Pinning your exposure through spot metering

If you have read my last two blog posts then you are ready to read on, if not, you may want to read them first.

Whilst most people use their camera’s inbuilt meter there is still a strong case for having a handheld light meter.

Handheld light meters are arguably more precise than our camera’s exposure meter and the more sophisticated meters provide us with more information from which to base our exposure.

There are two handheld light meters that I recommend looking at that have spot metering capabilities built into them. They are

Both of these meters are very sophisticated and allow us to take both incident and reflected light readings, as well as measuring flash and providing the all-important spot metering capabilities.

When using a spot meter we are interested in

  • Midtones
  • Highlights
  • Shadows
  • Scene contrast
  • The dynamic range of our camera’s sensor
  • Settings the optimum exposure for our scene or subject

When taking spot meter reading we will do one or more of the following

  • Base our exposure on a midtone reading and set our exposure accordingly (camera or handheld light meter).
  • Take a highlight reading and make a +1, +2 or a + 3 stop adjustment to our exposure (camera or handheld light meter).
  • Take a shadow reading and make a -1, -2 or a -3 stop exposure adjustment (camera or handheld light meter).
  • Take a reading from our most important highlight and shadow area and average out the two exposures ( best done with a handheld light meter).
  • Take multiple spot readings and average them out (best done with a handheld light meter)

Remember, all subjects have different reflective qualities

Reflected light metering measures the light reflecting from your subject and depending on how dark or light your subject, provides you with reading.

Because of these different reflective qualities and to get the optimum exposure for our subject or scene, we need to evaluate the scene and adjust our exposure accordingly.

When shooting with digital you need to be very accurate with your light readings. Unlike film, which has a wider latitude when it comes to your exposure, digital (especially JPEGs) requires you to be spot on with your readings.

Some examples

In time you will learn to judge how light or dark a subject is and set your exposure accordingly.

 

Highlight reading adjusted by +2 stops
Midtone reading from rocks, no exposure adjustment. Image converted to black and white.

The next example uses a number of spot readings averaged out to give the correct exposure. The readings were taken with a Sekonic L758 light meter in spot meter mode and then average them out.

Multiple spot readings averaged out

This was a high contrast scene and difficult to expose for. Handheld light meters are invaluable for scenes like this.

Shadow reading -2 stops

In our final example, I have metered from my most important highlight and shadow areas. The difference between the highlight and shadow areas is 7 stops, my camera’s sensor can handle 12 stops.

This is one of my favourite ways to meter as I know that the contrast range of my scene falls within the dynamic range of my camera’s sensor and that I have pinned my highlights and shadows to the correct zones, optimising my exposure. All of the other tones between my highlights and shadows fall into the correct zones.

Learning to meter like this can be very rewarding. You are taking control of exposure and making sure that your scene or subject is correctly exposed.

Remember: Light meters measure the intensity of light. There are two types of metering, incident and reflected.

Incident metering measures the intensity of light falling on the subject and
providing that we can measure the light falling on our subject, it is by far the most accurate way to ascertain the correct exposure for our scene or subject.

Reflected metering measures the intensity of light being reflected by our subject. Because of the different reflective properties of our subject or scene this intensity of light differs. Dark subjects reflect less light, bright subjects more.

It is because of these different reflective properties that we need to take control of our camera’s metering and adjust or apply exposure compensation as necessary.

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