Astro photography rule of 600

The rule of 600 for Astro photography

For those that like to take star pictures and are trying not to have star trails the rule of 600 is something that you need to know for this and your other Astro Photography.

The rule is as follows, you take the millimeters of the lens that you are shooting and divide it into 600, this gives you the maximum number of seconds that you can expose the shot for before you will see star trails.

One note: you need the 35mm equivalent lens size.

So how does it work?

Full Frame Sensors
On full frame cameras (cameras with full frame sensors) you would do the following:

Lens – 50mm

600/50 = 12 So you could shoot at a shutter speed up to 12 seconds before you will see lens movement.


APS Sized Sensors
On a camera that has an APS size sensor with a 1.4 conversion ratio you would do the following

Lens – 50mm

50 x 1.4 = 70

600/70 = 8.6 So you could shoot up to 8.6 seconds before you would see star trails

Who are we……….

Paterson Photography offers a variety of courses, workshops and adventures around Canada.  From our classes at our Lethbridge studio, (our one on one classes and  group classes), adventures, workshops and expeditions and more you will love learning your camera. Visit our web site, E-mail or call for more information.

Paterson Photography is the only custom photo printer in Lethbridge and area.  We offer prints from wallets to 44″x100″ on a variety of media.  No cheap, poor color poster prints – all our printing is done on archival media at the highest resolutions. We print for individuals, companies and groups that want quality prints.

Paterson Photography has operated in Lethbridge Alberta since 1985.  We are proud to offer wedding, graduations, personal portraits, commercial and industrial photography and more.

Please follow and like us:

1 thought on “Astro photography rule of 600”

  1. Your post, “Astro photography rule of 600 ended up being worthy of writing a comment on!

    Simply desired to mention u did a tremendous work.

    Many thanks -Mauricio

Leave a Comment