Nikon SB-28 fires only at the second frame

[lynxlynx.ch]

Dear all,

I'm a camera trap newbie and just bought me some material to create a DSLR camera trap:

Pelican Housing
Nikon D5500
Nikon AF 20 mm D 2.8 lens
2 Nikon SB-28
Pixel TF-322
PC Sync cable
Trailmaster TM-550

The whole setup is working except for the Nikon SB-28, i set them to standby mode but when the trailmaster triggers the camera the SB-28 wakes up at the first frame and fires only at the second frame. I haven't found out yet, how to solve this problem. When i put the Nikon SB-28 on the Nikon D5500 directly it fires at the first frame, and also when i put the Pixel TF-322 on the hotshoe. I guess the problem must be between Pixel - PC Sync cable and Nikon Flash. Is it possible that this scenario doesn't work with the PC Sync cable ? Only with the Nikon SC-26. Do i need some other Hot Shoe Adapter ?
Does anyone have this setup with Pixel TF-322, PC Sync cable and Nikon SB-28 ?

Thank you very much for your feedback.

kind regards

Lars

[-jeff]

Hi.....welcome to the forum.

The SB28 and other SB series of Nikon flashes make wonderful camera trap flashes. The sleep mode and quick wake up make it a natural for camera trapping.

There are two ways to remotely wake a SB28. One is with the PC port in the flash. The problem with this method is the first flash trigger wakes the flash and the second triggers the flash. Not exactly ideal for camera trapping. You either end up with a shot of the animal looking at the camera or the backside of the animal as it was spooked by the noise of the camera shutter.

The second method is providing the flash with a wake up signal when the camera shutter button is pressed half way down. On Nikon and Canon cameras there is a pin on the camera hotshoe that goes positive when the camera shutter button is pressed half way down. A wire needs to be run from this pin to the corresponding pin on the flash shoe.

There are a few wireless flash triggers out there that provide the wake signal. I have been using the Phottix Strato II with success. This is a really easy way to trigger multiple flashes.

If you are a "do it yourself" type, you can make your own cable. If not then there are some off the shelf commercial cables out there. Or you can have the guys at TRLcam.com build a custom cable for you.

Here are a couple wiring diagrams showing the connections between the camera and flash. One diagram for a single flash and one for multi flashes. Both diagrams are non-TTL.

When the shutter button is pressed halfway down, a voltage of about 3 volts is sent down the wake pin. This small voltage wakes the flash. When the shutter button is pressed all the way down, the flash fire pin is pulled to ground causing the flash to fire. The diodes are in the circuit to isolate the flashes from each other.

20181015120415-320bc7c2-me.jpg

20181015120411-c6afdc9b-me.jpg

Hope this helps. Good luck in your camera trap project and post the results here.

[lynxlynx.ch]

Dear Jeff,

Thank you very much for your helpful information. I didn't knew that.
I always thought i am doing something wrong :-)
OK. I have thought that a wireless solution could be less reliable than a wired one because more batteries, that could fail... but that could be a good solution for me to. On the other hand i am a bit of a "do it yourself" type and i guess i'll try to make my own cable.

Thank you very much, now i know how to go forward with this project and i'm happy to post the results here !

kind regards from Switzerland

Lars

[-jeff]

If you have two Pixel TF-322, you can take them apart and solder to the three pins you need to trigger the flash.

Here is a diagram of the hotshoe. The connections you want are Ground, Data (Q) and Handshake (SP). The Handshake pin goes high when the shutter button is pressed half way down and wakes the flash.


20151231113200-a5e4ba3d.jpg

One hint, do not apply heat too long to the pins while soldering. The pin will melt the plastic around it and the pin will be easily pressed through the plastic housing.

[lynxlynx.ch]

Dear Jeff,

Yes, i have more than two Pixel TF-322

That's really great ! Thank you very much :-)
I'll try that at the weekend

kind regards
Lars

[ArthurV]

That is some valuable information, Jeff.

[lynxlynx.ch]

I tried to follow your instructions, but unfortunately i couldn't fix this issue. I guess i did something wrong. That's why i created a visualisation

Pixel TF-322 Modification.JPG

On the left side is the original cabeling from the Pixel TF-322. Only X-Sync and Ground are connected to the PC Sync Port.
I soldered the Handshake & Data to the Ground Connection of the PC Sync Port. It is still working but always only from the second trigger. What am i missing ? Or what did i wrong ?
Maybe the chaining of my 2 Nikon SB-28 is wrong ? That's why i created a schematic for it...

DSLR Camera trap schematic.jpg

Any ideas ?

thank you very much !

Kind regards

Lars

[-jeff]

Ok, if I am reading your diagram correctly, you are still using the PC Sync connection? If so, that will not work. To wake and fire the flashes requires three connections and three conductors. The PC Sync connector only has two.

Maybe this image of the inside of the TF-322 will help.

20180521100310-352d7587-me.jpg

Connections:

Ground - Self explainitory

Flash Wake - When the camera shutter button is pressed half way down, the camera sends a positive voltage (about +2 volts) to this pin on the hot shoe to wake the flash.

Flash Fire - This connection on the hot shoe is pulled to ground by the camera when the shutter button is pressed all the way down and causes the flash to fire if awake. If the flash is not awake, the first shutter activation will wake the flash and the second will fire the flash.

I usually remove the PC-Sync connector on the TF-322 and run my three conductor wire through the hole. Then when done, use a little hot glue to hold the wire stationary so the soldered connections do not break free.

Also, notice on the TF-322 the ground connection is very close to the wake pin. This is a common problem with the TF-322. It will sometimes short the wake pin to ground and cause the flash to not wake.

[lynxlynx.ch]

OK. i think now i understood. thank you very much. So i need to organise another cable for using it on the other port of the flash. because i only have pc port cables ;-)

[-jeff]

That is correct. You need three conductors. I typically use Belden 8451 for flash cables. It has a UV stabilized outer sheath and remains somewhat flexible in cold temperatures.