Old lenses can be interesting for their optical affects, or they can just look plain dull -not quite sharp, flat, sort of second-rate feeling. If you want to get wild and crazy, look up the thread on swirly bokeh to learn more about what lenses give great effects (many of them are larger format, but no worries). Ask people on this forum like Jim Galli for advice on what kind of lens will give you what kind of effect.
Have fun!
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