How to Photograph the Milky Way Bow

In this article, we will take a closer look at how to photograph the Milky Way bow. I wrote this guide from the point of view of a person who has largely taught himself. During the last four years, I have also had the invaluable help of a fellow night photographer. I made all the mistakes and then tried a lot of corrections while I learned and worked to inspire others to try it out, too. I will admit to liking my night photos when they look like they are taken at night, apart from moonlight shots which may sometimes turn night to day.

Background and History

I grew up on the pacific island of Tarawa in the middle of the Pacific Ocean in the 1960s. We had no pollution – no big cities. Just coconut trees and inky black skies at night, with the Milky Way sitting above the ocean. I was the oldest son, so I got to sit with the stopwatch and count for my father as he tried to capture the stars and Milky Way on film. Sadly, he never truly did. Only after the introduction of digital could I see why: There are far too many things to go wrong on film. The following tutorial is all taken from my experience using a Nikon D600 and Samyang 14mm f/2.8. This is a full frame camera and lens, but all the techniques below can easily be converted to DX and crop-sensor cameras.

Basic Camera Settings

Below are the basic camera settings I use for photographing the Milky Way bows:

• Camera Mode: Manual
• White Balance: 4000-4200
• ISO: 3200-5000
• File Format: 14 bit RAW + JPEG (since some things I want to do don’t use RAW)
• Shutter Release: 2 second timer. That way, you are not touching the camera at all, apart from start of the timer. Alternatively, use a remote
• Shutter Speed for Single Shots: 20 seconds
• Shutter speed for Bows: 25 seconds (more on this later); the time does not change, regardless of moonlight or darkness levels
• Aperture: f/2.8 on a dark night, or the widest aperture on your lens. In moonlight, f/4-5.6
• Long Exposure Noise Reduction: On
• VR / IS: Off, if your lens has it

Another valuable tip is to move the focus from the shutter release to a dedicated button (such as AF-On). That way, the shutter release only captures the photo and does not re-focus, so that you don’t end up with a ruined image. Or, switch to manual focus only.

Having done all this, my first shot is to test and make sure that everything is perfect. For example, are the corners of the shot pinpoints or trails? This is something you will need to correct out in the dark. Sometimes, a piece of paper with your settings written on it may be a good idea to use. Especially when beginning astrophotography, the night environment is perfect for making mistakes that are easy to avoid during the day. A list of exposure settings and other menu settings is crucial to remember, and, if you forget, you can easily refer to the paper – you do have a torch! All this becomes second nature the more you learn and practice.

Another good tip is to use the “My Menu” setting (if your camera has one) to store all the important settings you would use at night. Another option is to store these settings in a dedicated camera mode such as U1 / U2 or menu banks.

Focusing

This is one of the hardest things to do at night. There is an article on Photography Life about focusing at night, but I will cover a bit of information here as well.

I advise you to use “live view” – find a bright star, magnify the LCD, and focus manually, as there is no auto focus in the black of the night. Or, the lazy way I use is to focus on the clouds or some other object at infinity during the day. Once it is perfect in live view, tape the focus ring of the lens so that it stays in the same position. The advantage of the tape is that it prevents you from moving the lens focus accidentally, ruining your night sky images. This is also a good time to turn off autofocus.

Rules and Some Math

My first two tries showed a lot of promise, so I thought I would look into this more, but I needed more light so it was a case of how much time could I hold the shutter open for. The Internet showed me two rules for the ideal time: the “600” and “500 rule.”

Basically, you divide this number by your focal length, which yields the time in seconds that your maximum shutter speed can be, while avoiding star trails in  the image. For example, for a 14mm lens, you would get a 42 second exposure when using the 600 rule (600 divided by 14mm = 42).

However, I found that the stars would trail all the time when shooting for this long. Things were better with the 500 rule, which says that I should be OK at 35 seconds. Still, I found my stars where not pinpoints at the edge of the frame, and I was back to the drawing board to find the right time. I went down to 28sec, 26sec, 25 sec and finally down to 23 sec, where I could see no trailing at all. So by reverse engineering, I ended up with 333 as the right figure. As you can see, it is a long way from 500 or 600!

So if I apply the “333 Rule”, I would get 23.78 seconds with the same 14mm lens. This works fine, but I cannot change the internal shutter speed on a Nikon to numbers between 20 and 25, unless I use a remote shutter release. The solution is just to pick one or the other; you should not see too much trailing at 25 seconds, but you can go down to 20 seconds if you want to be safe.

If you have a cropped sensor camera such as the Nikon D7100, use the following math: 333 divided by 1.5 (crop factor) = 222, so this becomes a “222 Rule” for 1.5x cropped sensor cameras. Next, divide the focal length by this number to obtain the right shutter speed. For example, for an 18mm lens, 222 divided by 18 would result in a 12.3 second exposure time.

For APS-C / DX shooters, the Samyang 10mm f/2.8 ED AS NCS CS would be the right choice, equivalent to a 15mm lens on full-frame cameras.

For any other camera system with a different crop factor, use the same base numbers as a reference and take into account the crop factor. For example, for Canon cameras with a 1.6x crop factor and an 18mm lens, the numbers would look like this:

• 333 divided by 1.6x (crop factor) = the “208 rule”
• 208 divided by 18mm = 11.5 seconds

Use these settings as a start, but always test and check your first shot to see if you need to adjust differently. All lens / camera combinations are different, so check by enlarging the shot on the back of the camera to see the full detail. It also depends upon the area of the sky which you photograph, since the stars move more quickly across the sky when they are closer to the celestial equator (farther away from the North Star for readers in the Northern Hemisphere). So, all of these figures are estimates, but they should get you on the right track.

