I found this link for a Depth of Field Simulator by Martin Waugh that would be very useful for understanding this DoF concept/issue:
Java-Enabled Depth of Field Simulator
Note that you will need to install the Java2 plug-in (if you don't have it already) but there is a download link on the DoF simulator page for it. Some operating systems may require a system restart to enable it after installation.
Java-Enabled Depth of Field Simulator
Note that you will need to install the Java2 plug-in (if you don't have it already) but there is a download link on the DoF simulator page for it. Some operating systems may require a system restart to enable it after installation.