On 24 July 2010 06:42, Mike Hord wrote: > Anybody know a good source for relatively cheap (say, <$0.50US ea) > (in qty 100) plastic lenses? > > Application is lensing down an IR beam to a moderately small angle. > If I could get the diameter down to 150mm at 10m, I'd call it a win. > I'm trying to make a laser tag game, so my receiver needs a wide > angle of acceptance, but the beam should be small. > > The smallest angle I've been able to find has been 5=B0, which puts the > beam diameter at ~1.7m at 10m. > > Google of course returns many results for contact lenses. > > Alibaba is an option but parametric search is abysmal. > > Buying a large number of cheap toys/flashlights is an option, if I can > find something that fits the bill. > > Yes, I know that the IR won't behave exactly as visible, but it may be > close enough for this project. > > Mike H. > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > Mike Have you looked in a local $2 shop (or your local equiv) for cheap magnifying glasses? Also I have seen credit card sized frenel type magnifiers used as advertising giveaways. If you could use them & find a source they should be well inside your budget. RP --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .