Sunday, September 04, 2016

nikon nikkor AI-s 105mm lens manual focus but full automatic with a Dandelion chip

I modified a very old manual lens so that i can:
1 - use the flash with it.
2 - have automatic parameters selected by the camera for aperture and shutter priority.

The integration of the dandelion chip for nikon is easy on some lenses and requires some filing on others. The 105mm nikkor requires adaptation. see link.

inspired from

the procedure:
- look at another digital lens to see the positionning of the contacts relative to the mount.
- close the lens aperture to f/22 and put the Dandelion Chip on the lens back barrel and align the 4 th pin of the chip with the white/black dot on the lens. Mark the 4 th pin position on the barrel as well as the edges of the positionned chip. these marks will delimit the area to cut.
- remove the back barrel while on f/22. only 3 tiny philips screws. do not remove the smallest rotation  blocking screw that is in the mount rail.
-Place the barrel in a vise with wood jaws to hold it without damaging it.
- cut the barrel inside the marks you have done with a dremel or similar, do not cut too much as you can fine tune with files later.
- carefully adjust the hole with small files, careful as this is aluminium and it goes real fast. make sure the chip protrudes a little bit from the barrel, it is not obvious how much space is available for the contacts to happen with the camera. i have the chip's plastic protruding by 0.2-0.3 mm ish.
- when the 4 th pin of the dandelion aligns perfectly with the marks, you can use slow cure epoxy resin to glue it in place. i used steel reinforced resin as it is easy to adjust and the finish is dark grey.


Programming Dandelion for Nikon

Before you start

Set your camera to M exposition mode.
Programming of Dandelion includes three simple steps:

1. Activation of the program mode
2. Command input
3. Data input

First in the Menu, set the display/memo. exposition timing to the maximum for all the parameters as the programming of the dandelion chip takes time and you can not press any button other than the trigger during programming or it turns off programming mode.
remove and replace lens on camera again, then turn camera on. 
Activate Dandelion program mode by making 3 successive shots with the following shutter speed:
- 1 '' sec
- 6 '' sec
- 1 '' sec

Your screen will show aperture changing by itself in rounds:
2.8 - 4.5 - 5.6 - 10 - 20 - 40 - 90.
This means that Dandelion has entered program mode.
Commands are input with a 1 sec. shot when a certain aperture value appears on the screen.
You cannot choose an aperture value with a controller on your camera. You will have to wait until the needed aperture value appears on the screen. If you miss the value you need, you will have to choose it when it appears again during the next round.
If you don't make a shot after three rounds, Dandelion will exit program mode automatically. To force exit simply turn your camera off.

Changing aperture
Make one shot at aperture 2.8. Aperture will start changing in rounds, but this time from F1 to F90. Choose the value you need. You can only choose aperture values the camera displays. Make a shot at the value you need. Dandelion will memorize it and exit program mode.

Changing focal length
Make a shot at aperture value 4.5. The aperture will continue changing, this time from F1 to F90. Here each value corresponds to focal length according to the table:

Aper. Focal
Aper. Focal
Aper. Focal
Aper. Focal
Aper. Focal
1.0 5 mm
2.7 28 mm
6.3 68 mm
17 160 mm
40 400 mm
1.1 7 mm
2.8 30 mm
6.7 70 mm
18 180 mm
43 420 мм
1.2 8 mm
3.0 32 mm
7.1 75 mm
19 190 mm
45 450 mm
1.3 10 mm
3.2 35 mm
7.6 80 mm
20 200 mm
51 500 mm
1.4 12 mm
3.3 38 mm
8.0 85 mm
21 210 mm
54 550 mm
1.5 14 mm
3.5 40 mm
8.5 90 mm
22 220 mm
57 600 mm
1.6 15 mm
3.8 42 mm
9.0 95 mm
24 240 mm
60 650 mm
1.7 17 mm
4.0 45 mm
9.5 100 mm
25 250 mm
64 700 mm
1.8 18 mm
4.2 48 mm
10 105 mm
27 260 mm
68 800 mm
1.9 19 mm
4.5 50 mm
11 110 mm
29 270 mm
72 900 mm
2.0 20 mm
4.8 52 mm
12 120 mm
30 280 mm
76 1000 mm
2.1 21 mm
5.0 55 mm
13 130 mm
32 300 mm
81 1200 mm
2.2 22 mm
5.3 58 mm
14 135 mm
34 320 mm
85 1500 mm
2.4 24 mm
5.6 60 mm
15 140 mm
36 350 mm
90 2000 mm
2.5 25 mm
6.0 65 mm
16 150 mm
38 380 mm
Table 1. Aperture values and corresponding focal lengths.
Make a shot when the needed aperture value appears. Dandelion will memorize its corresponding focal length and exit program mode.

