Star Trails in Prague
Tips & Tricks

Astrophotography for Beginners – 9 Tricks & Tips on How to Shoot Night Sky and Stars

Why didn’t I shoot the night sky before? Well, I don’t want to make excuses, but the problem is that I live in Prague – the capital city of the Czech Republic. Here stars are virtually impossible to see because of the enormous light pollution. And when I’m on a trip in the mountains than at night … I usually sleep 🙂 But that changed on my last trip in the Krkonoše Mountains when I literally fell in love with the stars. First, let’s talk about what conditions are necessary for shooting a night sky. Then we will go through what basic equipment you need to have. Finally, we will discuss the camera settings and I will tell you some of my tips and experiences.

Hooray, here we go!

Night Sky & Stars Photography Tricks –  contents:

 

What are the best sky & weather conditions for astrophotography?

Weather is the basic factor you need to get right when shooting the night sky. If the sky conditions are bad, you simply miss your main object for astrophotography – the night sky.

Why light pollution sucks

The biggest obstacle when shooting the night sky is light pollution. What does light pollution actually mean? In a nutshell, it is any artificial light produced by humans – light from buildings, public lighting, etc. Therefore, it is virtually impossible to see a nice night sky with stars in cities. But do not be mistaken – it is often very difficult to find a sky full of stars even outside the city! However, there is a so-called light pollution map where you can easily find out where to go if you are serious about taking a night sky. Sure, there is no need to take things to the extremes – so just remember this: the further away from man-made light sources, and cities you are, the better! It pays off.

How moon phases affect the astrophotography

I bet you didn’t know how huge influence can a moon phase have on the lightness of the sky. So the less the moon reflects sunlight, the better for us. The sky will be darker, and the stars more visible. Of course, the best case would be when the eclipse of the moon is. But then we would not take many pictures, because such a situation occurs only 2 – 3 times a year 🙂 A period when the moon reverses or grows (only a small part of it is visible) is enough for us. So we have about one week every month – that’s not bad anymore, is it?

The best weather conditions for shooting the night sky

When it gets cloudy, there won’t be much to see either. But if the sky is overcast only slightly, it can give the photo the right atmosphere! The stars will shine through the clouds and the whole image will pop. In this case, it is certainly necessary to meet the two above-mentioned conditions – the right phase of the moon and be far from light pollution. Regarding the weather forecast, I like Accuweather.

The basic equipment you need for night sky & stars photography

Today it is possible to take nice photos of the night sky even with a good phone (thanks to special night modes). Still, compared to the shots taken with a DSLR (or mirrorless camera), it kinda sucks. Nevertheless, the following equipment can be used for both mobile phones and DSLR/CSC cameras.

4 basic things you need to have for astrophotography:

    1. A sturdy tripod (or at least place the camera on the ground and lean)
    2. Always shoot in full manual mode 
    3. Shoot in RAW format if it is possible (editing the photo will be much easier)
    4. Wide-angle lens (35mm or less) with good aperture (f/4 and faster)

A tripod is an absolute necessity because exposure time for night sky takes at least 10 seconds or more (since the sensor needs to collect enough light). Here, even the best stabilization won’t help you :). And be aware of wind or any slightest movement of the camera – you don’t want to have your photos blurry. If you don’t have a remote control for your camera, you can use a timer – so when you hit the shutter button, the camera won’t shake.

Why shoot in manual? Well, you need to focus on the stars manually (focus at infinity, but not literally), and manually set the ISO and shutter speed. Taking pictures in the RAW format is better for later editing the photos on a PC. 

Finally, a wide-angle lens is convenient, because it allows you to have a longer shutter speed without having the stars blurred (=> we are further away from the sky and the stars move toward our position). And the good aperture of the lens is useful for a similar reason – the sensor collects more light at the same time and the exposure is faster (again stars won’t be blurred).

