I am interested in stepping into the world of macro photography...mostly for weddings (cake, rings, flowers, etc) as well as bugs, flowers, etc around the house/trips. I shoot Nikon and I am wondering people's thoughts on the Tamron 90mm vs. the Tokina 100mm macro lenses? I would love to stay Nikon and go with the Nikon 105mm VR, but I can't really justify the price difference if one of these two lenses will be just as good at half the price, since this will be mostly a fun lens and only used for 10 or so shots during a wedding. Right now with the Tamron rebate, both lenses are $400 at B&H. Thoughts? Thanks in advance.
Cake and flowers? How small are they? I'm just kidding mate.
With macro lenses, only two things really differentiate a lens, the price and focal length. Bokeh difference is negligible as I've seen samples of 90, 100 and 105 and they're all very similar. Sharpness, macro lenses are known for their sharpness so the only thing you need to worry is the copy variation.
Too bad you're a Nikon shooter, otherwise I would recommend the Canon 50mm f/2.5 1:2 Compact Macro which should be more than enough for your wedding shots. As it is, perhaps you can try Sigma 50mm or 70mm f/2.8 1:1 macro. I think they're smaller, cheaper and yield similar result. Otherwise go with the Tammy.
The tamron 90 is a fine lens, I used it for a long while on a D70, then a d200. The lens was stolen from me and I tried the Sigma 150 (which I hated despite everyone's glowing reviews, mine was *not* sharp), I moved to the CZ100/2 which I liked but couldn't deal with the no AF during fashion shoots (my primary modus operandi) and finally settled back on the Nikon 105 VR. I really enjoy the nikon, and I heartily recommend it to anyone interested in a serious macro lens. Very very sharp and comfortable to handhold. It stays on my D300 more than any other lens.