Night Sky Photography

By Paso Robles Press · Thu Aug 01 2019

Hobby Combines Art and Science to Reveal Nature’s Hidden Beauty

I’m in the middle of nowhere. It’s a dark, moonless night — so dark I can’t see my own hands in front of my face. I’m in an unfamiliar place so I pull up Google Maps on my phone and try to use it to guide my way, along with my trusty flashlight. Wildlife rustles in the bushes around me. I hope it’s a squirrel or a rabbit and not a skunk or a mountain lion. I spot a great big old oak standing tall on the horizon, isolated from the other trees — a lone oak. I look up at the sky, searching for the faint, milky haze of stars that stretches from one horizon to the other and begin to make my way around the oak tree, looking for the perfect alignment, the one that matches the picture I’ve formed in my head.

I attached the camera to the tripod back at the car and have been hugging it in my arms since then as I chug along across the landscape, taking careful steps, terrified of tripping in the dark and shattering thousands of dollars worth of equipment. I find the right spot, adjust my tripod until the legs are in position and my camera is somewhat lined up with the composition I’m imagining — the big oak front and center, the Milky Way stretching out above. I use my flashlight to find the right camera settings, focus my lens to infinity, set my camera’s self-timer for two seconds and click the shutter button. Two seconds later the camera makes a slight clicking sound and a tiny red light comes on to indicate that the shutter is open. After waiting 15-20 seconds, the shutter softly clicks back into place and the freshly-taken image appears on my camera’s back display screen. In the photo, the hazy cloud across the night sky has transformed into a brilliant collection of shining stars, clustered in clumps around the galactic core, the bright center of our Milky Way Galaxy, and swimming amongst the multi-colored nebulas. By leaving the camera shutter open for an extended period of time, I’ve gathered enough light to see things that are not visible to the human eye. Through my camera I’ve unlocked one of the most spectacular sights that nature has to offer. 

Night sky photography can be challenging in many ways but it can also be a highly satisfying hobby and San Luis Obispo County provides plenty of dark skies and a bounty of natural beauty. Read on to learn more about the necessary equipment and techniques to take part in this hobby as well as some of the best places to give it a try. 

ESSENTIAL EQUIPMENT

Having the right equipment is extremely important for capturing images of the night sky and the Milky Way. You’ll need: 

• A STURDY TRIPOD: You’ll want to balance sturdiness with portability as capturing the night sky can often involve hiking with your tripod but sturdiness can also be essential when shooting in ocean waves, heavy winds, shifting sands and other challenging conditions. You’ll also want to find a tripod that allows you to easily place and hold the camera in a vertical position. In order to capture the full scale of the galactic core along with some foreground landscape elements, a vertical position is usually necessary. 
• A FULL-FRAME CAMERA: A digital camera with a full-frame sensor — meaning that the camera’s digital sensor is the same size as a frame of 35-millimeter film — is necessary for capturing clean images of the night sky. Cropped frame sensors — sensors that are typically half the size of a frame of 35-millimeter film — tend to introduce too much digital noise into long exposure photos. Digital noise, a phenomenon similar to film grain, causes random pixels to blow out and leave unpleasant stains and pixelation in photos taken with a long exposure or a high ISO setting. Most ‘prosumer’ cameras, including the popular Canon Rebel T series, use cropped frame sensors that will most likely give you undesirable results when attempting to shoot the night sky. Instead, look for full-frame sensors such as those found in Canon’s professional 5D and 6D series cameras. 
• A WIDE-APERTURE LENS: A wide-aperture lens — preferably one with an F-stop of 2.0 or lower — will help your camera’s sensor gather as much light as possible while keeping your ISO setting as low as possible in order to avoid introducing digital noise.
• A FLASHLIGHT/HEADLAMP: A good flashlight and/or headlamp is indispensable, not only for finding your way around and changing your camera settings, but also for light painting, the process of using a light source to light foreground objects or moving a light through the frame to leave behind streaks of color. Flashlights that allow you to adjust the intensity and/or color are ideal. 
• SOFTWARE: Shooting in the RAW format rather than J-PEG (the default setting on most cameras) will provide much more flexibility in the final image, will allow you to capture a wider dynamic range of light and produce a final image with less noise. In order to process RAW image files, you’ll need either Adobe Lightroom or the Camera Raw plugin for Adobe Photoshop. Adobe Lightroom provides a robust array of tools and adjustment bars along with a cataloging system to help you keep your photos organized. Camera Raw is a stripped down version that omits some tools and leaves the cataloging system out altogether. 

THE RIGHT PLACE AT THE RIGHT TIME

The location and timing are two of the most important factors in creating stunning night time photos. Unlike other types of photography, taking photos of the Milky Way is only possible during certain times of year, during certain parts of the lunar cycle, during certain times of night, in certain locations and only if the weather cooperates. If you’re attempting to use the ocean as foreground you need to factor in tides as well — throw in two jobs and a family to take care of and I’m lucky to get in a handful of shoots per year. 

