I've been wondering about macro lenses lately.
I have the Tamron 70-300mm f/4-5.6 1:2 macro lens. I also have a few achromatic close-up filters: Nikon 4T, Raynox DCR-150, Olympus B-Macro, etc.
But I've often wondered about getting a "true" macro lens, for these reasons:
1. Maybe it's me, but I never seemed to be able to get things very "big" when using the the Tamron 70-300. I've had more luck with the close-up filters, using a variety of zoom lenses (Tokina 80-400, Pentax 55-300, etc.)
2. The down side of the close-up filters, though, is the working distance. Different diopters give you different lens-to-subject distances, but you have to swap them out or add on to get much variance in the lens-to-subject working distance.
It seems like a "dedicated" macro lens might do a better job.
Of course, I'm pretty cheap, so I'd be looking for a Cosina-type 105mm f/3.5 lens.
BUT...I have read that particular lens is actually only a 1:2 as well, and requires an add-on filter to achieve true 1:1
So what I'm wondering is:
1. If the Cosina w/o the add-on is 1:2, is it any better than the 70-300?
2. With the add-on filter for the Cosina, do you get the same working-distance issues/limitation that you do with diopter-based add-on filters?
Thanks for any help in this!
Greg
Edit: I changed the title from "105mm" to 100mm. I had the Focal length wrong.
Last edited by gkreth; 09-09-2010 at 06:04 AM.