Tripod and Tripod Head

On this very site there is an excellent article on choosing a tripod. Over time, you will find that the best tripods are worth the money, as they will serve you for many years to come. Consider a solid tripod to be an important investment, so buy it once and buy the right one from the start. My own tripod has no center column, so it is rock steady. And, at 6’3″, my viewfinder is at my eye level. I use a ballhead that is calibrated on the bottom, so that I can move the head around in correct movements of degrees to take panoramic images.

My tripod has a few little extras. I have a small bubble spirit level on the top of each leg, so I can easily see the angle of the tripod. Using a single spirit level is not as accurate, once you come to stitch a group of 13 shots to make a full 360-degree panorama or 16 shots of a double row Bow.

I use an “L-bracket” on the camera, so changing from vertical to horizontal orientation is as easy as detaching the camera and flipping it, with the head staying unchanged. Another worthwhile investment.

I use the “Virtual Horizon” feature of the camera to level the camera up to the level head of the tripod, and I always have a little drag on the tripod head so the camera cannot move on its own under its own weight. You do not want any mistakes to end up with hard-to-fix issues once you load up your images on a big screen.

Planning

I use four tools to help plan where I go, when, what direction to shoot, and, most importantly, what I can expect to see:

• Stellarium – this will show you where to find the Milky Way, and it is very easy to use.
• Moon Phase Plus – or a similar app to see the state of the moon.
• Google Earth – to see the site before you get there (though I always get there early to look around; things change!)
• Night Lights – to see how dark it is where you are planning to take pictures. I live in Perth, Western Australia, so I am blessed with very black skies and so few cities around.

Don’t forget to get a good app to check on weather, especially any cloud movements in the area.

The Early Shots

My own experience started when I purchased a Nikon D600 and a Samyang 14mm f/2.8 AE. My first ever shot was on a moonlit night and the fire we had that day:

I counted in my head as I held the shutter open with a remote and did not even think in those days to use a proper timer. It is very confusing out in the dark and there is a lot to remember, so the first few nights where a real trial. My next night out, I chose a very dark night without a moon:

Never give up if your shot may not be quite what you wanted – I asked my fellow photographer to stand still while he stood to the side of his camera and set it. He turned on his head lamp, adjusted the Nikon D800E and 14-24mm, then moved back to take the shot. Here is that shot hands, camera, tripod and body as one – out under the stars, the magic of long exposure.

The Milky Way Bow

The next step is to be able to make a Milky Way Bow out of your shots. I must confess here – I had no idea how to go about it. I first took them as horizontals, as it took less time and easier to stitch. Wrong! It was a harder and a wrong way to take the photos. You are better off capturing photos in vertical format, as you also get the most number of stars in the shot and information when it is all stitched together.

I had my Milky Way Bow shots 3 months before I could get a good program to stitch them. Most programs would stitch well for day shots, but fail for night shots. I tried a number of different tools including Adobe Photoshop, Lightroom, Arcsoft Panorama Maker, Microsoft Ice and Hugin. I had all sorts of problems with them all in their own ways. For example, compare the two shots below. The first one was stitched in Photoshop – the ground is flat and you see double stars at the joins, but not the way you see the stars in the sky.

My second night partner told me try PTGui – it turned out to be the best for astrophotography. It is not free, but the results speak for themselves:

You have to set control points and you have far more control over the end result. You can move the whole thing about and use masking tools as well (the best way to get rid of airplanes).

Setup

When I do a Milky Way Bow or a 360 degree panorama, I take the time to make sure that the tripod head is level on all three of my extra bubble levels. Then it is a matter of making sure that the Virtual Horizon in camera is also good. I then start from a set point on the tripod head with my 14mm lens and move the setup in 30 degree increments for each vertical shot before or after the Milky Way Bow. This is where the slight trailing stars at 25 seconds can be eliminated in the stitching process. I have even done a two-row stitch of the Milky Way:

Sometimes, you have to be flexible. When I got to the site, what I thought was my 14mm was in fact my 50mm f/1.8 lens, and my 16-35mm f/4 was also in the bag. I had never used this lens for astrophotography, but a three-hour drive was a long way to go to get it. So another tip is to always double check and make sure you have everything in your bag before you leave! The Nikon 16-35mm f/4G VR shone after I went through the finished photo set from that lens and luckily, I kept a spare tape on the top of my tripod leg, just in case.

Summary

I hope that in some way this article has taken the mystique out of night photography for you. I am just an average Joe, not a pro photographer, so this is the information and the tips I can share with you based on what I have learned so far. It is my hope that if you get a chance, you will get the camera out and give it a try. There is nothing like the very first photo on the back of your camera at night!

When my fellow night shooter asked me why I wanted to do astrophotography, my answer was “test the brain, patience and the resolve.” It always pays to plan ahead, so you have some things to work on. If you never plan, you will never go – as simple as that. Some of the shots from this article are from 4 hour drives out of the metro area, so keep in mind that you have to plan and you must think well ahead of time. If you follow a few simple principles pointed out in this article, I am sure you can get some great images at night!

I would also like to point out that none of these shots have been altered in post-processing software other than some global edits. I did not enhance the Milky Way in Photoshop like many others do, because as a former film shooter, I prefer this natural look. I have printed large metal 1200cm x 750cm pictures for my home, so that I can remember why I own a camera and enjoy life.

Hope to catch you out under the stars, enjoying the night sky!

This guest post was contributed by Steve Paxton.