Water Power – Austin, Texas
Copyright © 2011 Jeff Lynch Photography
Shot taken with a Canon EOS 5D Mark II set on aperture (Av) priority using an EF 70-200mm f/4L USM tripod mounted. The exposure was taken at 70mm, f/18 for 3/10th of a second at ISO 100 using a Singh-Ray warming polarizer filter. Post capture processing was done in Adobe’s Lightroom 4.
Click on the image above for a larger version.
Using Mirror Lock-Up
We landscape photographers will go to great lengths and expense to get truly sharp images. For most of us, “sharpness” is the holy grail in our quest and we will spend whatever it takes in new lenses, cameras, tripods and filters to obtain the sharpest image. And yet, I often see well meaning landscape photographers overlooking the most simple and effective technique for eliminating camera shake, the leading cause of “soft” images; vibration!
Every DSLR made in the past ten years contains a mirror lock-up function and I’d be willing to bet that 95% of all DLSR owners have never enabled this important landscape photography setting. To understand why this function is so important you’ll need to understand what takes place in your DSLR when you press the shutter release.
- The mirror flips up (wham).
- The aperture closes down to the selected F stop.
- The shutter opens.
- The sensor is exposed to light.
- The shutter closes.
- The aperture returns to wide-open for viewing.
- The mirror flips back down.
Most of these actions occur with very little vibration but the mirror’s movement is the biggest exception. Enabling your camera’s “mirror lock-up” function will cause the mirror to flip up several seconds before the aperture closes down and the shutter opens. This few seconds is critical and allows the vibration caused by the mirror’s movement to dissipate before the shutter opens. Using this technique along with your camera’s self-timer function allows you to press the shutter release and then stand back while the mirror flips up and the timer waits a few seconds (usually 2 or 10 seconds) before opening the shutter.
A Small Caveat
If you plan to use mirror lock-up on your EOS DSLR, to help to remove any trace of shutter vibration, you need to be careful on bright days when there could be a lot of light entering through the lens. This is because the magnification of the lens could concentrate the light onto the shutter curtains and scorch them. To avoid this, don’t wait too long after locking up the mirror before taking the picture. Equally, with the mirror locked-up, you should not point the camera at the sun as this could also potentially damage the shutter curtains.
Also, when you use the self-timer and mirror lock-up you won’t be able to see through the viewfinder since the mirror is blocking your view. That doesn’t mean that stray light can’t enter the camera from the viewfinder and affect your exposure, so it’s a good idea to cover the viewfinder opening with the eye-piece cover as shown in the image below or with a baseball cap (my personal technique).