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HDR - the Nuts & Bolts


Full Moon over Dallas & Deerfield Holiday Lights

Guy Huntley Photography
October 17, 2017
Copyright©GuyHuntleyPhotography

Also check :
HDR - the Software

Look at the Software

I had been hearing a lot about HDR photography. But it sounded weird. That evening the club was meeting for a 6 PM Happy Hour at the Metro Grill. The building was facing east. The light was awful. I didn’t have a strongly recommended tripod. What did I have to lose! Canon 20D 24mm @ f / 5.6. After seeing this image, I was hooked on HDR.

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The big reason is I can photograph in broad daylight without worrying about harsh shadows. I’ve photographed Bryce Canyon, New York City, and many places in between. There simply aren’t enough dawn and dusk hours.

And we avid amateur photographers aren’t like those rich, overpaid, professional photographers who can afford to lounge around all day drinking beer and wine at the local bistro waiting for those all too few magical golden hours!

  • Both of these venues have very high dynamic range.

  • Trinity Groves with the moon in full daylight (28 EV) more so than
    Deerfield holiday lights (21 to 23 EV).

  • If you can get beautiful images at either of these two venues,
    you will be well on the way to capturing beautiful images everywhere!

  • The difficulty is the magnitude of the dynamic range.

  • Typical daytime scenes are in the 15 to 17 EV range using 3 exposures 3 EV or less apart.

  • The rest of this presentation will look at settings and techniques for both of these venues.

  • The November meeting will answer any lingering questions and demo HDR software.

The EV of 12 was picked as roughly daylight. We all know the relationships between aperture to depth of field and time to freeze action. But take a look at what happens to the Dynamic Range (DR) and the Signal to Noise Ratio (SNR) as the ISO increases.


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Everything is a trade off!

Below are charts for Trinity Groves & Deerfield. Trinity Groves goes from full daylight (the moon) to night. The Deerfield lights are about two stops darker than daylight. The best settings for most of us are F / 5.6 @ ISO 1600. Faster glass (F / 2.8 or F / 1.4) allow us to lower the ISO and / or increase the speed.

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While the moon's exposure at 11+ EV was the same, the back yard was about two stops darker than Trinity Grove. ISO 2000 was used in the back yard to avoid waiting 8 minutes to complete the ISO 400 exposure.

Who cares if a back yard picture is noisy? This is practice!

The settings for Trinity Groves and Deerfield shown below are ISO 1600 @ F / 5.6.

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The F / 5.6 setting was chosen because everyone has a F / 5.6 lens. Faster lenses may be rented for a week end at Aperturent.com or Competitive Camera. Clearly, faster glass is a huge help to reduce the ISO and / or the shutter speed.

The 1600 ISO was selected to keep the longest shutter speed less than 30 seconds out of the dreaded "Bulb" mode. If the ISO is dropped to 400 the longest shutter speed increases to 120 seconds.

The next two charts show Automatic Exposure Bracketing (AEB) settings for most cameras.

There will be no problem if the settings recommended above are used. However, it is always wise to check our exposures!There

Checking the exposure for shadows is easy. If more than half of the right side of the histogram has shadow detail the image is good. There should be NO shadow detail blockage on the left. This is true whether the image is at high noon or the darkest night.

But checking the highlights at high noon is different than dark night. The Highlight histogram works great at high noon as shown on the next slide. But on dark nights the only way to verify the exposure is to pixel peep the final image to see if the moon or colored lights have the color you saw as shown on the 2nd & 3rd slide following.

Blown out colors cannot be retrieved in post processing. I have tried!

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13 exposures separated by 1 EV, ISO 400 @ f / 5.6, T from 30 sec to 1/500 sec;
Canon 5D Mark iv with EF 100 - 105 mm @ FL 41 mm

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  • One exposure at a time changing settings after each exposure

  • Use the camera's Automatic Exposure Bracketing (AEB)

    See charts below for using in Very High Dynamic Range scenes

  • Use Free or Near Free Phone apps like DSLR Remote

    • Make certain the app supports HDR exposure bracketing

    • You may need On the Go (OTG) USB adapter for your phone

  • Use Helicon Remote for $48.00

    • You may need On the Go (OTG) USB adapter for your phone

  • Use Cam Ranger for $299.99

  • Use Promote Contrul for $329.00

At one time or another I’ve used all six of these.

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Deerfield is forgiving. There is plenty of time to learn. But the moon rises over the Dallas Skyline discouragingly fast. There is no time to experiment and learn. The next opportunity is this time next year!

If you decide to use one of the phone apps, you will need an "On The Go" (OTG) cable to connect to your camera.

It is best to keep the exposures to two EV or less. One pro won't go more than 2/3 EV. That's a little too radical. Experiment with 1 to 2 EV spacing.

Practice on Street Lights, House Security Lights, and whatever is left of the moon! We need good exposures for both shadows and lights!

Last Thoughts

Trinity Groves:

As the full moon rises from behind the beautiful Dallas Skyline, a lens supporting a 200mm to 400mm Focal Length FF (125mm to 250mm APS-c) will create the most spectacular images. As the moon rises further a lens in the 24mm to 70mm (15mm to 45mm APS-c) will create beautiful images of the skyline, the Margaret Hunt bridge, and maybe even the Texas flag.

Deerfield:

The focal lengths ranged from 24mm FF (15mm APS-c) to capture the entire front yard up to 70mm (45mm APS-c) to zoom in on some of the details.