rgmichel Loc: Connecticut

I would like to learn more about macro lenses. What are the issues that drive the choice of a macro lens? My impression is that most favor a longer focal length, 90mm and up? What are the advantages and disadvantages of the various macro focal lengths? Is a macro zoom a good choice? Do macro zooms perform almost as well or as well as a prime zoom? I plan a macro purchase for my Canon 6D (which is due for me to upgrade BTW) What are the pros and cons of using a macro lens with a full-frame or APS-C camera?

Blurryeyed Loc: NC Mountains.

If your budget can afford it I would suggest the Sigma 150mm lens, it is a beautiful lens and has great optics. You can't hardly go wrong with any macro lens, Nikon, Tokina, Sigma, they all do a great job. I have done a bit of macro over the years and have had friends that have own different lenses and as I said earlier they all do a great job, find one that has the features you want and a focal length that may be beneficial to you for more than just macro and make your purchase, you can't go wrong.

Blurryeyed Loc: NC Mountains.

Just about any macro lens is good, the longer the focal length the creamier the background blur, but the longer lenses, 180mm and 200mm require a very steady camera because motion blur becomes a greater issue, pretty much the same as the difference between a short focal length and long telephoto when taking handheld shots in general photography only with macro the issue is exaggerated because you are focused so close to the subject and are generally shooting with a small aperture. The longer lenses not only give a more pleasing background but also give you a greater working distance, the distance between the end of your lens and your subject. A good flash solution goes a long way to remedy the blur problem and in general improves your macro experience.

Below is an example of background blur created by different focal lengths, notice the difference between the 180mm on the left and the 60mm on the right.