It can often be helpful to have more working distance from your subjet when shooting close-ups. If the light is good and I don't need the extra distance I like to use the 50/3.5 Zuiko. For getting all the way to 1:1 without an additional tube the 55/2.8 Vivitar is handy. I have two of these. My favorite longer lens for close-ups must be the 138/2.8 Vivitar Close Focusing. It gets to 1:2 by itself. In OM mount I have a 90/2.8 Vivitar macro and in interchangeable mount I have a 90/2.5 Tamron SP (2nd version). If I need to get even closer I have an Olympus Auto Bellows as well as various extension tubes and teleconverters. Teleconverters are helpful in increasing magnification. The drawback is that you lose light as well as some image quality.