Best camera settings for night sky photography

  1. Aperture should be between f / 1.8 and f / 4 (ideally f / 2.8)
  2. ISO 800 or higher (but I wouldn’t try more than 3200)
  3. Shutter speed 10 seconds or faster 
  4. Focus on infinity (or near infinity)
  5. RAW image format

Night photography is all about collecting enough light (in our case because of the stars / milky way clarity) while maintaining a reasonable amount of noise (because the longer the exposure, the more noise the sensor collects). Therefore, if you have a full-frame camera (or medium format), it is a great advantage when shooting a night sky. But this does not mean that it is not possible with APS-C (or even smaller sensor), the only problem is that there will be more noise in the photo. However, the noise can be reduced relatively well in the post-process. In practice, if you set the ISO to 3200 on a full-frame camera, the photo may still look good at a 15-second exposure, but the result for the same exposure with an APS-C camera may be unusable. What to take from it? Increasing ISO is the worst way to lengthen the exposure.

Therefore, having a wide-angle and light lens is a big advantage. This allows you to collect light onto the sensor faster, and prevent having blurry stars. Combined with a full-frame camera sensor, it is a killer for night photography. It is not a necessity, but there is nothing better.

Speaking of the camera settings I mentioned above, it is rather symbolic. As you already know, except for sky and weather conditions, the settings highly depend on the lens type, sensor type, and of course, the camera itself.

All three basic camera settings – aperture, ISO, and shutter speed have to be adjusted accordingly to the camera itself, weather, and light conditions. Therefore, it is necessary to experiment.  If the stars are not clearly visible in the photo, extend the aperture or extend the shutter speed from 10 to 15 seconds. If this does not help, increase the ISO. Let me repeat it – experiment. Are you afraid of manual mode? There is no reason to be so. I also use the full manual exceptionally. And believe me, there is no hurry at night – you have plenty of time for everything :).

The 500 rule

For those of you who want to have a specific guide/tool right at the beginning of these experiments, let me introduce you to this simple rule from astrophotographers – the 500 rule. There is science behind this rule, but we’re only interested in the essentials, and these are the two formulas below:

For full-frame cameras:

500 / Focal Length = maximum exposure time

For APS-C cameras:

500 / Crop-Factor x Focal Length = maximum exposure time

Examples:
If you have a full-frame camera and lens with a focal length of 24mm, the formula will be: 500/24 => about 20-21 seconds of exposure. This is a time when stars should not be blurred. The ISO value is assumed to be around 3000. Simple, right?

If you have an APS-C camera and a lens with a focal length of 24mm, the formula will be: 500 / 1.6 x 24 => about 13 seconds of exposure. This is a time when stars should not be blurred. The ISO value is assumed to be around 3000. Remember that the crop factor varies from manufacturer to manufacturer. Nikon APS-C cameras have 1.5, while Canon 1.6 and Olympus 2.0 (Micro Four Thirds System – smaller sensor than APS-C)!

How to shoot the Milky Way

The same rules apply for photography of the Milky Way as for stars and night sky photography. It is only necessary focus even more (MUCH more!) on all the factors I have mentioned. You especially need to have a dark sky as much as possible. And since you can’t see the Milky Way with the naked eye, it’s a good idea to help yourself with the mobile app. For example, I use Stellarium. In just a few seconds, this app will help you navigate perfectly (more about this app below).

Astrophotography of view of the Milky Way at Plešné Lake
View of the Milky Way in the Bohemian Forest

How to shoot star trails

What are even star trails? As you might know, the stars are always slowly moving toward our viewing position. If we want to catch the motion of stars, we would try to capture so-called star trails. 

If you want to capture star trails, you need to follow all of the rules described above. However, you have to use a longer shutter speed of at least 30 seconds or more. But that is not the trick. If we only took a single picture with this shutter speed, we would hardly capture the motion of the stars – it would be barely (if even) visible in the picture. Therefore, you must use one of these two basic techniques to capture the motion of the stars during the night.

 

Technique 1:

The simplest option is to have the shutter open for several minutes (about 10 minutes or 20 minutes and more). The motion of the stars will be much more visible. But the problem with this technique is that the camera collects a huge amount of noise and movement at the same time (especially in the case of APS-C). I do not recommend this method.

Technique 2:

The second option is perfect, but a little bit harder. We need to use interval shooting to take tens (ideally more than a hundred) photos each with a shutter speed set to 30 – 60 seconds. We select an interval shooting mode in the camera (differs from camera manufacturer), set a pause of 1 second between frames and set the shooting time to 1 – 3 hours. You will then end up with dozens of photos, which you later blend in Photoshop (down below, I will learn you how). This method avoids having a huge amount of noise in the final picture that you’d otherwise had.


