Local camera "shows" might be a good place for you to look - the glass is sold by RITZ so you could check with them - also I am a firm believer in buying the manufacturers own glass - it costs more but you will always be able to get accessories for the glass and in most cases the glass is much better quality. I recognize for some this is no issue but if you ever need to resell you equipment - something I do ever 18 months - you will find the aftermarket glass - tamaron, tokina - vivitar - and quantaray all suffer major hits because they are less expensive alternatives to factory glass...