> I am green when it comes to macro work, but I have recently purchased a 105 > macro. What happens to reproduction/mag ratios when you add a 1.4 > Teleconverter? Or, is this not advised? Your question, largely a 1.4 converter will give you close to 1.4 increase in magnification. It might not be exactly that if you use a micrometer to measure it because the 1.4 quoted will be "at infinity focus" but I suspect any difference is trivial. Using all Canon stuff I prefer to add a "teleconverter" (1.4 or 2.0 x) whenever possible instead of excessive lengths of extension tubes. In my experience the theoretical loss of resolution resulting fron the inclusion of any glass elelments anywhere is more than offset by the fact you are using the lens closer to it's "designed". Much of the "loss of resolution" is simply that you are multiplying what is there anyway. But if you need to go to 1.4:1 life size, the teleconverter will give a better print size for size than cropping and blowing up the image captured at 1:1. Of course, for digital cameras "cropping" is now correctly called "focal length multiplication" ;o)
