Starting Star Photography – A Basic Guide
Starting Star Photography – A Basic Guide
Star photography is beautiful, capturing the universe for one moment in time. Knowing that the flickering lights on the image have taken thousands of years to reach us and are now preserved forever. Finding a dark sky is essential and allows the stars to appear beyond the usual bright stars seen in towns and cities. Usually Orion’s Belt and The Plough are visible, dominating the sky, but in a dark sky these constellations are the first to appear as twilight decreases, but as true night appears they fade into the sky amidst the thousands of stars.
Star Photography Quick CheckList
- Choose your location and ensure your tripod is stable
- Make sure you are safe
- Identify where in the night sky you need to be looking
- Remove all filters and switch off image stabilisation
- Reduce the LCD brightness and ensure RAW format files are selected
- Switch focus and exposure settings to manual
- Plug in your shutter release cable or set the self timer to 2 seconds
- Frame your shot and focus manually using live view where possible
- Know the maximum shutter speed for your selected focal length
- Set the aperture as wide as possible f/1.4 or f/2.8 if possible
- Set the ISO to 800 or 1600 but be ready to adjust it
- Enjoy your evening under the stars
Cloud Free Skies
In the UK the dark sky areas are limited but Dark Sky Discovery website provides loads of relevant and useful information including some overseas sites.
Before looking for stars it is worth checking the cloud cover.
With clouds nothing is visible and it is not worth getting off the sofa beyond opening another bottle of wine.
I use the met office cloud cover for data and while it isn’t pinpoint accurate it gives an idea of a time to set the alarm.
Finding the Stars
Finding the stars is also useful and the skyview app is brilliant for working out what you are looking at.
The other that is really useful is to know when the moon is going to rise and set. A bright moon can over power the stars, again making a trip less than productive.
So, assuming it is dark, there is minimal light pollution and limited moon light and cloud cover it is time to head out and attempt some photography.
The Basics OF STAR PHOTOGRAPHY
There is lots of information out there so this is a brief introduction and a start.
Some cameras have a built-in star mode and this is good, but nothing beats playing with the exposure settings yourself.
Location
The first challenge is to find a suitable spot.
Interest in the foreground is useful.
A sky of stars is beautiful but doesn’t give any idea of scale.
Movement
A tripod or solid support is essential.
All of the images will be taken using a long exposure.
It is not possible to hold a camera still for 15 seconds however steady you think you are.
Whilst movement can be useful in star photography it is not what is needed.
Movement can also happen as you press the exposure button so a cable release or using the built in timer are essential to reduce the chance of movement even further.
LCD Screen Brightness
Once the camera is switched on I always turn the LCD screen brightness right down.
In some cameras there is a night photography screen option.
Either way, a LCD screen on normal daylight view will show the preview image looking fantastic, but our eyes are not adjusted to the darkness and so the resultant image will be pitch black (under exposed) – a real disappointment.
Capture in RAW AND REMOVE FILTERS
I also capture all the images in RAW so I can have the maximum flexibility in post-processing.
With a JPEG file the camera does what it thinks is required which is not always right in star photography.
I also remove all filters and have auto white balance set. I don’t fiddle with any other settings in the menu!
Focus
The next challenge is to focus the camera.
I usually find a light as far away as possible and focus on that manually.
If there is no light, a torch as far away as you are brave enough to walk work equally well.
The other options are to focus the camera on autofocus in daylight to the furthest point visible and then switch to manual and not touch anything or use the infinity setting on the focus rings.
Either way, an unfocussed image is not what we want. I have also found that using live view and magnifying the image makes focussing much easier. Some cameras have this option and it is worth using if you have it.
Exposure Settings and Focal Length
Settings are probably the easiest part of the photography as image review will give a rough indication of what is happening.
Ideally f/1.8 or 2 will require low ISO and a shorter time, but star photography is possible with higher f-stops, however time and ISO will need careful consideration.
What is needed is a wide-angle lens to show as much of the sky as possible and the highest f-stop (smallest number) available to let as much light into the sensor as possible. Again, while a sky of stars is beautiful the foreground helps to make the picture.
Moving Stars
The exposure time needs to be quite long, but care needs to be taken as stars move and depending on the focal length movement will be seen. This can be calculated and is known as the 500 rule.
As an example 500 divided by a 24mm lens give 20.8 seconds or a 20 second exposure.
Above 20 seconds and movement of the stars will be visible.
This needs further adjustment if a cropped sensor is being used to take into account the cropping.
At 24mm the exposure time needs to be under 15 seconds to prevent movement being visible.
ISO Adjustment
Once the shutter speed and f/stop has been set, these can be left alone.
The adjustments can all be done on the ISO. The ISO needs to be increased whilst not jeopardising image quality from noise.
This is again trial and error.
I usually start with an ISO around 800-3200 depending on how dark the sky is. With a full moon the ISO can be as low as 600.
Moving the ISO up and down will alter the exposure and over time it is possible to judge a rough ISO from the outset.
Post-processing
These settings are a starting point and can be manipulated to give star trails with longer exposures and stacking multiple images or stitching images will give a wider view of the night sky.
Once the image has been captured, manipulation is essential in post processing.
I take photographs and check them on the preview screen but none are deleted until they are viewed in post-processing as they look totally different on the big screen. Don’t be tempted to delete anything before you see it on the big screen.
Processing will allow the highlights and shadows to be controlled, in RAW the image has to be manipulated to some extent regardless of how good it is.