We are looking for more camera equipment to shoot pictures for our aikido demonstration and seminars. New camera lenses are quite expensive and since there are many photographers, there should be many second hand lenses for sale. There are several options available such as buying from ebay or amazon. Another site we found is http://www.usedlenses.net and it seem to carry lenses from major brands such as Canon and Nikon. We will do more research and compare prices to see which store offers the best deal. Getting a lenses is not simple since we have to make sure there are no issues with the lenses. The only way to find out is to ask the seller question and inspect the photo carefully.
Hopefully we are able to find more used lenses so we can take different pictures with different style and quality. It is also an art to able to capture certain postures.