my Nikon 105 macro can be slow in focusing and searches a while, however in some instances it focuses very quickly. What I have described is when I am shooting my D 90 in Aperture priority. Does this sound about right for this lens? thank you joanlvh

It's a known hunter while focusing at times.

you can put it on limit which helps in some situations.

Yes, and so does the old 60 sometimes.

EBH

Series D or G?
The older D series is a known 'terrorist' when it comes to hunting. . . .
but the newer VR model was reportedly/supposedly much better in this respect?
What are you trying to focus on? The micros like a lot of contrast to 'look' at...
Bruce

If shooting macro, forget about autofocus. It is quicker to manual focus and shoot thrice.

My 105VR is very hit and miss with subjects less than a metre away. Beyond 800mm no problem. Apparently very common with Micro/macro lenses.

Something not mentioned yet - lenses which focus very close tend to focus faster near infinity, and much slower near minimum focus.
This is because most of the focus ring travel (and most of the AF motor work) takes place at closer focus distances.
Taking the 105 macro D as an example the focus ring travel between 1 foot and 9 inches is about 5 times greater than between infinity and 3 feet.