I'm sure it matters how critical your applications are. In my case, I was told the prior owner was a "defense contractor", so who knows what they did with it....but I can say that for my purposes, which are mostly to have a good time and (eventually) learn to take pictures, it's 'way more than good enough. I do plan to take apart that which can and should be taken apart and clean it, one of these days - the eyepieces are a little dusty (so thanks, Tim, for the advice about cleaning). Today I studied the edges of my fingernails. I would recommend that gardeners *not* do this. It can be alarming. At least I didn't see little wiggly things. Ellen On Mon, Mar 3, 2014 at 6:09 PM, Chernoff, Ellen A. G. <echernof@iupui.edu>wrote: > Tim Eck is right that it is not easy to abuse this kind of scope with > ordinary care, but if it was used in a microlithography lab where they > etch silicon wafers with hydrofluoric acid, there isn't an unetched > piece on the scope. And student scopes have the damndest things done > to them. > --Ellen C. > > -- > Dr. Ellen Chernoff, Ph.D. > Associate Professor of Biology > IUPUI-Biology SL 360 > 723 W. Michigan St. > Indianapolis, IN 46202-5132 > 317-274-0591 > > _______________________________________________ > pbs mailing list > pbs@lists.ibiblio.org > http://pacificbulbsociety.org/list.php > http://pacificbulbsociety.org/pbswiki/ > -- Ellen Hornig 212 Grafton St Shrewsbury MA 01545