Sigma's 105mm ƒ/2.8 macro lens is quite similar to Nikon's own 105mm ƒ/2.8 macro lens (or micro lens, as Nikon calls them). But it's priced significantly lower, especially when you can get a good deal on it. It's a 105mm prime, has autofocus, as well as built-in lens optical stabilization.
The 105mm focal length is my favorite macro length for the simple reason that I find it the most versatile for my needs. From product photography to close-ups of flowers, I find the 1:1 magnification it offers to be something I reach for often. But one of the things I like about these lenses is that they're not just macro lenses. I find them surprisingly versatile for general-purpose and even portrait photography (although other specialized lenses like Nikon's 105mm ƒ/1.4 is even better for that, it's also much more expensive). It wouldn't necessarily displace something like a 28-70mm or 70-200mm in my travel photo kit, but it can nevertheless come in handy. So I've included in the sample images below a mix of traditional macro shots as well as more general-purpose travel style photos.
Most of the time I use Nikon's 105mm ƒ/2.8, and I've used the past two generations of that lens. But I've recently been shooting with Sigma's 105mm ƒ/2.8. Or, more technically, the Sigma 105mm f/2.8 EX DG OS HSM Macro Lens.
There are versions for Nikon and Canon; I've been using the Nikon version. These were all taken with a Nikon D810 and processed in Lightroom. I've not applied any of Lightroom's lens corrections such as chromatic aberration or lens profiles to these.
You can click on each image to open a full-size version if you'd like a closer look.
Sigma 105mm f/2.8 EX DG OS HSM Macro Lens Sample Images
Find Them At
The Sigma 105mm f/2.8 EX DG OS HSM Macro Lens is available with Nikon and Canon mounts--you can find them at B&H Photo. At the time of writing, they're offering a $400 instant savings (down to $569), which is an excellent deal.