After all, we want the scene to hold perfectly still while we sample
shots at different focal distances. Having the camera also shake
and move around simply because I am holding it does not interest
me. I suggest we need a camera, a good lens, with both of those
mounted on a sturdy tripod.
The Actual Technique
Given that you have the camera securely mounted on a tripod, the
technique is quite straight forward. You aim the camera at a scene
you like, whether close-up (as in macro photography) or farther
away (as with landscape), and proceed to take several carefully-
focused photos at various focal distances. You will need to decide
what part of the scene you want to have in focus which for a
landscape shot may be the whole thing, but for a close-up shot it
could be just a flower. Let’suse a flower or a leaf as an example.
Starting at the very front most part of the flower, carefully focus at
the front edge and take a shot. Next, using the focus ring on your
camera, move it just enough to focus a little deeper into the subject
and take a second shot, and so on, until your final shot is one of the
far (rear) edge of the subject.
You now have a series of photos, each with a different focus point,
running from the front to the back of the subject. In each shot ,part
of the flower is in perfect focus while the rest of the shot (to some
degree) lacks focus. You might have as few photos as two or as
many as you like or feel you need. As mentioned earlier, if you get
into dozens or hundreds of shots, you probably need to have
special equipment, chiefly some kind of focusing rack to mount your
camera on that allows tiny evenly-spaced incremental movements,
etc. For reasons given above I am not going there in this article but
instead working with just a camera and tripod.
Once you have taken several layers of shots you are ready to
process the layers into a single photograph. You do this back home
on your computer using special software which you will need to
have. Some brands of focus-stacking software include:
Zerene Stacker (best)
Helicon Focus Adobe
Photoshop CS4
CombineZM