Astro-photography tips for sharp Milky Way images

Andrew Code

The best times for Astrophotography season are just around the corner. Every year between February and the end of October photographers in the USA get excited about photographing the Milky Way core at various positions throughout the sky, depending on what part of the season they are shooting it.

Planning to be shooting in the right conditions, and knowledge of some basic techniques will go a long way with astrophotography. Follow along for some tips and tricks for capturing sharp images of the Milky Way!

Equipment Planning For Astro-Photography

Astro-photography brings us shooting conditions that are often far from home, outside of city boundaries, late at night or very early in the morning when most of us would generally be likely to be in bed sleeping.
A bit of prior planning and preparation of your gear will help make sure your late night trips to the middle of nowhere go smoothly. Here is a quick checklist of things we recommend.

– Full frame, APS-C or Micro 4/3 camera that can handle ISO settings of 3200 – 8000 with limited “noise”
– Wide angle (16mm and wider) Lens with a minimum aperture of f/2.8. You can shoot astro images at narrower apertures like f/4 but we recommend at least f/2.8.
– NiSi Natural Night Filter to cut through any light pollution haze
– Stable tripod. This is very important. Not all tripods are created equally.
– Spare memory cards
– Spare batteries or even a battery grip that can hold at least 2 batteries.
– Remote shutter or camera with in built intervalometer that can handle less than 1 second in between frames.
– Head torch
– Warm, weatherproof clothing
– Food / Water

Use “Manual Mode” to take full control of the camera setting

When shooting the night sky it is important to take full control of all of the major exposure triangle settings – exposure time, ISO, aperture. Taking images of the Milky Way core requires a longer shutter speed, higher ISO settings and wide apertures – typically the exact opposite of many landscape photography opportunities during the day!

One of the key factors in shooting astro photography is capturing as much light as possible, with settings that still maintain as much quality as possible in your images. Too high of an ISO and you may introduce too much noise. Incorrect shutter speeds can under or overexpose your images. And an aperture that is too narrow will prevent enough light from entering the camera. Taking full control of the exposure triangle settings requires “Manual” mode so don’t be scared to use it!

And of course – shoot in RAW!

Stability is important – use a quality tripod

When the camera needs to be steady for longer exposures, it is very important to have a sturdy and stable tripod supporting your camera. Even the slightest wind can cause stars to be out of focus.

And if you plan to try techniques such as star trails or even timelapses of the Milky Way position changing as the Earth rotates, the camera position needs to be completely stable for long period of time.

Plan to shoot around “New Moon”

Planning to shoot around New Moon will limit the ambient light being cast across the foreground and other elements in the scene, but most importantly will reduce the amount of light haze being cast across the sky, therefore impacting on the ability to capture the stars at their best
There are times when ambient light is helpful – especially to help produce better quality foregrounds.

As you get more experience shooting you will learn the dynamic range capabilities of your camera, and post-processing techniques will also improve. But start with optimal conditions for a clear night sky to best capture the Milky Way core.

The “ISO” settings matter

Due to the very low light you will typically be shooting astro-photography in, a higher ISO setting is required to effectively turn up the “amplification” of the available light once it is collected by the sensor. A good starting point for ISO is 3200 and depending on the amount of ambient light available from either the moon or external light sources anywhere in your scene, adjusting from there once you get some test shots to see if your images are correctly exposed.

Manual focusing will be required

When you are focusing on the stars you will need to manually focus your lens and ensure you stay in manual focus while you are shooting. Typically most lenses will be focused correctly on the stars somewhere around the “Infinity” position.

To ensure your are focused correctly use the “magnification” modes on the rear screen of the camera to magnify what you are seeing. Most modern camera will allow you to zoom in up to 10x, allowing you to see stars on your screen. Try and find the brighter stars in the sky and make your focus adjutments from there using the focus ring on your lens.

Use the correct shutter speed

Shutter speeds for capturing pin point sharp stars are going to vary depending on the focal lengths you are shooting at. The wider the focal length, the slower your shutter speeds will be to maintain sharp stars with no movement.

With longer focal lengths (35mm+), the faster your shutter speeds need to be to ensure any movement and loss of sharpness as the Earth is rotating does not appear in your stars.

There is a formula which is very commonly used for calculating the maximum shutter speed for sharp stars for your focal length when shooting the Milky Way. It is –

Shutter Speed = 500 / (Crop Factor x Focal length)

So for a 16mm focal length on a full frame camera (crop factor of 1) the formula works like this with an answer of 31.25 seconds –
Shutter Speed = 500 / (1 x 16)

Replace any values with the correct crop factor below –

1x – Full frame cameras
1.5x – Nikon APS-C cameras
1.6x – Canon APS-C Camera
2x- Micro 4/3 cameras

Plan to shoot when there are no clouds in the sky!

Planning to shoot when the sky is clear is going to help maximise your chances of capturing great images! Optimal conditions are an early setting sun, New Moon, no light pollution and no clouds in the sky! Oh and it being dark. Of course…..

There are popular services like Clear Outside and which can help you plan whatever conditions you want to be in. If astro-photography is your aim, go out when the sky is clear!

Use an app like Photopills for planning

Planning to shoot in the right conditions can be challenging with astro photography. There are so many things that can impact on seeing the stars – a cloudy sky even when all other conditions line up being one of them.

Knowing when the Milky Way is going to be visible and at what angle in the sky it will allow you to plan to be in the right place at the right time. At different stages of the year, and throughout each night the Milky Way appears to stand more upright or lay across the sky. Apps like Photopills and Photographers Ephemeris can help with the finer details of where the Milky Way will be positioned and when optimal moon conditions are thoughout the year.

Photopills even has an “augmented reality” mode that when used correctly can show you the exact position of the Mliky Way at any given moment in time. You can stand at your location and see exactly where elements in the sky line up on what day and at the exact time!

Use a NiSi Natural Night Filter to remove light pollution

NiSi Natural Night Filters are designed to block unwanted wavelengths of light from artificial light sources such as city lights. A Natural Night Filter is best used for astro photogrraphy when there is distant city lights on the horizon, or when you are within the boundaries of a city and want to remove the haze caused by this common type of lighting situation.

A Natural Night Filter will cause less than a stop of light in reduction of light, and for most modern day full frame and mirrorless cameras this is easy to adjust for through ISO or a slightly longer shutter speed.

A good tip when using the Natural Night Filter is to shoot in Daylight White Balance mode to get the best result in terms of colour temperature.

Light paint the foreground

When it is completely dark is can be a challenge to get the foreground correctly exposed! A technique commonly used is to combine multiple exposures together to create a single image – one for the foreground typically taken at a lower ISO and longer shutter speed – and one or more for the sky.

Using an LED light panel that can throw out even light across the immediate foreground can introduce the right amount of light to capture the details in the foreground. We recommend LED light panel with adjustable luminance and white balance settings such as the Explorer Aura LED 915 and using it to throw light across your forground for just a second or so and adjust the technique from there once you see how your images are being exposed.

Leave a Comment

Item added to cart.
0 items - $0.00