The answers to many of the questions that we ask can be found in the archives, b ut finding those answers can sometimes be difficult. I have found the "Advanced Search" function of Google to be an easy way to search the archives.
To use this method, visit http://www.google.com/advanced_search. Enter your search terms, and then en ter hv.greenspun.com in the "Domains" box (below, and to the right of the boxes for the search terms). Then run the search (click on the "Google Search" button toward the top of the page). By entering hv.greenspun.com, you are rest ricting your search to this web site.
Because there are many different forums in this site, you may need to make your terms specific ("90mm lens" instead of "90mm"). You may still get some threads that are from different forums, but all of the results should be from this site, and not from the web in general.