Coolpix 950 / 990 / 995 Flash-adapter

This adapter allows the safe connection of non-Nikon strobes to the Coolpix 9xx digital cameras.

The Coolpix 9xx series are some of the best digital cameras on the market especially the 990.
However the internal flash is too close to the lens which results in red eyes in all portrait shots.
The internal flash also drains the camera batteries and extends the time until the camera is ready after each shot.
Therefore an external flash is one of the most useful accessories.
It is good that Nikon added a connector for an external flash even though they used a Nikon flash connector in lieu of a hot shoe.
They recommend to use the $$ Nikon-flash cable and the $$ Nikon-flash adapter to mount a $$ Nikon flash.
Any other flash can damage the camera and such damage is not covered by warranty.

If you are using a Nikon flash or another flash whose sync voltage doesn't exceed 6 Volts you probably will not need an adapter.
I use the Canon Speedlite 300TL that came with my T90 which I connect directly.
The Speedlite 300TL is powerful, is power adjustable and has a zoom reflector, and its sync voltage is only 3.5 Volts. which makes it an ideal companion for the Coolpix.
I don't use the TTL functionality but I am planning to use it as soon as I know hoe the Speedlite's interface works. If you know please send me an e-mail.

The adapter works with any Strobe:

See my Flash list and Kevin Bjorke's Flash list"

The coolpix flash socket:

Nikon uses a special connector for the eternal flash socket.
Until someone cones up with a compatible plug you'll have to buy an original $$ flash cable.
All Nikon flash cables that I have seen so far had a white and a red wire and a shield inside.
The shield is the ground (common) conductor.
The white wire is the flash trigger.
The red wire is the quench trigger.
Both outputs seem to be made with some sort of low voltage triac.
They are bipolar and will not switch off if there is too much current flowing.
Therefore it is recommended to always have a (100nF || 1MOhm) filter in series with the outputs.
Nikon claims that the max. Voltage allowed at the output is 5V.

The adapter:

You will need a Nikon SC-18 (or similar) flash cable, because the connector is not available anywhere.
Cut the cable in two pieces (and use the second half to build an adapter for a friend).

The pinout of the connector like this:

The circuit:

This adapter is a relative of my SX-70 flash adapter.

Circuit Description

Input section

A Lithium cell provides power for the camera side circuitry. Anything in between 3 and 5V will do.
A button cell with soldering contacts will last a long time.

R1 / C1 is a high pass filter. The coolpix output seems to be some kind of thyristor output.
Without this filter, the dc current will keep the output active until the adapter is disconnected.

R2 limits the current through the LED of the coupler. A miniature 3V Light bulb does also work.

High Voltage Output Section

For Strobes with a trigger voltage of 25 V or more:
The optocoupler is one with a Triac output, MOC 3021 (Motorola) or similar.
R3 / C3 form a high pass filter that prevents a steady current which might keep the triac open.

Low Voltage Output Section

For Strobes with a trigger voltage of less than 25 V:
This version uses an ordinary transistor-output coupler. These are directional, The bridge rectifier makes sure the polarity is correct.

I am not selling these adapters, mainly because I can't get those Nikon connectors, and Nikon wants 60$ for one cable (which they have probably manufactured somewhere in the third world for 20 cents a piece).

If you have any questions please send me an email

Quinton Marais has built a (low voltage) adapter to connect a Metz CL45 flash to his Coolpix 990

He sent me a photo and the circuit diagram of it