How Light falling on a subject affects shape and contour

 How does the direction light is coming from affect the subject? Here are some late afternoon shots taken at the local fruit stand which illustrate how shape and definition change depending on where the light is falling.

Front Lighting
Late Afternoon February 2013

Front lighting gives good detail on the surface of the oranges.
Oranges would appear somewhat flat if it were not for the
low angle of the sun and the stacking

Side Lighting
Late Afternoon February 2013

Low angle sun coming from the left makes
distinct highlight and shadow sides of the oranges.
Oranges appear very round.

Back Lighting
Late Afternoon February 2013
Camera is pointed almost directly towards the sun.
The majority of each orange looks dark.

The rims of the curved tops of the oranges are highlighted.
Some detail shows in the shadows because light has
bounced off the pile of oranges, illuminating the back side.

Photo of the Week - February 22, 2013

Hellebore in Bloom

February 22, 2013

Photo of the Week - February 4, 2013

Great Blue Heron plunges its head into Nisqually Estuary
while hunting for lugworms

Nisqually National Wildlife Refuge
Olympia, WA
February 4, 2013

Lugworms live in U-shaped tubes beneath the mud of the Nisqually Delta. Lugworms leave castings of mud that has passed through their guts which are visible on the muddy surface. My friend and I watched this Heron for over an hour as it ate at least a dozen of the worms, which can be up to 7.75 inches in length.

One fascinating lugworm fact - the lifespan of a lugworm is estimated to be 5-6 years!

Great Blue Heron with lugworm
Nisqually Refuge


Mirror Slap and Camera Vibration at Slow Speeds

While photographing close-up images with my macro lens, I noticed something very curious. As I increased the depth of field for the images, they were becoming less sharp. I ran down my mental list of potential culprits and was unable to come up with a solution.

I was...

  • shooting on a tripod with legs and head firmly locked
  • shooting with the remote cable
  • shooting where I didn't expect ambient vibrations from machinery or foot steps
  • not using image stabilization/vibration reduction
    (the lens I was using didn't have it)
And then I remembered one of those long-ago lessons from photo school...
  • the mirror of an slr camera can cause the camera shake when it lifts during an exposure
Shaking caused by a mirror is called 'mirror slap'. It has almost no effect on shutter speeds faster than 1/60 second or longer than 1 second. It can be quite disruptive at shutter speeds between 1/45 second and 1 second.

See the example photos at the bottom of this post to see the effects of mirror vibration. You will want to click on each photo to enlarge it to 100% to see the image clearly.

The solution to mirror slap is to either lift the mirror manually (mirror lock-up) or delay the exposure until the effects of mirror slap have passed.

The mirror lock-up feature is uncommon on digital slr cameras; most cameras feature either an exposure delay or two-step shutter release.

Some examples of how to avoid mirror slap:
Canon dslr cameras:
  • set your camera to P, Av, Tv or M mode
  • go to your custom settings menu
  • find the mirror lock up setting and enable it (this is not the sensor cleaning setting!)
  • use your remote to shoot the photo
  • when you depress the shutter, the mirror will pop up
  • depressing the shutter a second time releases the shutter and takes the photo
  • when you have finished taking photos, reset the custom setting to disable mirror lock-up
Notes: When mirror lock up is used in conjunction with the self timer, the shutter button needs to be depressed only once - the shutter will fire after about 2 seconds.

Live View also lifts the mirror out of the way to avoid mirror vibration.

Nikon dslr cameras:
  • set your camera to P, A, S or M modes
  • go to your custom settings menu
  • find the exposure delay setting (d10 on many older cameras, d4 on some newer cameras)
  • use your remote to shoot the photo
  • after the shutter is depressed, there will be a delay of about 1 second before the photo is taken
  • when you have finished taking photos, reset the custom setting to disable exposure delay
Nikon d7000
  • set your camera to P, A, S or M modes
  • set your motor drive to M UP (it is on the upper left side of your camera body)
  • your viewfinder will go dark
  • shoot your photo with your remote
  • reset the M UP back to single or continuous when finished
Note: the d7000 also features an exposure delay custom setting d11


Example photos showing the effects of camera shake caused by mirror slap.

click on photo to view at 100% magnification
1/125 sec. at f/4
click on photo to view at 100% magnification

1/30 sec. at f/8
click on photo to view at 100% magnification

Add 1/8 sec. at f/16
click on photo to view at 100% magnification


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