The 500 Rule for Night Photography

[Frederic]

The 500 rule is a well known rule amongst photographers to have a guideline when it comes to setting the shutter speed according to your focal length.

Basically it means to avoid blurry shots, the longest shutter speed you can use is equal to 500 divided by your focal length.

For example, if your focal length is 20mm, the 500 rule says that you can use a shutter speed of 500/20, or 25 seconds. Here’s a quick chart of the longest shutter speeds you can use at night for a given lens. (The numbers below are full-frame equivalents. If you have, for example, an 18mm lens on a 1.5x crop-sensor camera, you’ll need to look at 28mm on this chart):

-11mm: 45.5 seconds

-12mm: 41.7 seconds

-14mm: 35.7 seconds

-16mm: 31.3 seconds

-18mm: 27.8 seconds

-20mm: 25 seconds

-24mm: 20.8 seconds

-28mm: 17.9 seconds

-35mm: 14.3 seconds

-50mm: 10 seconds

-85mm: 5.9 seconds

The numbers keep changing because new cameras have more and more pixels, which means that they can detect smaller and smaller star movements. The chart above is a good guide, but you’ll want to test your own camera to confirm that there isn’t too much movement, particularly if you have a recent camera with an extremely high megapixel count (more than 36).

night-sky-cheat-sheet-new.pdf

[Thomas Varghese]

1 hour ago, Frederic said:

The 500 rule is a well known rule amongst photographers to have a guideline when it comes to setting the shutter speed according to your focal length.

Basically it means to avoid blurry shots, the longest shutter speed you can use is equal to 500 divided by your focal length.

For example, if your focal length is 20mm, the 500 rule says that you can use a shutter speed of 500/20, or 25 seconds. Here’s a quick chart of the longest shutter speeds you can use at night for a given lens. (The numbers below are full-frame equivalents. If you have, for example, an 18mm lens on a 1.5x crop-sensor camera, you’ll need to look at 28mm on this chart):

-11mm: 45.5 seconds

-12mm: 41.7 seconds

-14mm: 35.7 seconds

-16mm: 31.3 seconds

-18mm: 27.8 seconds

-20mm: 25 seconds

-24mm: 20.8 seconds

-28mm: 17.9 seconds

-35mm: 14.3 seconds

-50mm: 10 seconds

-85mm: 5.9 seconds

The numbers keep changing because new cameras have more and more pixels, which means that they can detect smaller and smaller star movements. The chart above is a good guide, but you’ll want to test your own camera to confirm that there isn’t too much movement, particularly if you have a recent camera with an extremely high megapixel count (more than 36).

Are these seconds to be considered just plainly or 1/the time mentioned? None of these speeds mentioned can be achieved handheld and you sure need a firm support to anchor the camera. If you are firmly anchoring the camera I believe you can shoot at any speeds. @Frederic please clarify

[Frederic]

6 minutes ago, Thomas Varghese said:

Are these seconds to be considered just plainly or 1/the time mentioned? None of these speeds mentioned can be achieved handheld and you sure need a firm support to anchor the camera. If you are firmly anchoring the camera I believe you can shoot at any speeds. @Frederic please clarify

This is specifically related to astrophotography where you would need to use a tripod or stand, and these are just guidelines of course. They are actual seconds. For example:

- Max shutter speed for a 50mm lens is 500 divided by 50 = 10 seconds. 

[Frederic]

https://www.photopills.com/calculators/spotstars

 

[Thomas Varghese]

2 minutes ago, Frederic said:

https://www.photopills.com/calculators/spotstars

 

Its very advanced calculation and I think only to be used by astro photographers for which you need to have very deep knowledge about modifying the camera, the lenses to be used, the declination of stars etc. I am very happy with the present set up which keeps me wondering which type of photography to be pursued with the equipment I have. After coming to know about anamorphic lenses and how the movie stars were portrayed in movies in larger than life sizes I want to try them for my portraits