The 105mm f/4 AIS micro is one of the first lenses I chipped with Bjørn's custom chip together with the PN-11 that came with it. While not providing as soft background rendering as the 105/2.5, I really like playing with how it paints the background.
![](http://otoien.zenfolio.com/img/s9/v93/p1244074423.jpg)
D200, f/8
![](http://otoien.zenfolio.com/img/s8/v81/p1244074279.jpg)
D200, f/8
![](http://otoien.zenfolio.com/img/s5/v132/p1244062581.jpg)
D5100, f/7.1
![](http://otoien.zenfolio.com/img/s9/v86/p1244062611.jpg)
D5100, f/7.1
How much blood loss can a wood frog endure? A pretty strong crop; shutter speed was a bit on the long side for hand-holding:
![](http://otoien.zenfolio.com/img/s10/v114/p1244074239.jpg)
D200, f/5.6, this and the next.
Even more cropped, same mosquito shortly after the frog dived:
![](http://otoien.zenfolio.com/img/s12/v173/p1244074260.jpg)
Admittedly, because of the size compared to the 105/2.5 and the better balance of that lens on the lightweight D5100, I rarely take it on longer travel. It probably deserves to be used more.
As noted, it renders well in IR without a hotspot. It requires a slight twist of the focus ring towards closer range after sharp focus on my D40x IR-720nm which has Lifepixel standard calibration (carpenter ants at the cabin I live in, more of a technical image):
![](http://otoien.zenfolio.com/img/s5/v116/p1244076827.jpg)