kpmac wrote:
...The Tokina 100mm is great for macro and portraits and is relatively inexpensive....
In Nikon mount, the Tokina 100mm macro is a motorless "D" type lens.... will not be able to autofocus on a Nikon D3000 or D5000 series camera.... Can only AF on D7000-series and higher models that have a motor in the camera body to drive the AF of those types of lenses.
I agree that manual focus isn't a big deal shooting macro... but if you buy the lens intending to also use it for other, non-macro purposes, you may be disappointed.
There are lots of other good macro lenses that can provide AF.
For example, on an APS-C camera like the original posters a Tamron SP 60mm is a good, dual purpose "Di II/crop only" lens
with autofocus. It's also an f/2 lens, at least a full stop faster than most macro (and only 1/3 stop slower than a 50mm f/1.8 or 85mm f/1.8). Plus it's both reasonably compact and internal focusing (doesn't grow longer when focused closer, further reducing working distance, the way many of the more affordable macro lenses do). The only significant short-coming of this lens is that it uses a micro motor which makes for slower AF... it's not up to shooting sports/action, but is fine for macro, portraits and most other purposes. Note: macro lenses in general tend to be slower focusing by design... first, they have to move their focus group a long way to go all the way from infinity to 1:1 magnification.... Second, most use "long throw" focus which emphasizes precision over speed, because shallow depth of field at higher magnifications can make focus accuracy very critical. The Tamron SP 60mm macro sells for about $525 new. I know that's almost double the price of the Nikkor 40mm micro, might be able to find the Tamron for a bit less used.
It is true that longer focal length macro lenses make for more working distance, which can be helpful at times with shy subjects. HOWEVER, the longest macro lenses (150, 180, 200mm) also make for extremely shallow depth of field AND are much harder to hold steady, more likely to require a tripod and less usable for hand held shooting. For both crop sensor and full frame, I recommend a macro lens in the 90, 100, 105mm range as more generally versatile choice. Crop sensor camera users might also consider 60, 70, 85mm macro lenses as more compact alternatives, but focal lengths shorter than those will be difficult to use in the field, leave too little working distance.