Ever thought that it would be great if your Nikon D40/D90 could meter with an old AI lens?
So far this was only possible using a D200/300 or better. But with the programmable Russian Dandelion chip every Nikon DSLR body will be able to meter with these old lenses.
This is what you’ll need:
These are the instructions for the 2/28 AI-S. While most Nikkors are almost identical, others might differ slightly. I advise you to take a picture before every step you take, this might be a big help when you put things back together…
Remove the three black screws that are marked with a red circle in the image.
If there are no black screws on top, you’ll find three silver screws on the side of the bayonet, holding the black ring. Actually, you’ll find four screws. Three will be identical in size and form and one will be different. The three that are the same are sunk in the bayonet and you need to remove them to get the black ring loose. The fourth screw is smaller and is not sunk in the bayonet. Don’t remove this one, as it holds a spring to pull back the aperture inside the bayonet.
Remove the black ring and the three screws that hold the bayonet.
Remove the bayonet, and place the lens cap on the lens for protection.
File as much off the the black ring as you need in order to properly place the chip on it. To get an idea where you need to file, have a quick look at the picture of step six.
With some lenses you will need to file a lot. A metal saw might become very handy…
Put the black ring with all the screws back on the silver bayonet. Place the white caliper on the bayonet, the yellow dot needs to be over gap.
Now you need to glue the chip to the lens. The blue part of the caliper is where the chip goes. It’s not symmetric, and the right side of it will be the side of the chip with only one pin.
If you slightly misplace the caliper, that the flap in the upper red circle is a bit closer to the center than it should be, you’ll have enough space to place the chip between the caliper and the lens. Once you put the chip with glue on it in place, push the caliper in its intended position, centered on the bayonet, in order to make sure that the chip is in the right place.
Let the glue dry before you proceed.
Put the bayonet with the black ring and the chip back on the lens.
The “U” on the bayonet needs to be placed over the silver pin in the lens.
Don’t forget the screws that hold the bayonet…
This is what it looks like when it’s done:
Now the only thing left is to program the chip. Instructions can be found here.
It proved to be useful to turn off the image review and extend the Auto off timer for the menu.
You’ll need to close the aperture of the lens (f/16 or 22) to work properly in A, M and S mode. Once you’ve done this, the aperture is controlled by the camera, and there is no need to change anything on the lens any more.
Hope this is helpful. If you have any questions, don’t hesitate to ask them in the comments.
P.S.: Here is a quick test shot. The picture was taken with a D40, Nikkor 2/28 AI-S and the built-in flash. The camera was used in A-mode, while the flash was set to TTL: