Need a macro lens for a Pentax K-X DSLR. This is my first experience with DSLR so need some advice please. The camera will only be used in doors for dental photography most likely with a ring flash. I have seen the Tamron lens on offer at Jessops. Tamron 70-300mm Lens for Pentax + Jessops UV 62mm Filter - Jessops - Lenses What are peoples view on this lens? Is it a good lens to go for? Any other good lens people can recommend that would be suitable? Thanks.