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Archive for the ‘Equipment’ Category

Most modern Nikon and Canon cameras have a neat but underutilized feature – in-camera multiple exposure.  This is a handy feature that has lots of uses, so here’s a quick primer.  I’ll cover how the function works and demonstrate a couple of common uses.  We’re going to look at two situations.  In this blog we’ll look at how to use the multiple exposure function to have a longer effective exposure without using ND filters.

One of my favorite techniques for photographing water is to use the multiple exposure function instead of a neutral density filter.   There are several situations where this applies.  The most common is you simply did not bring a neutral density filter and need a longer exposure.   You might also be in a situation where you want the effect of a longer exposure than can be used – such wanting a 20 second exposure without the curl of breaking waves, but the waves are breaking on a five second cycle.  Or you might not have a strong enough ND filter – such as using a Variable ND filter but trying to avoid unevenness that comes with maximum ND.

Here is an example.  The first image is a five second exposure of a coastal scene at sunset.  The image was made with a D800E and exposure settings of 5 seconds, f/16, and Lo 1.0 ISO.  The only way to lengthen the exposure was to raise aperture, and this would introduce a dark band in the image from the curl of the waves.   Note that there is a clear texture to the foam in the water.

Jedediah Smith Redwoods State Park / False Klamath Cove

5 seconds, f/16, ISO 50  – False Klamath Cove

The second image is the result of a 9 image in-camera multiple exposure with exactly the same settings for each image – 5 seconds, f/16, and ISO Lo 1.0.  This resulted in cumulative exposure of 45 seconds which creates a very soft, gauzy effect for the water and without any breaking waves.  In addition to the cumulative effect of the actual exposures, there was also time between exposures because each exposure was manually triggered.

Jedediah Smith Redwoods State Park / False Klamath Cove

9 frame in-camera multiple exposure  – each 5 sec, f/16, ISO 50 – False Klamath Cove

Setting up Multiple Exposures

The process for creating an in camera multiple exposure is very easy, but the first time through it may be confusing.  We’ll walk through the steps involved.  Keep in mind the camera menus may be a little different, but the ideas are consistent.

 

It’s better to use a cable release and a tripod for multiple exposures.  You can usually use Exposure Delay Mode instead of a cable release, but you may need to account for the time between frames.  Mirror Lock Up may be useful in some situations.

 

  1. Under the Shooting Menu – select Multiple Exposure
  2. Select the Multiple Exposure Mode and scroll right to see the menu options
  3. Select either a single Multiple Exposure or a series

Note: It’s usually better to select On (single photo) rather than On (series) because invariably you will forget that you had a series selected and will ruin some subsequent images by taking multiple exposures by mistake.

  1. Select the Number of Shots for your multiple exposure

The number of exposures possible varies by camera model.  The number you want to select depends on the desired effect.  Depending on the camera the options are usually 1-10 or 1-3.

  1. Set Auto Gain to On in order to average the exposures

Auto Gain simply averages the exposures together.  In the film days, you’d need to manually calculate the exposure times to account for the cumulative impact.  Digital cameras do the math for you, but you could turn off Auto Gain and make your own calculations for the weight of each exposure.

  1. Go to the Tools Menu and turn off Long Exposure Noise Reduction.

Long Exposure Noise Reduction adds to the time between images, so in most cases it’s better to turn it off.  This step is not required but usually makes a better image.

The settings for the Canon cameras are similar.  You would choose “Average” rather than Auto Gain On.  But the technique works in essentially the same manner and produces a single file in the camera.

If you are using multiple exposures instead of a ND filter, you can calculate the equivalent exposure based on the number of stops.  Two exposures is double the time or one stop, four exposures is two stops, and eight exposures is three stops.  Keep in mind these are rough estimates because in some cases there is an impact on the equivalent exposure from the time between images.

Now you are ready to create your multiple exposure image.  Simply trigger the shutter in the usual manner.  I usually use Exposure Delay Mode set for one second rather than Mirror Lockup or a Cable Release.

I usually set my camera for Single Images so each individual exposure is triggered with a press of the shutter.  It’s usually best to count the number of images that make up the multiple exposure.  If you select Continuous High or Continuous Low the camera will fire the entire sequence with a single press of the shutter.  That can be convenient, but you give up precise control and may introduce some mirror vibration.

As each individual exposure is completed, you’ll see the green light on the back of the camera which indicates the image is being processed.  After the final exposure, you’ll see the green light a second time as the image is written to the memory card.

Compared to ND filters

Multiple Exposures can be used instead of weak ND filters or in addition to a ND filter.  If all you need is a few stops, multiple exposures provide a good alternative.   But that’s not the only reason.

  • To blur fast moving clouds, multiple exposures with minimal time between exposures can simulate a ND filter.
  • Some ND filters pick up a color cast at 10 stops or beyond. Multiple exposures can be used for a series of shorter exposures and less color cast.
  • Multiple exposures can be used in combination with circular polarizers and other tools with less risk of vignetting.

There are a number of different ways you can use the in-camera Multiple Exposure.  For the sake of time, we’re just covering one technique here.  My most frequently used technique is to use multiple exposures with a Circular Polarizer and Lo 1.0 ISO for photographing streams.  The CP provides an additional 1-2 stops to slow the exposure as well as cutting bright reflections on foliage or water.   Another technique is to use it for close up flower photography by having one frame correctly exposed, then a second frame underexposed by one stop and defocused to create a soft blur behind the sharp flower.  For wildlife photographers, a multiple exposure burst of 1/30 sec. images while Continuous High can provide an interesting abstract of a bird taking off or flying.

Eric is a professional nature photographer leading workshops, providing private instruction, and selling fine art prints.  For more about Eric, visit www.bowlesimages.com .

 

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