Pros: Fantastic lens, optically spectacular, great bokeh, contrast, sharpness
Cons: AutoFocus not blazing fast (but not a problem with macro)
In modern times, when folks consider cameras, one often hears the name of the big two manufacturers--Canon and Nikon. And while it's true that they have captured the professional market for 35mm users, that doesn't mean that other manufacturers don't have good, or even spectacular gear.
Minolta's 100mm f2.8 macro lens is a specialty lens that offers all round uses. Equipped with true macro functionality, you can get up close to your subject matter and reproduce the image 1:1 on 35mm film. This means you can get images of small things and then blow them up really large as a print. In looking at the world around you in such a manner is often inspiring as well as eye opening.
Note that the Minolta 100mm macro is more than just for shooting flowers and bugs. You can also use it for taking portraits as well as shooting landscapes and the like. For me, the lens is so muliti-functional, it never leaves my camera bag.
So how good is this lens?
In December of 2001, Colorfoto (a german magazine) ran a test on various macro lenses. Not surprisingly, Leica's 100mm macro APO was the highest rated lens--optically speaking. Surprising to non-Minolta users, is that the 100mm f2.8 macro from Minolta tied the Leica lens in terms of score. The elements the testers used to rank the various lenses were things such as color contrast, distortion, sharpness and the like.
The Colorfoto test results don't surprise me. People I show my photographs to consistently comment on the image quality produced by both my Leica optics as well as my select Minolta gear. The 100mm 2.8 Macro lens is truly part of my select Minolta gear.
The construction of this lens is sturdy. Solid. It comes with a lens hood, which you should use to prevent flare. The lens is autofocus capable, but of course can be used manually as well. When attempting to take Macro shots, once should both use a tripod as well as focus manually. Manual focusing is smooth and easy. The manual focus ring on the lens is thin/narrow but I haven't had a problem in using it.
Aperture, relates to the amount of light that comes through the lens to hit the film in the camera. The maximum aperture on this lens is f2.8, which is a pretty large opening. A lot of light comes through this lens, which means that you can use it to get shots in some less than stellar (as in kinda dark) lighting conditions. There are 9 circular aperture blades which (I think at least) are constructed in a way so that the out-of-focus areas in the picture are of soothing, pleasing quality. (the term for this out of focus area is known as "bokeh" and though some photographers poo-poo the concept, others of us, particular those that shoot landscapes, portraits and macro shots definitely WANT the background, out-of-focus areas to be non-distracting, even pleasing to the viewer.)
Back to auto-focus. I don't use AF when doing macro shots. BUT I use this lens a lot when taking portraits, or when shooting as a short telephoto lens. In those situations I tend to use AF about 50% of the time. There is a focus range limiter on the lens...which basically allows you to "narrow down" the range of focus that you want your autofocus to focus from. Sounds complex, but basically this allows you to tell the camera lens what range of focus you're looking for and therefore also speed up the AF function.
The cost for a new lens isn't cheap. If you can find an excellent used one, go that route. If you have to buy new and don't have the money, simply save your pennies. At the cost of $500-$600 you will have a superior optical device that is equal to a Leica lens. If you take good care of it you will own it your whole life. If you learn how to properly use your camera and take decent shots, then the images you obtain from this lens will be something you can hand down to your friends, children as well as share with others through the web, or even galleries.
I find it endlessly amusing that people will bemoan the cost of a superior piece of optics that will last a lifetime, and yet then go out and spend the same amount (or even more) on a digital camera that will be lucky to last 5 years.
So, to summarize, this lens is excellent in terms of optical as well as build performance. The only real limitation in using this lens will be yourself.
Buy it. Use it. Enjoy it. And above all, make great art.