Remote triggering the Nikon D70

Introduction

This page describes modifications to the light-operated camera trigger that is described at : http://xray.bmc.uu.se/markh/cam_trig/cam_trig.html.

But if all you want is a wired remote control, then you can follow the instructions on this page, and replace the light trigger with a simple switch.

There are three issues when remotely triggering the Nikon D70 or D50 :

1) Triggering

To electronically trigger the camera, you must either send a complex signal to the USB port, or send an infra-red signal to the sensor on the camera. A simple and safe way to do the latter is to use the standard remote control device (ML-L3), and trigger this externally. Rather than tear open the remote control and try to modify the electronics, I made a very thin switch that can be inserted between the battery and its contact, and trigger this with the electronic switch (or a simple mechanical switch if all you want is a wired remote). This way the remote control can be used as normal by sliding the switch out again.

The switch is made from a small sheet of copper foil bought at a hobby shop or salvaged from some old electronic device. From this cut out a shape like a table-tennis bat, with the pad slightly smaller than the size of the remote battery, and the handle long enough to reach out of the remote control. Now solder a wire on to the end of the handle and insulate one side of the foil with tape. On top of this tape you need to fix another wire, which has the last few millimeters of insulation removed. You can fix either with glue or with another piece of tape that covers only part of the wire, with the uninsulated part sticking out over the insulated surface of the foil.
The idea is that you now have a sandwich that you can slide into the remote control on top of the battery, with the naked side of the copper foil facing up and the taped-on wire pressing against the negative surface of the battery. If the wires you use are thick, you may need to cut a nick in the battery holder in order to close it.

In order to trigger the camera, you must now both press the remote button, and short-circuit the two wires on your new switch, so if you put a small clamp on the original remote switch, you can trigger just by shorting the new one. If you are using my trigger, you achieve this by connecting the two new wires to a 3.5mm jack and plugging this into the trigger socket.

The following pictures may make things clearer :

2) Remote time-out

One of the few inexplicable design decisions on the D70 was to set the maximum attention span of the remote control system to 15 minutes. This means that if there has been no trigger within this time, the camera stops listening for a signal, and so for example to watch for animals breaking a light beam all night, you must keep the camera awake by triggering at least every 15 minutes. In order to do this, I have added an extra circuit to my box that adds the option of triggering the camera regularly up to a maximum of 13 minutes. This strobe setting can also be used for making time-lapse sequences. You can see the circuit diagram here.

An alternative way to use the D70 remote control as a simple cable release using fibre optic cable can be found at : Fibre optic cable and the D70 remote

3) Release lag

When using the IR remote release, I find that there is a delay of more than 100 ms before the shutter triggers, even with exposure and focussing set to manual. I've found no way around this problem, which excludes use of the laser trigger device for fast-moving insects with the D70. I'm not sure the wired release on the D70s will solve the problem either.

External links :
In case you can't afford $15 for the Nikon remote, here are a couple of thorough web pages on how to build your own :
http://www.bigmike.it/ircontrol
http://users.tkk.fi/~jwagner/electr/d70remote

(MRH homepage)