Here is my photo for the day:
And here is an experiment. I've been having a little difficulty figuring out depth of field (DOP), especially when it comes to macro. If you are good in math, there is a handy calculator that you can use: http://www.dofmaster.com/dofjs.html.
I, however, have been having some difficulty using the calculator, so someone from the photo chatboard I frequent suggested that I try an experiment to help me understand DOF better. What I did was take a photo of my orchid from 5 feet away with an aperture of F2.8, then F4, F5.6, F8, F16, and F22. I did the same thing from 3 feet away and then 1 foot away. I already knew that as my aperture gets smaller (which is actually represented by the larger number; i.e. F2.8 is the largest aperture in the experiement and F22 is the smallest aperture in the experiment) that there will be more in focus, so there will be a larger DOF. A wider aperture will create a shallower DOF. The experiement helped clarify for me, however, that being closer to your subject will also create a shallower DOF. Therefore, if you get closer to your subject, less of your subject will be in focus unless you make your aperture smaller. This is very important to understand when using a macro lens because I would normally use a large aperture, like 2.8 or even larger, when photographing a flower in order to get some nice bokah, but with a macro lens, I might be too close to my subject, and I won't be able to get much of the subject in focus with an aperture of 2.8. It still might be a cool photo, but it will probably be more abstract. I want to thank Michele Louise for suggesting this experiment to me because it has really help clarify DOF for me. I don't know how well you can see all of this from the photos, but here they are:
From 5 feet away; F2.8:
From 3Ft; F2.8:
From 1Ft; F2.8: