Night sky photography using long exposure is a fascinating category of photography. It is creative and fun which gives perfect satisfaction to the photographer. Though long exposure photography sounds tough and complicated especially for night sky photography, this is easy and interesting. Let’s go outside and have some long exposure shots following the easy steps discussed below.
Night Sky Photography: Know Before You Go
Before we go outside for taking long exposure shot at night, we must consider a few important things about the outside environment. If we want to make a shot of stars or galaxy for night sky photography we should consider the following points:
1. A Sky Without Clouds
If we’re going to take the stars or galaxy in our frame then apparently we have to have no visible object between our camera and stars/galaxy. Again it depends whether we want to keep an object to make the photo more beautiful and thus changing its meaning.
2. A Place Free Of Light Pollution
For night sky photography we have to keep in mind that we will be capturing a minimal amount of light provided from the sky. So, if there is a presence of light which is brighter than the objects to be photographed of the sky then definitely the strength of the skylights will be reduced which will make a miserable night sky image. In some cases, the pollution will spoil the photo.
3. A Place Which Is Stable
You must ensure that the place where the camera will be set is stable. That means during the whole process, there should not be any movement of the camera caused by the area. For example, a camera placed on a boat is not a stable platform for this type of photography.
4. The Position of the Moon or Phase of the Moon
As we are considering only the stars/galaxy, we have to keep the position of the moon in consideration. For this type of photo, the moon will act as a source of light pollution. How can we know the location of the moon? We can Know the position and size of the moon including the time it will remain in the sky if we know the moon phases.
However, there are many apps found in both the Google play store and apps store which can show the position of the moon. In many apps, the location of all the stars, planets and their satellites are shown. For example ‘Star walk’ is an excellent app where you can see the real-time position of all the stars, planets and their satellites.
Take Necessary Accessories and Aids
Before going outside; we must take the necessary and appropriate aids for the primary operation. Lest start one by one:
1. Camera Selection
We have to take a camera which can provide the option of a higher ISO range like 3200, 6400 or higher. It has to have a capability which can be remotely clicked. It is not that necessary to have the capability/ feature of the camera because we may use a timer. A full frame camera is recommended for this type of photography; however, it is not mandatory. Before taking a camera, we have to ensure that it can be operated under manual mode.
2. Selection of Lens
The lens plays a vital role in this night sky photography. We must remember that we are shooting the photo at night where there is very less light and we have to take the light emitted from the stars or astronomical bodies. So, wider the lens, more is the amount of light source as it is covering many areas.
At the same time, we need to take a wide aperture lens which will provide a better image as it will take much more light. Recommended aperture ranges are f/2.8 or below; however, f/3.5 or even f/4.5 is also suitable for this night sky images depending on the exposure time and the amount of light present on the object.
We should try to use a remote for night sky photography in long exposure mode. Nowadays most of the cameras have wifi facilities using which we can connect it with mobile phone or laptops and use that we can control the camera remotely. So this can be used if your camera supports so.
If you don’t have any of this then nothing to worry. You need to use the timer (maybe two seconds), then the camera will itself do the pressing of the trigger, and the process will start. Why should we use the remote/phone/laptop/timer? Because pressing trigger manually will cause the camera to shake and thereby the image will be spoiled.
Tripod is a must for this type of photography. One slight movement of the camera will destroy the photo. One small movement of the lens will change a vast area of the object area as it is too far from the object. If there is a possibility that the tripod may move then, we must use some weight to make the tripod stable.
It is recommended to use a better quality tripod. Again it’s not compulsory to use a tripod if you can place your camera firmly. But it is not that easy to get the desired angle or frame without a tripod.
Let’s Go Outside and Do It
Ensuring all the points above discussed you could go outside. So what we need to do after going out?
1. Set your time
At first, set the time by checking the position of the moon (as the presence of moon will cause light pollution) and the exact time to get the stars, i.e., galaxy in the perfect position using different apps.
2. Bulb Mode
Select the mode of your camera into bulb mode as you are exposing the camera sensor more than the usual one. If your camera is in bulb mode, then the shutter will remain open till the time you keep the trigger pressed. The exposure time depends upon the amount of emitted light, camera configuration, lens and the desire of the photographer that how long he wants to capture if he has got some other intention or plan.
However, most of the cameras have 30 seconds of exposure time in manual mode. So we can use that if we want to take a shot less than or equal to 30 seconds. In that case bulb mode is not required.
3. ISO Selection
Selecting the ISO is essential. We know an increase in ISO increases the noise. Again selecting low ISO will not allow the camera to take a sufficient amount of light for this type of photography. For night sky photography, pick a bigger range of ISO, but you should not choose it very big which spoils your photo.
If you have a lense where there is an indication of infinity then take your focus indicator there as the object is too far from the lens. In case of a lens having no infinity marking you can go outside during daytime in the place where you have planned and set your camera there. After that focus the sky and then turn the focus mode from auto to manual and don’t make any change to the lens.
5. Sealing off/ Blocking the Viewfinder
It is not so important to seal the viewfinder. It is mainly required for long exposure photography during the daytime. However, sealing off the viewfinder ensures no leakage of light through the eyepiece if there is a presence of a light source behind the camera.
If the place from where the night sky image or night sky photography will be taken is entirely dark, then there is no requirement of sealing off the viewfinder. So, how can we seal off this viewfinder? We may have noticed that there is an extra rectangle plastic portion with the strap of the camera.
We can place/fix it with the viewer by removing the rubber protection attached to the eyepiece. Just merely press in both the side with the finger and pull it up, the rubber portion will come up and then fix the rectangle sealer with the strap in it.
6. Pressing the Trigger
Pressing and releasing trigger is the final job to be done in this whole process. After focusing on and completing all the steps mentioned above, we have to press the trigger utilizing remote or any other means discussed before. Now, how long we should keep the trigger pressed or what should be the exposure time?
This depends on the amount of emitted light from the object; ISO selected and the aperture of the lens. We have to take such an exposure tenure so that it does not overexpose the image at the same time receives a sufficient amount of light to make the image a desired one.
Again the question may arise that how will we understand whether this is going to over or underexpose the image. After the full setup, we may take two or three shots with different exposure time, and the comparison amongst those photos will give the idea about the perfect exposure time. That’s why it is said to practice brings perfection. Usually, an exposure more than 25 seconds will star trail.
For any photography, be it night sky photography or any other category is written rules or tips are just a guideline. Whatever mentioned above are nothing but necessary for making a night sky photography or image using a long exposure. Following these few steps, we have to go to the experiment and automatically we will understand what to do next.
We have to realize that both mistakes and successes are experiences for us. They always teach us by correcting or inspiring. So no more waiting, follow the steps and go for it. I firmly believe that if you take ten photos using these guidelines, then you will realize the whole mechanism of night sky photography.