Surely, you’ve seen star trails photos where all the stars seem to spin in a circle. For this type of photo, you’ll need to find the star Polaris (the brightest star in the constellation Little Bear) in the sky. This star is not significant for its brightness, but its position in the sky. Whether it is evening or morning, whether it is winter or summer, Polaris is always in the same place and the other stars revolve around her. The Earth’s axis of rotation, which causes the apparent movement of all the stars in the sky, passes almost precisely through the Polaris, causing its statics. How to Find Polaris in the Sky? I’ll give you the same advice as in the Milky Way – use Stellarium mobile app (or google how to find the constellation Little Bear).

Night Sky in Prague - Star Trails
I took this picture above in Prague. Yes, exactly - in a city where light pollution is extreme. But I waited for the right time when the sky was clear and the moon was hidden.

Personal tips for night sky shooting

  • To be honest, even though photography at night is still photography, it is definitely more physically and mentally demanding.
  • Since I assume that you are going to take pictures somewhere in nature, it is necessary to carry a headlamp or flashlight with you (or use at least a flashlight in your mobile!). If you keep the camera close to the ground (for a more interesting composition), be prepared that handling and adjusting the camera will not be fun.
  • Just like focusing on stars. It is said that focusing on infinity should do the trick, but often this is not the case and you need to focus the lens a little closer (depending on the manufacturer and the specific lens). There is no bigger fail than if you find out that you had poor focus after a few hours of shooting at night. Therefore, it is recommended to focus (and generally adjust the camera) before it gets dark. But … I personally always give up and do everything on the spot 🙂
  • Try to be creative. You will soon find that taking a picture of the night sky is not difficult, so focus on the part of the composition under the stars. Whether it is a lake, mountains or whatever. Use the so-called light painting method – that is, you can illuminate part of the photo under the stars with a flashlight (or flashlight on a mobile phone, as I do). This means taking one more exposure – you then blend this photo with a correctly exposed night sky photo (s).
  • Use the polluting light to your advantage. Paradoxically, it can give the photo an interesting effect and pop it. See an example of my photo below where I used both the cone of light that shone from the city and the huge amount of general polluting light itself.

How to edit night sky photos

When it comes to night sky photography, I’m just a beginner. And it is the same with editing such photos. However, the basic principle is simple – the goal is to create a contrast between the stars and the sky. So move the blacks to the left to darken the sky, and whites to the right, it will highlight the stars. At the same try experimenting with temperature settings – range between 3400 and 4600 should do the work. Don’t forget the part of the photo (foreground) where there is no sky. There, you will need to lighten this part – move the shadows to the right. If this is not enough, increase the exposure or use radial/ filter.

The best thing to do is to create more than one variant – right-click on the edited photo in Lightroom and press “Create a virtual copy”. This will give you another copy of the photo – in the first photo, adjust the photo so that the stars and the sky stand out, and in the other on, the bottom of the photo. You can then compare both of them and choose the best one.

For maximum control, use Photoshop if you can play with luminosity masks. But this is an advanced technique that can be relatively time consuming – talking about it would be enough for another long tutorial 🙂

When editing star trails photos, the most effective method is that you first edit these images only slightly in the Lightroom (edit the first photo and synchronize with the others – “Sync” button). Then open them in Photoshop as layers (select the “Open as layers in Photoshop”). Once you have uploaded photos to Photoshop (this may take a while), you should align the photos. Select all layers and click “Edit” in the top bar and select “Auto-Align Layers”. This may take a very long time to process if you have uploaded dozens or more photos. Once the operation is complete, change the “Normal” blending mode to “Lighten”. And the magic is done 🙂

Handy mobile apps for astrophotography

Google Earth is generally a great app that is worth mentioning. It’s free and allows you to perfectly explore the place you want to take pictures. With a 3D view from satellite imagery, you can easily plan ahead with the composition you need. It’s a sin not to use this fantastic app 🙂

The Stellarium app is made for observations and photography of the night sky. It is irreplaceable. With this app, you can see and identify the location of stars, planets, and constellations (and many other objects) in real-time! Thanks to the GPS module on your phone, you just need to point the phone to the sky.

How to find the darkest sky the easiest way? Dark Sky Finder. Remember that light pollution is the number one enemy in the astrophotography. However, I do not consider this application a necessity (usually it is enough to use common sense and move away from civilization).

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