AF/MF switch
Works similar to lens switch. Simply make a shot when aperture value 5.6 appears and the focus mode will switch. Dandelion will then exit program mode.

Confirmation dot justification
You can move autofocus confirmation dot slightly forward or backward by experimentally moving justification constant. One shot at aperture value 10 moves the dot back. Aperture 20 moves the dot forward. The range consists of 17 positions. On default 9 (middle position) is used. Move the confirmation dot forward or backward and try to adjust sharpness. The best justification distance is 3-5 meters.
To exit justification mode turn your camera off.

Lens function
If Dandelion is installed on a lens with an automatic instant-return aperture of AI-S type, you will have to unblock the aperture control function by setting Dandelion to your lens's minimal aperture value which usually equals to 16 or 22.
For correct functioning of an instant-return aperture you will first have to set Dandelion to the fully-open aperture value. You can do this with the help of function 2.8. Then use the following function of minimal aperture value change.
Make one shot at aperture value 40. Aperture will start changing its values round by round, from F1 to F90. Choose the value you need. Normally it will be 16 or 22.
Make one shot when the aperture value you need appears. Dandelion will memorize it and exit program mode.
After that you will be able to work with your aperture in the same way as with an AF lens. Close the aperture on your lens, thus setting it to its minimum. Let it stay that way forever. Then you can choose aperture value, adjust sharpness, make shots, etc, with your main dial.
Note: In pre-AIS series lenses manufactured before 1981 the aperture control mechanism has a non-linear construction. When making pictures with such lens a slight expo correction may be needed.
AI-S lenses with linear aperture of the new type can be distinguished by a special marking: minimal aperture value is marked in red on the main and additional scales. Additional information and photos can be found here.
New AI-S series includes Samyang and Zeiss ZF lenses.

Reset default settings
Make a shot when aperture value 90 appears. Dandelion will reset its default settings (45/2.8, AF, justification 9) and exit program mode.
When finished set the display timing menu back to desired.


Which lens?

(from :

Update 2-March-2012: list of lenses and adapters successfully converted with 'Dandelion' AF metering chips. Unless indicated otherwise lenses are Nikkors.
[g] means gluing only required, [m] means machining needed, (1),(2),... are the references below. Note that there is some contradictory information for a few lenses.

