How to Reduce Noise on Long Exposures and High ISO Speeds

November 29, 2011 · 0 comments

in Equipment,Interiors,Resources,Tutorials

What is Noise?

Noise is the digital equivalent of film grain. It even looks like grain, except a far more ugly version! Noise results from a variety of sources such sampling errors in pixels, temperature-induced “dark currents” in sensor elements, and signal amplification circuits.

Just as high-speed film yields more grain than low-speed film, digital photos taken at high ISO settings show far more noise than photos taken at low ISO settings.

If you have a Canon 5D Mark II, the Noise Reduction settings are not default, so I highly recommend spending a few minutes setting your camera as explained below…

Long Exposure Noise Reduction

Under the Custom Function Menu, select C.Fn II: Image

Under C.Fn II 1, you can set Long Exposure Noise Reduction to Off, Auto, or On.

By selecting On, Noise Reduction is performed on all exposures of 1 second or longer.

After the photograph is taken, the noise reduction will take the same amount of time as the exposure, ie: After a 30 second exposure, the Noise Reduction will take an additional 30 seconds.

Tram in Den Hague – Shot with a Long Exposure

High ISO Noise Reduction

Under the Custom Function Menu, select C.Fn II: Image

Under C.Fn II 2, you can set High ISO speed Noise Reduction to Standard, Low, Strong or Disable.

Selecting Strong will reduce noise generated in the image.

Although noise reduction is applied at all ISO speeds, it is most effective at high ISO speeds.

At low ISO speeds the noise in the shadow areas is further reduced.

Note that if you select Strong, the maximum burst for continuous shooting will decrease greatly.

Super Sport Studio – Shot with a High ISO

Noise Reduction Software

If you are still dissatisfied with the amount of Noise in your images, try Noise Ninja. You can create a custom profile for your camera to remove unwanted noise while doing the least amount of damage to your images.

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