I am setting up AstroImageJ for the first time. On page 32 of the User Guide it instructs me to change the Aperture Photometry Settings from what they defaulted to when I downloaded the latest version of AstroImageJ to what they show in the User Guide. For example, the User Guide says the "Radius of object aperture" should be set to 30, but the latest version of AstroImageJ has this parameter already set at 25. Should I change such parameters in AstroImageJ to match the User Guide, or leave them as they are? Thanks.