15/3.5 AIS [g] (18)
18/3.5 AIS [g] (18)
20/3.5 AIS [g] (2)
20/2.8 AIS [g] (18)
24/2.0 AIS [g] (4,18)
24/2.8 N.C. [g] +AI conversion (5,13)
24/2.8 AIS [g] (14,15,18)
25-50/4.0 AIS [g] (18)
28/2.0 AIS [g] (3,18)
28/2.5 AIS (14)
28/2.8 AIS [g] (2,14,18)
28/2.8 E (silver ring) [g] (18)
35/1.4 AI [m] (9)
35/1.4 AIS [m] (18)
35/2.0 AIS [g] shim, but no machining (1,18)
35/2.0 [m] (8)
35/2.8 AIS [g] glue+radial shim (5,13,18)
35-70/3.5 AI [g] (18)
35-70/3.5 AIS [m] (18)
35-70/3.3-3.5 AIS [m] (18)
35-70/3.5-4.8 AIS [m] (18)
35-105/3.5-4.5 AIS [g] (18)
35-135/3.5-4.5 AIS [m] (18)
36-72/3.5 E [g] (18)
50/1.2 AIS [m] (16)
50/1.4 AIS [g] (5,13)
50/1.4 AIS [m] (18)
50/1.8 AIS [m] (2,18)
50/1.8 AIS 'Japan' (S/N 20.. to 22.. - 'pancake'(?)) [g] (18)
50/1.8 E (no silver ring) [g] (18)
50/1.8 E (silver ring) [m] (18)
55/2.8 macro {micro?} [g] (8)
55/2.8 micro [g] (14)
55/2.8 micro AIS [g] (18)
55/3.5 Micro-Nikkor [g] +AI conversion (9,14)
75-150/3.5 E [m] (2,11,18)
80-200/4.0 AIS [m] (18)
85/1.4 AIS [m] (17,18)
85/2.0 AIS [g] (4,18)
85/2.0 [g] (8)
100/2.8 E [m] (1,2)
100/2.8 E (no silver ring) [g] (18)
100-300/5.6 AIS [m] (18)
105/1.8 AIS [m] (11,18)
105/2.5 AIS [m] (5,8,13,14,18)
105/2.5 'P' AI'ed [g] (14)
105/2.8 micro AIS [g] (3)
105/2.8 micro AIS [m] (18)
105/4.0 micro AI [m] (15)
105/4.0 micro AIS [m] (18)
135/2.0 AIS [m] (18)
135/2.8 AIS [m] (5,13,18)
135/2.8 'Q' AI'ed [g] (14)
180/2.8 AIS [m] (18)
180/2.8 ED AIS [m] (15)
200/4.0 AIS [m] (5,13,18)
200/4.0 micro AI [g] (15)
200/4.0 micro AIS [m] (18)
300/2.8 AI [m] (18)
300/2.8 ED-IF AIs [g] (15)
300/4.5 AI [m] (5,13,18)
300/4.5 'H' AI'ed [g] (14)
300/4.5 ED-IF AIs [g] (15)
generic T-mount adapter (1)
Vivitar 2x macro focusing TC (AIS) (7)
Samyang 14/2.8 ED AS IF UMC [m] (18)
Tokina 24/2.8 (AI-S) [g] (18) ('after removal of slightly prominent screw on black ring')
Mir 35/2.0 'MIR 24-H' [g] (4)
Zeiss 35/2.0 ZF 35mm f.2.0 Zeiss [m] (6)
Angenieux 70-210 [m] (8)
Kiron 105/2.8 Macro (AI-S) [m] (18)

