Long exposures, at night for star trails, or simply because of low light, once meant simply the bulb setting (or T) on the shutter, and some calculations (guesstimations) of reciprocity failure exposure compensation, multiple tries and faith. Absolutely beautiful work could be done, but it took practice and patience–of course, most photography does.

Nowadays things are different, but challenges remain. Silicon builds up noise with long exposures, with heat being one of the problems. In astrophotography this is battled back by cooling circuits on the cameras, or even liquid nitrogen for the big guys.

Many of our cameras now have long exposure noise reduction modes which very cleverly takes a photograph subsequent to your exposure, of the same length, with the shutter closed, thus producing a noise map of the sensor. That so-called dark current image is then subtracted from the image. These features are well worth using.

Canon 1Ds Mark III Long Exposure Noise Reduction Menu

Additionally, lower resolution dSLR cameras tend to be more sensitive as their pixel wells are larger, therefore have more silicon per pixel to gather photons. I've seen the difference between a 6 megapixel dSLR and a 22 megapixel camera, at the same ISO, aperture and time, reveal the Milky Way in the lower res photo, and barely see stars in the other.

Focusing can also be a real problem on low light photography. A green laser can sometimes help on stationary objects by providing a bright pinpoint of light to focus on when pointed at your subject.

Star Trails and Crosses (combined from 3 different exposures). Mission San Antonio. 2011.
Total of 13 minute exposure. Canon 1Ds Mark III.

Balanced Rock and Star Trails. Arches National Park. 2009.
6 minute exposure. Canon 1Ds Mark III.

Night Sky and Laser. Death Valley National Park. 2009.
6 minute exposure. Canon 1Ds Mark III

Additional Tutorials

More Tutorials, Technical discussions and Essays are linked from the Techniques Button on our Home page.

Techniques Page

Photography Workshops

Interested in learning more? Perhaps one of our digital photography classes would be of help? We take the imparting of information and the empowerment of our students quite seriously. The digital age has considerably enhanced our ability to teach, and we believe your ability to capture what you see. This program is designed to help you benefit from both of these advances. We hope you can join us on a workshop.

Next Workshops:

Photography Critique
May 26, 2011

Photoshop Straight and True
June 11-12, 2011

San Francisco Digitally
July 16-17, 2011

Maine Media Workshops

• Vision and Craft: Perfecting the Photographic Image: June 19-24
• Printing Photographic Beauty: June 26-July 1

RAW to Print: Summer Digital Bootcamp
July 11-15, 2011

The Fine Art Print
July 18-22, 2011

Mono Lake and the Eastern Sierra
October 8-11, 2011

Guangxi China
November 7-19, 2011

Death Valley in Winter
January 2012

Tanzania Africa February 2012
date to be determined, please email

Galapagos March 2012
date to be determined, please email

For a full list of current workshops, click here.

Workshop Testimonials