There is nothing to beat a dedicated Macro lens Anthony I use a Sigma 105mm its got a wide 2.8 aperture and works both on my Canon10D and EOS1 film cameras they make a Nikon fit bear in mind this will be more like 160mm with the 1.5 magnification factor on your D70 and you can get real 1:1 ratio its well within your budget too perhaps you can use the extra to buy a ring flash which will give wonderful light you mentioned you were having problems with.. Other possibilities include the use of extension tubes etc or bellows but this may be limiting to take into the field.. Focus is not so much a problem with macro work as often you can just move in and out until it is bang on the DOF however is another matter as it can be very shallow.. please let me know if you want any more precise advice Danny

Danny O'Byrne  http://www.digitalartzone.co.uk/

"All the technique in the world doesn't compensate for the inability to notice" Eliott Erwitt