Backscatter MiniFlash Not Syncing

After way too long out of the water, I got all my photo gear out today to experiment in preparation to traveling to Fiji in 3 weeks.  I have a never-used Backscatter MF-1 that I've never used with my system.  I'm shooting a Nikon D850 in a Nauticam housing with a 26308 TTL Converter for Nikon along with a brand new Nauticam fiberoptic cable.  The flash trigger does cause the MF-1 to fire, however the MF-1 isn't syncing with the camera (all images are without flash exposure).

I'm stumped as to what the issue is or how to solve it.  Advice please!

Stewart

Sounds like it's firing on the pre-flash, then skipping the main flash. MF-1 is supposed to auto-learn the camera's pre-flash pattern, but perhaps it's failing in your case for some reason? Try setting the converter to mode 0 on the rotary dial, which disables TTL entirely. Don't forget to turn off the MF-1 and turn it back on afterwards, so that it resets whatever it is that it's learned.

A number of possible causes.  The camera/TTL converter and the flash need to have compatible settings as the flash doesn't communicate with the camera so doesn't know what the camera is set to.  The Backscatter flash handles this using a test shot to work out how many flashes the camera uses. 

It sounds like the camera/trigger is putting out a pre flash as the main flash would fire at the right time to sync if it was only putting out a single flash.  I don't believe the MF-1 is TTL capable so you will need to adjust your settings on camera to manual flash.

Another thing that might happen is if there is a pre and main flash from the camera/trigger if the MF-1 is at full power it will deplete the capacitor and won't be able to fire the main flash.

Turning off means doing the 5 button press thing not turning to standby.

5 hours ago, eyeguy said:

.... Nauticam housing with a 26308 TTL Converter .....

MF-1 requires a single strong pulse for synchronization. You have to switch #26308 control system to "M mode without pre-flashes". There are 2 available simple ways:

1)  Using camera menu, - set flash "sync speed" menu option "Auto-FP".

2) Using TTL-converter onboard rotary switch, - set it to "0" position.

All available ways for M mode setting are described in TTL-Converter #26308 User Manual.

Thanks for the quick replies guys!

I tried using the camera menu to set flash sync speed menu option to "Auto-FP" but I still wasn't getting it to sync.  I'll work on that further as this would be the preferred method since I can do this on the fly underwater if I wanted to.  However, I'm not clear on why this mode would give just one strong pulse from the TTL converter.  I understand the principle of Auto-FP for high speed sync with compatible strobes, but how does this work with a manual strobe.  Can you explain?

Using the TTL-converter rotary switch set to "0" solves the issue though!

If I'm taking the snoot down I'm dedicated to using it for the entire dive anyway (and regardless I rarely use TTL) so having the converter dial set to "0" isn't the end of the world, it just means I'll have to remember to change it to "1" if I ever thought I was going to shoot TTL on a dive.  I do like TTL for controlling exposure of manta bellies...I KNOW I'll be cursing myself one day when I've forgotten to switch it!!

14 hours ago, eyeguy said:

I tried using the camera menu to set flash sync speed menu option to "Auto-FP" but I still wasn't getting it to sync. 

Hi Stewart,

By the way, did you look at the User Manual, i mentioned above? There written the details about switching to M modes in that system.  If you use method of menu assigned command ("Auto FP" switches to M mode),  you also recommended to set camera menu "Flash Exposure compensation" to maximum value (+3 ev). This way the Converter issues a single pulse of maximum intensity. The same effect gives the position "0" of rotary switch. Maximum intensity pulse is important for MF-1 low sensitivity input control. 

      Fiber optical cable must be 613-core only. This is important here, because it has transmission index few times better than previous type cables. Nauticam sells new 613-core cables #26216 and #26217, but old type Nauticam cables are also available on the market. You have to check your cable model number, to be sure that it is 613 type optical core.  Also, try to connect the strobe by another cable (if you have 2 cables), because fiber optical cables sometimes have partially defected core treads inside the cover.

    Also, i can check if your version #26308 board hardwire is up to date for MF-1 support. Send me a macro photo of your board. Because MF-1 is supported by that board of latest version.

6 hours ago, Pavel Kolpakov said:

If you use method of menu assigned command ("Auto FP" switches to M mode),  you also recommended to set camera menu "Flash Exposure compensation" to maximum value (+3 ev). This way the Converter issues a single pulse of maximum intensity. The same effect gives the position "0" of rotary switch. Maximum intensity pulse is important for MF-1 low sensitivity input control.

Extremely helpful Pavel, thank you!  I am using brand new Nauticam 613-core cables  (#26216).  Yes I did re-read the manual with particular attention to the section on Controlled Manual Mode where AutoFP is referenced.  I did see where you can make ev adjustments but don't see where it recommended to set it at +3 ev.  However your explanation makes perfect sense and I will give that a try!  I'll send a picture of the board I have if this doesn't work.  Off to work today so it'll be a bit before I can play with the strobe again.

Thanks again,

Stewart

From the manual:  

Pavel,

I had the opportunity tonight to try the MF-1 with the camera set to Auto FP and the flash compensation set to +1 ev.  If fired every time!

So again, thanks for your knowledge and advice regarding using my TTL converter with MF-1.  Very helpful!!

Stewart

3 hours ago, eyeguy said:

I had the opportunity tonight to try the MF-1 with the camera set to Auto FP and the flash compensation set to +1 ev.  If fired every time!

Good news!  The problem is solved.

Some differences in concrete TTL board User Manual may took place, if the text had been edited before MF-1 appeared on the market. No problem. I will ask Nauticam to add this information to text.