Want to get a macro lens don't know which one to get?

So i'm thinking of purchasing a macro lens cause i love the idea of macro photography i just haven't had the money nor the correct knowledge of what to get. So i was looking at a sigma 50mm macro (i have a nikon d7000 camera) but i also have a regular 50mm lens. So is there a big difference or should i wait a little longer and save up the extra money to get a 60 or 100mm macro! Or is there any other thoughts about this?

The longer the lens, the further away from the subject you will be when shooting at the macro settings of 1:1, 1:2.etc. In addition, the longer lens will have less depth of field at any given lens aperture when compared to the 60 mm lens

The two most popular macro lenses used with the D7000 are the AF-S 60 mm f/2.8 and AF-S 105 mm f/2.8 macros

I have a Sigma 50mm f2.8 macro lens with a Nikon D300 - an excellent lens in my opinion - I use it for macro, but it's also a good portrait lens too.

The difference between it and your 50mm f1.8 lens is that it can close focus to produce a true 1:1 (life size) image on the sensor.

The working distance between the 50mm macro lens and the subject will be less than with, say, a 105mm macro, so it depends on what you want to photograph - subjects which might be skittish & easily spooked might benefit from the greater working distance of a 105mm macro. Incidentally, the Sigma 105mm f2.8 macro is also an excellent lens - I don't have one but a couple of friends do & the results are tack sharp.

Here's a few of shots I've taken with the Siggy - a couple of macros & a portrait;

It depends entirely on the kind of images you intend taking.

Give us some more information. For example is it for:

1.photos of tiny inanimate (or dead) objects - and real close up, like insect compound eyes and so on.

2.photos of flowers/butterflies or similar sized small objects - but not microscopically close.

3.photos of insects, close up, in the wild (still alive)

You could certainly use a 60mm macro for 1 and 2. But 100mm macro would be better for no 3. Give the 50mm a miss.

It all comes down to how close you can get to the subject before it flies off.

Focal lengths of 100mm or more are good for insect subjects, where a longer lens-to-subject distance is desirable. Anything less can be used too, but you may get some missed opportunities since you'd have to get closer to the insects. Static subjects like flowers are fine for a 60mm Nikon micro lens. I personally prefer Sigma's 70mm macro for most close up work. It's THE SHARPEST lens I've ever used, even compared to Canon's L glass.

Whatever macro lens you choose, don't worry. They're all good. I've never met a macro lens I didn't like.