I'm a Nikon user and have had trouble for some time getting my various Nikon bodies to trigger remotely reliably using a remote 10 pin connector/cable. I've fiddled with all sorts of things to try and get this work, and usually had some success, but not sure "exactly" why. Since I was buried in other things once I got it work OK, I just kept doing the same things/sequence/setup, not thinking about why this was behaving the way it was.
Recently I've been creating a complex fully automated DIY Stack and Stitch system (It's running as I write this creating a 9 stack session with ~300 images) and ran across this old Nikon remote interface problem again. To add insult to injury the 2.5mm female socket connector I am using doesn't make contact with the middle center section of the 2.5mm plug!!
So I was having a devil of a time trying to collect some test images when using LV and Nikon's totally silent shutter mode (EFCS & ESCS). I could get the camera to trigger with regular shutter, but it would block out LV, and lots of other strange behavior. I do have a old cheap remote I modified 10 years ago with a Schottky diode between some pins and has a single contact 3.5mm male connector and RCA male plug for the Stackshot controller. This works fine with any camera body and setup, but I wanted to use the eBay Nikon 10 pin to 2.5mm type connectors and connect to my S&S system with the 2.5mm connectors. Here's where I found the 2.5mm sockets I have don't make contact with the center middle plug, even though they have separate connection for this!!
I opened the old remote to see how the mechanical push button works. When pushed the equivalent 2.5mm center middle pin is shorted to ground, then the plug tip equivalent is shorted to ground. This is probably to allow AF when partially pushed, and take the image when fully pushed.
With this in mind I've added a second optical coupler to handle the two pins, with the 1st coupler being used for the plug middle pin and the 2nd for the plug tip. I staggered the optical trigger signals by using the Raspberry Pi GPIO (S&S Controller) pin for the LED indicator to drive the second optical coupler. This works nicely since the small delay between the two couplers is naturally created by the sequential software commands to the GPIO ports. All the Nikon modes work now as expected without any fiddling with my various camera bodies.
Anyway, I'm sure many of you already knew this, so sorry for bandwidth use, but figured a couple folks might not and be struggling with Nikon's interface as I have for longer than I care to remember!!
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