What is Astrophotography

Have you ever wondered if the night-sky could be captured on camera? Did you think that only the Hubble space telescope could accomplish such a feat? Introduce astrophotography.

Astrophotography: What is it

Also known as astronomical, celestial or night-sky photography, astrophotography is a specialized form of photography which is not widely known and combines astronomy, photography and nature. According to author Bert Krages from his book Heavenly Bodies: the Photographer’s Guide to Astrophotography, “astrophotography is one of the most demanding applications of optics”. (Amherst Media).

Why is it pursued

Astrophotography is unique in that you are attempting to expose in extreme low-light of celestial objects that are billions of miles or light years away. It is very challenging yet rewarding to the pursuer and may also open the door to scientific discoveries. Many astroimagers will tell you that capturing a deep-space subject, such as a galaxy or nebulae, light years away hooks you forever. Maybe most importantly is the astroimager’s connection to the earth and our place in the cosmos.

Who pursues it

Astrophotography is most-often pursued by individuals who have a special connection to science and art. Specifically, astronomy and photography. Astroimagers may be from any walk of life but many have made the jump into this “niche” from roots in amateur astronomy. Some are photographers who strive for the extremes while others have a general love for nature.

According to professor and astroimager David Malin, “Astrophotography attracts an interesting variety of people. Many are experienced camera users looking for new and unusual image-making opportunities. Other potential recruits are already fascinated by the night sky, astronomy and space”. (Forward by David Malin, p.4, Astrophotography: An introduction to film and digital imaging, Arnold, H. J. P., Firefly Publishing).

Where is it done?There is a saying in real estate which also applies to night-sky photography: Location, Location, Location. Astrophotography is best accomplished in dark site rural areas where there is very little light intrusion. The darker the skies, the better the “seeing” is and the more successful your photo shoot.

How is it accomplished and when

The most basic level of astrophotography, known as camera-on-tripod, can be pursued using only basic equipment as follows:

35mm SLR camera, film or digital, with a “Bulb” or “B” setting for long-exposures.
For optics, a standard lens in the 50mm range with a f2.8 setting as a starter.
A cable release (film) or remote shutter release (digital)

A light weight but sturdy tripod

Basic astroimaging is a simple approach. Just aim the field of view on your target, set your lens to infinity and check focus, lock open the shutter for a specified time, close it and then on to the photo lab or your LCD screen.

Astrophotography is most often done during the dark hours of the night, mainly later at night and during the early morning hours.

The advantages to imaging later at night are:

less light pollution
steadier atmosphere
less air traffic
fewer interruptions

The disadvantages:

sleep deprivation
colder temperatures in colder regions
dew
the darkness at night

One of the keys to becoming a successful astroimager is frequent hands-on practice in the field. Taking good notes, burning lots of film or memory cards is a recipe for success!

Astroimaging can be done very successfully with just a modest budget. With some basic equipment, a dark-sky site and a little bit of patience, sacrifice and diligience, you too, can become an astrophotographer. Hopefully this article will have ignited a spark that may start you on a life-long journey to the stars!

Introduction to Basic Night-Sky Photography

Otherwise known as camera-on-tripod astroimaging, this basic method provides the foundation you will need to get a feel for what astrophotography is and challenge you to work your way up the learning curve.

Where to Start

Many astroimagers find that entering the shallow end of the pool with the basic level provides them with enough challenges and rewards without moving on to higher steps. It all depends on your interests, time, budget and motivations. A 35mm SLR camera, film or digital, a cable release (film camera) or remote shutter release (digital camera) and a lightweight but sturdy tripod is all that is needed. Choosing your recording medium comes next. 35mm film or digital sensor?

Astroimaging With Film

If you plan on using film, obtain a fully-manual and mechanical 35mm SLR with the ability to set to Bulb. This will allow you to do long-exposures, often required in astroimaging, without concern for depleted batteries. Author H.J.P. Arnold, a well-known professional photographer and science writer, says of selecting a proper camera, “Cameras made by the likes of Nikon, Canon, Olympus, Minolta, Practika, Contax and Leica come immediately to mind.” Furthermore, Arnold says, “Classic examples of such cameras will be readily recognized by older, experienced photographers – Nikon FMs, Olympus OM-1s, Canon F1s, SRT-101s from Minolta and not to forget the Pentak K-1000.” Astrophotography: An Introduction to Film and Digital Imaging, Firefly Books Ltd., 2003, p.29.

35mm color print film from Fuji or Kodak in the ISO 25-400 range is good. Print film can be adjusted at the lab since its exposure latitude is more forgiving then slide film.

35mm color slide film is usually a favorite among astrophotographers since they produce vibrant images and are easier to catalog and use for presentations. The main disadvantage to slide film is its exposure latitude. With slides, “what you see is what you get’ and the celestial imager must be more accurate with exposure settings.

Here is a list of items to remember when pursuing digital astroimaging:

Digital 35mm SLR (6 megapixels or more)
A light-weight but sturdy tripod with ball head or 3-way pan head
Standard to wide-angle lenses with fast optics
Remote shutter release
Memory card with enough memory and spare
Fully-charged battery and spare
Electrical power supply (optional)
Lens cleaning cloth or brush

What is a DSLR

Author Michael A. Covington in his new book says, “A DSLR is a digital camera that is built like a film SLR (single-lens reflex) and has the ability to interchange lenses. You can attach a DSLR to anything that will form an image, whether it’s a modern camera lens, an old lens you have adapted, or a telescope, microscope, or other instrument.” Digital SLR Astrophotography, p.3, Cambridge University Press, 2007.

Some of the best digital SLR’s for astroimaging are manufactured by Canon and Nikon, although other camera makers such as Leica, Sony, Pentax and Olympus also provide good choices. You can buy the best digital or film camera but without a proper support system your imaging will be fruitless. An astroimager may be somewhat successful with short exposures of a bright object such as the moon while handholding the camera. The moon is big and bright providing enough light for your meter and with an image-stablizing lens (IS) attached, you might get a “keeper.”

The Camera and Tripod – A Crucial Connection

Tripods are a “must” for astrophotography in which long exposures from 1 sec to as much as 6 hours are routinely done. The tripod must be lightweight so that it is easy to carry, assemble and deassemble in the field but also must be sturdy to hold the weight of the camera and to prevent induced vibrations caused by nature’s elements such as wind.

Also of importance is using high quality glass and fast optics. This is especially true of higher quality DSLRs. Using a 12-, 15- or 22-megapixel camera with a $130 lens defeats the purpose of obtaining high quality images. Try to purchase fixed focal-length lenses with fast optics in the f2-f2.8 range. If not, zoom lenses today are also good but be sure to buy “fast glass”.