vibration resonating through the camera body. For most work this
vibration is not a big problem, but for very exact work with longer
shutter times (or using a longer lens in macro mode) it takes time
for the vibration generated by the mirror slap to dissipate.
This is why the better DSLR cameras have what is called a “Mirror
Up” feature that allows you to press a button and have the mirror
slap up and resonate, but not take the photo. Pressing the button a
second time (after waiting for the mirror-up vibration to die down)
actually takes the photo. It is a two-step process. Not all cameras
have this, but if you are a macro shooter, you need to have it. I use
it for almost every photo I take. To repeat:
Close-up, macro, and especially focus stacking requires that the
camera not vibrate or shake. The large DSLRs from Canon and
Nikon all have to get the mirror out of the way of the viewfinder
when a photo is taken and the ‘slap’ of the mirror slamming up is
enough to cause vibrations that affect the quality of the photo
especially at long shutter speeds.
So, as mentioned, most high-end camera bodies have what is
called a “mirror up” mode which allows you to click the shutter
twice, once to move the mirror up and out of the way, and the
second time to actually take the photo, after which the mirror slaps
back down but too late to affect the photo by causing vibrations.
The bottom line is that you want to get a camera body that allows
you to park the mirror up before each shot and let the mirror-slap
vibrations die down. If your camera does not have this feature, you
are at a disadvantage. Look for this feature to be present before
you buy a camera for macro work.