1) 'jl22182': "I've used these chips on a 100E f/2.8, a 35 f/2 and a generic T-mount adapter." (same thread as ref.2)
"AI-S Nikon 35 f/2. Bit of a tedious process as I had to shim the chip to get the contacts in the right position, but not really difficult. No surgery was necessary on the lens." (different thread)
2)'Jpig': "I have chipped the following lenses and use them on a D40: 20mm 3.5 AIS, 28mm 2.8 AIS, 50mm 1.8 AIS, 100mm 2.8 E, 75-150mm 3.5 E. The 20mm and 28mm were easy and only needed to have the chip glued on. The others required some cutting to make room for the chip. "
pics (axial view of mount):
3) 'Alain x': "The only lenses I own that did not require any cutting are AIS 28mm/2 and Micro AIS 105mm/2,8. I installed the chip on the 28mm/2, and am happy with the result."
4) 'chimpden' - 11/16/2010 : "I've chipped 3 lenses for use with my D90: Nikon 24mm F2 AI-s, Nikon 85mm F2 AI-s, and a Mir 24-H (35mm F2 Russian lens in Nikon mount). They were all quite easy to do as the geometry of their mounts was a perfect for the Dandelion without any modifications at all - just glue and go."
5) 'Toby' NYC - 1/14/2011 : "This is my install of the "dandelion" chip on a Nikkor 105mm f2.5 AI-s lens. The install involved taking the mount apart and machining a piece of the mount center. The dandelion chip is epoxied to the mount center.
So far I've chipped the following Nikkors, 24mm f2.8 N.C. (along with converting it to AI) , a 50mm f1.4 AI-s, and a 35mm f2.8 AI-s."
one pic in
Pictures of more chipped Nikkors: and ref.13 below.
lenses: machining: 105/2.5 AIS , 300/4.5 AI, 200/4 AIS, 135/2.8 AIS,
just glue: 50/1.4 AIS, 35/2.8 AIS (glue+radial shim), 24/2.8 NC,
6) Livio Spallone - 7/1/2010 : "This morning the chip arrived and i installed it: 20 minutes work , one small cutter, one screwdriver, black epoxy glue. Some things to know:
Zeiss made the bayonet ready for chipping ( two holes and screws already in the right place) but waited three years before coming out with the .2 version : they really SHOULD offer an upgrade part (black plastic lens "bottom" with chip installed). Installing requires good hands but ZF 35mm f.2.0 was easy to modify. ... Note the holes and the screws , unused in this series, to chip the lens Nikon style (chip screwed to the lens bayonet mount). Chip so small it goes out of the metal lens mount, cut the plastic "bottom" cover of the lens."
one pic in
7) Sem Svizec , Nov 14, 2011; 10:44 a.m. : "I got my $30 Dandelion from tagotech and have successfuly epoxied it to an AI-s Vivitar 2x macro focusing TC."
8) Laurent Schuler , Nov 16, 2011; 06:10 a.m. : "I made the conversion with a dandelion chip on following lenses :
55 /2.8 macro
85/2 On thoses two lens, there was no need to plane the lensbarrel.
On the 105 /2.5, 35/2, and angénieux 70-210, I had to plane the lensbarrel (There is a kind of black wall that has to be planed in order to place the chip in the right position."
9) Stefan Gruenendahl , Feb 1, 2012 and Feb 4, 2012
10) Pic showing Nikon chip circuits and connectors, taller than dandelion:
11) 'Rodeo Joe' , Nov 26, 2011
12) Checking AI aperture nonlinearity, from a Sep. 2004 post by 'Ro Ro' in :
"Another thing: I had to adjust the aperture lever inside the lens to get correct apertures. This is easy to check: Set the camera to a known aperture and then press the DOF button and hold it. When you then rotate the aperture ring from 22 to open aperture the blades should start moving when the aperture values match."
13) Dpreview thread on chipping with posts by 'Toby NYC' (chipping w/ pics), 'Kent J' (AI aperture response) and Joseph S Wisniewski (aperture control, chip interaction with AF): ;see also ref. 5.
14) More chipped lenses (some done by, but with integrated chips) at :
15) David L. et al., Dec. 2010:
16) 50/1.2 (janiksela - 10/29/2010) : ""Where did you remove material from in order to get the chip in; from the side of the rear element or the back side of the chip?"-- from the side of the rear element and a little bit of the chip." ( (with pictures, unfortunately not showing the modification to the rear element)
17) 85/1.4 AIS, SG Feb.2012: . Clearances are a bit tight, but it's doable.
18) (in german) contains a long list of chipped Nikkors (and a few others).
Stefan Gruenendahl , Mar 06, 2012; 05:32 p.m.
Update for the 50/1.2 AIS reference:
16) 50/1.2 (Sami Jänikselä - 10/29/2010) : See, and for a picture of the modification to the rear cell.
reg eggen , Apr 27, 2013; 02:14 p.m.
20/3.5 AI conversion (g)
85/1.8 AI conversion (g)
135/3.5 AI (m) EV unstable in 'G' mode. After toggle control option '60' stable but EV +1.5 overall.
300/4.5 AI conversion (g) must check EV in 'G' mode
MC Zenitar 16/2.8 AIS (m) small piece of (plastic) black protection plate must be removed.
reg eggen , Apr 27, 2013; 02:37 p.m.
Has anybody made an EV/aperture comparison between before and after chipping an AI (converted).
I've noticed that the 135/3.5 AI I've chipped needs a EV+1.5 correction compared to the lens before it was chipped (used as a "Non CPU lens" on my D700).
Both using the aperture ring on the lens to set the aperture value, NOT the dialcontrol on the camera (I allmost allways work in A mode).
And if so, did you find a permanent solution for this EV deviation? Meaning without a manual correction on the camera, which I usually forget ;-)

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