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CHAPTER
NIGHT AND LOW-LIGHT PHOTOGRAPHY / Low-Light Landscapes

takes the view through the lens and angles it up

toward the eyepiece so that when you look

through the viewfinder, you are seeing the exact

scene that the camera will record. This makes it

really easy to see how the different focal lengths

are affecting your composition, and this helps you

determine exactly what to focus on. The problem

is that this mirror needs to be moved up and out

of the way before you can take any photos. When

the mirror is moved, it can cause slight vibrations

that affect the sharpness of your image, especially

at longer shutter speeds.

To counteract the vibrations created by the mir-

ror moving, camera manufacturers have come up

with a solution called mirror lockup. This feature

allows the camera to move the mirror out of the

way before the photo is taken to minimize vibra-

tions. Check your manual to see if your camera

has this feature. The way it usually works is that

the mirror moves out of the way the first time you

press the shutter release button, and the image is

taken the second time you press the button.

4. The shutter moves out of the way of the
   sensor for the amount of time indicated by
   the shutter speed setting.


5. The shutter closes.


6. The aperture is set to the widest point.


7. The mirror returns to the position so that the
   light entering the lens is now focused on the
   eyepiece, allowing the through-the-lens view
   on the camera.

There have been tests done using a laser pointer
that show how much vibration is caused when
you physically press the shutter release button on
a camera. It’s a lot, take my word for it. The solu-
tion is to use a remote control or cable release,
which I cover earlier in this book.

Another situation where there are vibrations is
when the mirror is moved up out of the way so
that the light can reach the sensor. This only
happens on dSLR cameras because of the way
they work. In the camera, there is a mirror that

ABOUT THIS PHOTO
The pier at Ocean Beach,
California, was in sharp focus
until the water came in and
moved the tripod just slightly.
Taken at 418 seconds, f/14,
and ISO 200.

10-9