Originally posted by andyph666 I have the K-5 with Tamron 17-50, Pentax DA 50-135 and a Sigma 8-16 incoming. I am looking for a macro lens and have narrowed it down to the 35mm or 100mm DFA WR Pentax macro lens. Any ideas what I should choose since I have a few lenses already? Thanks.
The big difference in using these two is "working distance": how close you are to the subject. They can both reproduce a subject life-size, but you have to get really close for the 35mm, farther away for the 100mm or 90mm as suggested. That makes the DA 35mm f2.8 Limited more of a small, sharp normal lens with macro available, but not ideal for snakes.
Other than working distance and magnification, dedicated macro lenses are very well-corrected, so when the focal length and speed are within a usable range, you can use them for other subjects. So you can choose a focal length where you might also use it for portraits or a normal lens or short telephoto or something else.