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