The core of the Milky Way Galaxy (the most interesting part of the night sky) does not rise above the horizon during the winter months. During early spring it will only be visible in the pre-dawn hours and in late autumn it rises and sets well before midnight, so the summer months tend to provide the best photographic opportunities. 

Getting the best shots of the galactic core also requires shooting when the sky is moonless or when there is only a new moon or possibly a crescent moon. The light of the first quarter or full moon will blow out the sky and drastically reduce the visibility of the Milky Way. 

Finding the right place is also important. You’ll want to find someplace away from the lights of towns and cities, headlights and any bright, external house lights but also a place that has interesting or beautiful landscape and foreground elements. For more on where to shoot, see below.

PUSHING ALL THE RIGHT BUTTONS

Getting your camera settings correct is another one of the most vital aspects of capturing night sky photos. You can use the following as a good jumping off point and adjust from there based on the amount of available light:

• SHUTTER SPEED: You want to set your shutter to stay open for as long as possible in order to gather as much light as possible but if you leave it open for too long, the movement of the stars in the sky will start to show as a slight trail behind each pinpoint, mucking up the image and making it appear slightly blurry or unsharp. Using a shutter speed of 15 or 20 second will provide good results at most focal lengths. Anything beyond the 30 second mark will almost definitely cause star trails to show.
• APERTURE: Your camera’s aperture should be set for the widest possible setting (the lowest F-stop number) in order to allow as much light as possible to reach your camera’s sensor. Shooting with such a wide aperture in most settings would cause focusing the camera to become very difficult because of the shallow depth of field but when shooting the night sky you should set your lens to focus at infinity (marked on most lenses) to bring the stars into sharp focus so the shallow depth of field doesn’t matter. You may also opt to shoot one photo at infinity to get the stars sharp and then take a second shot using a flashlight to focus on a foreground object before blending the two images together in a process called “focus stacking.” 
• ISO: Your camera’s ISO setting controls the sensitivity of your camera’s digital sensor. Set your ISO too low and the sensor won’t record enough light for a proper exposure, set it too high and you’ll end up with digital noise. On most modern digital full-frame cameras digital noise is manageable at anything under 5-6,000 ISO. I usually use 2000 ISO as by starting point and adjust from there. 
• DRIVE: Although you can opt to use a fancy remote shutter trigger to avoid moving the camera when opening the shutter and causing your image to blur but using the built-in two-second timer works just as well. 
• FOCUS: Make sure to set your lenses focus to the infinity mark. Most lenses have a mark for infinity focus, which you should see when you turn the focus ring all the way to the left. After taking a test shot, you can use your camera’s display screen to zoom in on a star and make sure it’s completely in focus.

BEST PLACES TO SHOOT IN SLO COUNTY

If you can manage to stay away from light pollution, many of the beaches along the Central Coast can provide a nice foreground for night sky photos but more often than not, sea mist and cloud cover can be an issue as the marine layer moves in. On a clear day though, the rocky shoreline and cliffs of Shell Beach are a favorite with local photographers. One of the darkest spots along the local coastline, Montaña de Oro State Park is another good choice. 

For the darkest skies in the county, head north. We may not have the beaches but the North County has spectacular dark skies in many places and the skies are almost always cloud-free during the summer months. 

As cities go, Atascadero emits relatively little light pollution and I’ve managed to capture some decent night sky photos inside the city limits. Notable dark spots in Atascadero include Pine Mountain/Stadium Park, the Jim Green Trail and the wilderness around the Salinas River. Although it is too bright at the city center, there are also many areas on the outskirts of Paso Robles that are suitably dark. 

For the absolute darkest skies in the county, head out east of Atascadero on Highway 41 or east of Santa Margarita on Highway 58. The northeastern part of SLO County is so dark that you can see much of the Milky Way with the naked eye. Particular favorite spots of mine include the vineyards at Pomar Junction, Shell Creek Road (off Highway 58 east), Chapel Hill (near Shandon), and in the vineyards southwest of Paso Robles off Highway 46 West and Vineyard Drive. 

To me, night sky photography is the perfect hobby. The equipment may be expensive to purchase but once that’s out of the way I can go out and shoot any time I feel like it and it doesn’t cost anything. There’s a slower pace than most types of photography with each exposure taking 15-20 seconds, allowing me to take my time and think through each composition. I get lost in the work and it becomes a sort of meditation for me — a meditation that perfectly balances the artistic and scientific sides of my mind. If you lean toward the introspective side of the personality spectrum, enjoy learning technical skills and have an artistic eye, you may enjoy night sky photography as well.