Help with Canon camera - lens and flash being temperamental!

I’m looking for some help with 2 camera problems. I’ve used the same set up for some time but have recently had a few issues - I haven’t been diving for some time due to Covid restrictions, but don’t remember these occurring before.

I’m using a Canon 700D in a Nauticam housing with the Tokina 10-17mm fisheye, or a Canon 60mm macro. I’m then using an Inon S2000 strobe using a fibre-optic connection, usually on TTL. I usually shoot with the camera on manual mode.

The issues are

1. A repeated error where the Tokina lens won’t communicate with the camera. I can’t reproduce this outside the housing, so I’m wondering if the focus gear may be causing some sort of traction on the connection during the dive?
2. Pre-flash not firing - resulting in the Inon strobe then not firing. Seems unpredictable, I assume this is a camera issue not a strobe issue.

Any thoughts or suggestions? I have an upcoming live aboard trip and I’d like to figure these out before I go!

For a communication problem with a lens I would first try cleaning the contacts.  Is there any movement in the the lens mount that could cause loss of contact?  Can you reproduce it in the housing but on land?  If you can reproduce this way it will likely be easier to troubleshoot.  You could try to seeing if it only occurs after zooming for example.  Do you have another camera body you can try the lens on? 

The pre-flash not firing certainly seems like a camera problem - what are you triggering the strobe with - the onboard flash or a flash trigger?

I assume you've confirmed it is the pre-flash not firing as opposed to the S2000 not detecting the pre flash.  The pre-flash is difficult to separate from the main flash as they occur very close together.  You can separate them if you put the flash into rear curtain sync and shoot at a slow shutter speed.  The pre-flash then fires at the start of the exposure and the main flash at the end if the shutter speed is in the 1/4 - 1 sec range or so you can clearly see both flashes. 

As a workaround you could always switch to manual flash - it's not that hard for most types of photos. 

1 hour ago, ChrisRoss said:

For a communication problem with a lens I would first try cleaning the contacts

Thanks - have tried that and it didn’t seem to help. My next step for testing is to put the camera in the housing on land as you say. I also have a 650D so using that is certainly an option.

I’ll take a look at the options you’ve described for the flash problem - I’m not very tech savvy but will do my best to play with the settings etc!

Thanks for the quick reply!