Best Aperture for Focus Stacking?
The best aperture is whatever is the sharpest aperture for the lens
you have. You are not looking for depth- of-field here because that
is what you will simulate by stacking focus, so don’t stack at f/11 or
f/16 just because you may get more DOF. Go for the aperture
where your lens is the sharpest, which is usually around f/4-5.6 for
most lenses. Let the stacking give you the sense of greater depth-
of-field.
Focal Length
You can stack with pretty much any lens, but keep in mind that the
wider the focal length of the lens, the less you need to turn the
focus ring for each layer. And most wider-angle lens do not have a
long focus throw so just a tiny movement may be enough. If you are
stacking with lenses that are 100mm or longer, a lens with a very
long focus throw is a real help.
I routinely stack with lenses from 35mm to 200mm, most of them
being macro lenses.
A Good Tripod
There are focus stackers who use no tripod, like as kids we would
ride a bike and yell out “Look mom, no hands!” I don’t go there and
if you want stacks of 6-10 or more layers, it for sure won’t work. Get
a good tripod and ball head. Use them.
grass cannot but keep the formWith focus stacking, especially in
early morning or dim light you need a fast lens, not because you
are shooting wide open but because you need enough light in the
viewfinder to know where your key points of focus are. A lens of
f/2.8 or faster is a real blessing in “magic” light of dawn and dusk.
Focus Increments
There is no set rule here but you want your increments short
enough so that the overlap between shots (from the DOF your
aperture is set to) is enough to merge well. Some shooters use a
focus rail. I just use the focus ring but often move the ring just a tiny
bit in each shot. This is something one has to get the hang of.
Focus Throw
A long focus throw while not useful in sports or action photography
is very useful when stacking focus. I was surprised at how short the