with no trailing.
If you’re just trying astrophotography for the first time or if you have not got your trusty tracker with you, you can still enjoy astrophotography without a tracker. Just be prepared for lots and lots of images at really short exposures! Clear skies!