Author Topic: Micro Nikkor 105mm f/4 Ais CPU modifyed  (Read 5614 times)

Erik Lund

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Micro Nikkor 105mm f/4 Ais CPU modifyed
« on: June 10, 2015, 21:13:32 »
Before leaving for Slovenia I modified my Micro Nikkor 105mm f/4 Ais with a CPU from Bjørn.
I have been looking for this particuler lens for many years for a nice sample to appear that was not too abused, luck struck again and I now am the happy owner of a mint sample :)

It has performed admirably during the trip! both for close ups and for distant subjects!

And in IR

Here a three image stitch in IR

With a fill flash stopped well down

This is really a highly recommended way to get close ups of the best quality at a reasonable price.
Erik Lund

Roland Vink

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Re: Micro Nikkor 105mm f/4 Ais CPU modifyed
« Reply #1 on: June 11, 2015, 02:02:03 »
First post here! Nice to be back :-)

Lovely images, I particularly like the last one with the beetle.

The AIS version has the same optics as the AI and pre-AI versions, but the redesigned barrel is more slender with a much deeper built-in hood and a thumb screw to lock the focus ring. With only 5 elements in 3 groups there are very few glass-air boundaries to cause flare so contrast is excellent in spite of the older coatings. Vignetting wide open is the lowest of any lens I have. Unlike the later more sophisticated macro lenses it has no floating elements so it does not suffer from focal length shortening at close range, giving it much better working distance.

The AIS 105/4 was my first macro lens. Bought second hand it has served me well for many years - even after I bought the AF 105/2.8 micro. I don't have as much time for macro these days but it's a lens I'll always keep.

Bjørn Rørslett

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Re: Micro Nikkor 105mm f/4 Ais CPU modifyed
« Reply #2 on: June 11, 2015, 04:40:52 »
I have had , and used, several of the shorter 55 mm f/3.5 Micro-Nikkors before I finally landed on the 105/4. Initially as the precursor model, the 105/4 Bellows, then the 105/4 AI. It was my most frequently used lens from approx. 1980 to the  late 1990's. I especially favoured its dual use as a lens for details and landscapes.

The image is rich and mellow with beautifully rendered almost pastel-like colours. Whilst the bokeh is less soft than epected today, using it around its optimum performance peak f/5.6 to f/9 makes for clean and nice close-ups.

The working distance is much longer than most of the subsequent Micro-Nikkors, thanks to the unit focusing design. A PN-11 extends magnification from 1:2 up to 1:1 whilst keeping a long working distance, at the expense of a quite long physical package. You are well advised to mount the 105P + PN-11 on a tripod using the tripod collar of the extension tube.

Øivind Tøien

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Re: Micro Nikkor 105mm f/4 Ais CPU modifyed
« Reply #3 on: June 13, 2015, 03:34:00 »

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.

D200, f/8

D200, f/8

D5100, f/7.1

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:

D200, f/5.6, this and the next.

Even more cropped, same mosquito shortly after the frog dived:

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):

Øivind Tøien