June 22, 2017
Astrophotography Star Search with Sara Wager
On a mission to illuminate objects invisible to the naked eye, UK based Sara Wager has spent countless hours photographing the infinite expanse of space. Through a combination of passion, technical expertise, and incredible patience, Wager manages to successfully document her deep space subjects, bringing celestial bodies into plain view. We caught up with Wager to gain insight into the painstaking process of capturing the cosmic.
What sparked your interest in photographing space?
I used to have an interest in daytime photography and had a couple of full frame cameras and some nice lenses. I saw some deep sky images and thought that looked like a simple enough thing to photograph. So when we moved to Spain from the UK, I decided to give it a go. How difficult could it be? 😉
What do you look for when capturing an image?
For inspiration, I spend a lot of time looking on the net and in books. I’ve got a mountain of Sky Atlases and all sorts of other books that help me identify where targets may be. For example, targets in the summer are not available in the winter, so what you can photograph is dependent on the position of the Earth and its respective seasons.
I generally have an overall image in mind when I start out as I now have a pretty good idea how things will turn out.
What kinds of formations attract you the most?
I love nebulas. Using different filters I can get an array of colours in the image. Nebulas are also made of fascinating shapes and some are huge! There’s never a dull nebula!
Did you get a telescope specifically for photography or just as a hobby?
I got all the equipment specifically for astrophotography. I’ve always been an image capturer and have almost never looked through the scope without a camera. It sounds odd but the telescope is actually one of the less important parts of the complete setup. THE most important thing is the mount. If you don’t have a good solid base with which to start from then you can’t get the long exposures that you need.
How do you capture these images? What is the technical aspect?
Technically this area is HUGE.
MOUNT & GUIDE
I have a mount and guide camera running software that will keep a star to within one pixel all night. The mount works alongside a separate guiding camera. The guide camera takes an image every 3 seconds so it keeps the star in static. The mount is built so it can move in both axes allowing for the earth’s rotation while keeping the target rotated as well. It basically works with the natural movement of the sky.
CAMERA & FILTERS
I shoot with a specific astronomy camera called a charge-coupled device (CCD) monochromatic camera. It looks nothing like a DSLR and the chip is smaller than a DSLR as well. The CCD camera is very sensitive due to the lack of the Bayer matrix filter that all colour cameras have. This means that every single photon of light is captured by the sensor and converted to data. The sensor gets cooled to up to 40 degrees below the ambient temperature as a way to combat noise in the image.
I also use filters in order to collect data. Each filter catches a specific wavelength of light. Once captured, these mono images are combined or stacked in Photoshop to create a composite colour image.
Each exposure lasts for 30 minutes. Yes, the shutter really is open for 30 minutes! And I can often collect 40 hours or more of exposures on a single target for one photo. Specialized software allows me to return to the same spot night after night, year after year to capture my images.
Processing one image can take upwards of 10 hours and will regularly take me many days. Once it has sat in my PC for 3 days without any tweaks then I know I am happy to publish it!
It’s a really long, technical process. There’s much more info in my Youtube video and there’s also a lot of information on my website.
Anything else spacey coming up for you?
I’ve recently returned from a Central European DeepSky Imaging conference in Austria where I was the first female speaker ever. I also write articles for a UK Astronomy magazine, so I’m always on the lookout for new ideas! I’m collaborating on a book which will be published next year.
I just keep my eye on the weather and can usually be found with my scopes pointing skywards on a clear night. I try to make my images interesting and colourful and hope that I can show people the joys of the universe!
Sara Wager is a UK expat photographer who developed a love for astrophotography and all its hardships when she moved to Spain. Most nights she can be found in her observatory, pouring over her next target or moaning about the weather when the clouds block her view. Sara is passionate about astrophotography and her self-imposed responsibility to help guide other astrophotographers. See more of Sara’s work on Stocksy >>