You may find the kit 18-55mm as good as anything for this purpose. It has good resolution, and gets pretty close. At macro distances, you do not need a fast lens, since you will need to stop it down for depth of field. For images of the size that go on a web site, you have a great deal of cropping room on a D3200, which will allow you to stand back some and gain some depth of field if need be, and then crop in. Remember a 24 megapixel image will print to poster size. I've gotten pretty decent full screen shots from a digital camera with a tenth the density.
Lighting will be more of a challenge than lens choice. I suggest you shoot in Raw mode so that you can tweak the white balance and picture mode easily. Be prepared to experiment with background colors that compliment your product, and multiple light sources that reduce shadow.
For jewelry and the like, if you really want a true macro lens, a relatively short focal length will probably do fine. Longer focal lengths block less of the ambient light, and are very nice if you're chasing bugs and whatnot, so you don't scare them away, but jewelry is pretty placid, and a long lens might require you to stand way back if your jewelry is bigger than a ring or a bracelet. I'd look at the 40mm macro, which is said to be pretty sharp, and is a length you can use as a normal lens too. But I'd try the kit lens first; it might surprise you.
Comments
Lighting will be more of a challenge than lens choice. I suggest you shoot in Raw mode so that you can tweak the white balance and picture mode easily. Be prepared to experiment with background colors that compliment your product, and multiple light sources that reduce shadow.
For jewelry and the like, if you really want a true macro lens, a relatively short focal length will probably do fine. Longer focal lengths block less of the ambient light, and are very nice if you're chasing bugs and whatnot, so you don't scare them away, but jewelry is pretty placid, and a long lens might require you to stand way back if your jewelry is bigger than a ring or a bracelet. I'd look at the 40mm macro, which is said to be pretty sharp, and is a length you can use as a normal lens too. But I'd try the kit lens first; it might surprise you.