In the high end digital cameras Canon decided to use a special connector for the remote instead of the widely available 2,5mm micro-jack connector used in their other cameras and also used by Pentax.
Not happy with this decision, they decided they would use a proprietary connector and invented the N3 connector. The bad news is you can't buy this connector anywhere for your own remote control projects, so your options are to buy a cheap remote or extension cord and chop the connector or to build your own connector.
The first option is the easy one, but the second is the funny one :-)
Step 1: Getting the Measures
If you, like me, want to build a N3 replica connector, you need to know the measures of it. I googled all the web searching for the technical data, but couldn't find it anywhere, so I decided to research it by myself.
In the first picture you can see the measures of the connector and in the second one its depths.
Step 2: Finding the Right Connector
With the measures I took I headed to the Radio Shack and after a lot of searching I finally found a connector that fits the N3 although it will need a little of adjustment.
The part is the mini XLR 3 pin connector. We only need the little piece with the pin holes and the metal struts and we can discard everything else (or save it for another project!).
Step 3: Comparision and Cutting Plastic Away
Here is a picture of the mini XLR compared to the N3 connector measures.
The fit of the pins is perfect but the plastic encapsulation needs a bit of sanding to fit the N3 cup.
you have to flat cut the top and the bottom of the circle as shown in the image, then cut a round shape in one side and reduce a little the bottom curve in both sides.
To cut the round shape I used a Dremel tool with a small cylinder file. Instead of going straight to the cut measures, it is better to go slowly and trying the piece in the N3 connector. We want it to fit correctly and not get loose because of cutting too much.
Step 4: The Final Product
I made this project long time ago as you can see by the year in the schematics so I'm afraid I don't have pictures of the process of constructing the cable but it is quite simple. You solder a 3 wire cable to the pins in a 90º position pointing down from the camera and then you can encapsulate everything with hot glue or resin glue. The plastic piece you see in the pictures is part of an old PC keyboard connector. I cut it in half, removed the insides and adapted it to the mini XLR + cable assemble and filled the inside with 2 component resin.
Step 5: Using It As an Adaptor
The main objective of this instructable is to show you how to fit the mini XLR connector with the Canon N3 connector. The applications you can give to it are up to you. You can use it to interface with a computer to make automatic shooting, a timer, some trigger to shoot a very fast event... anything that can trigger the autofocus and shoot functions of the camera.
The first image shows the pin out of the connector. connecting the "Focus" pin with the "GND" pin will activate the autofocus and connecting the "Shoot" pin with the "GND" pin will shoot a picture. It is just like the shutter button in the camera. The light press is "Focus" and the deep press is "Shoot".
I used it to create an adaptor for the more common 2.5mm micro-jack connector. This is just a standard stereo micro-jack connector used by many brands of cameras and even not so high end Canon cameras (EOS XXXD, XXXXD, 60D, 70D...). At the time of doing this I had an old EOS 10D and a micro-jack remote control so I needed this adaptor.
So at the other end of the cable I soldered a female micro-jack connector where to insert the male micro-jack connector from the remote. If you also want to build this adaptor, the second picture shows the equivalent pin out of the 2.5 micro-jack connector.