I'm trying to figure out if I'm doing something wrong. In the menu of my Olympus EM-10 Mark IV it has the maximum sync speed for flash set as 1/250 but my YS-D3 Duos won't fire at anything faster than 1/160.

First thing to check is if the trigger or mini flash is firing at 1/250.  Also confirm you are in manual flash on the camera.  When you say they won't fire - do you mean they won't fire at all or that they no longer sync?

The flash doesn't fire at all.

 

I think I may have found out why. I was reading the manual for the camera again and I found a note saying that when you have RC turned in (Olympus' special TTL mode) it can't go beyond 1/160. I am going to try turning it off and seeing if I can get it to work that way.

It seems like I have to go into the menu and disable RC mode to use the strobe in manual mode. It still will only let me go to 1/200 (camera won't go even go beyond that). Oh well. The manual for the strobe and the camera don't exactly paint a full picture.

Possibly the 1/250 can only be used with the built-in pop-up flash of that camera. This would make the statement „formally correct“ with 1/250 sync speed, but it is a bit misleading indeed.

The issue with trouble shooting flash operation is that the camera and external strobe have no idea about what each other is doing.  The UW strobe merely responds by triggering in repsonse to a light pulse.  The issue is that each side needs to be set to the right setting to get results.  The Olympus RC control gets around that as the camera communicates with the strobe via light pulses.

 

First of all the Olympus RC protocol can't be used to trigger strobes that are not set up for it.  Both the camera and strobe need to be in RC mode.   You could use that if you were trying to use TTL with your setup.

 

It sounds like you might be trying to use TTL.  If you are prepared to use manual control the X-sync speed is reported to be 1/250 but only with the built in flash it seems. 

 

What are you using to trigger the flash?  It is reported that using the Nauticam manual trigger bypasses the shutter speed limits.  TTL triggers can do this.

 

The built in flash should work in both manual and TTL (not RC) up to the published 1/250 limit.  It is 1/200 limit for external flash units which may include a TTL trigger.   You should be able to check all of this on the camera alone to establish your max sync speed. 

 

Set the camera to manual exposure , the flash to auto and see what SS you can reach in that.

Then repeat with camera in manual and flash set to manual to see what SS you can get to with the built in flash.

 

So here's all the data. At this point I'm probably just doing this to help out whoever ends up with this or a similar question in the future. 

 

Camera: Olympus EM-10 Mark IV

Housing: AOI with built in hot shoe-mounted optical TTL trigger

Strobes: Sea and Sea YS-D3 Duo

 

The Strobes have the following modes: TTL, RC (specifically for Olympus cameras), and Manual (able to be configured to work with cameras that pre-fire the flash all the time even in manual flash mode)

 

Camera has the following flash modes:

RC Off: Fill, Off, Slow(rear curtain sync)

RC On: There are two modes called Normal and Super FP Flash (this is Olympus' name for High Speed Sync)

RC On Normal Flash: TTL Auto, Auto, Manal, Off

RC On Super FP Flash: FP TTL Auto, FP Manual, Off

 

With RC Off, camera will not allow shutter speed to exceed 1/200. Flash works in Manual. Will fire in TTL but does not provide TTL functionality. Turning mode on flash to RC, flash does not fire.

 

With RC Normal Flash On: Shutter speed capped at 1/160. TTL Functions seem to work when selected and strobe placed in RC mode.

with RC Super FP Flash On: Shutter speed able to be selected all the way up to 1/4000. Flash does not fire at speeds above 1/160. FP TTL Auto works. Flash does not fire in FP Manual. Placing flash into manual mode results in flash firing out of sync with camera even at 1/160.

 

So, if you want to shoot with TTL, you have to go into the menu and enable RC mode on the camera and then turn the flash to RC. To shoot with manual flash and get a shutter speed of 1/200, you have to disable RC mode. Unless there is something I'm missing.

 

Sidenote, when the camera is out of the housing, the little popup flash does high speed sync just fine. I can crank the shutter speed up as high as I want. It's only when I have the TTL converter connected to the hot shoe that it locks down the shutter speeds.

I sent all of the above to Backscatter (where I bought the housing) and they replied today. They stated that the RC compatible hot shoe is only capable of 1/200 in manual and 1/160 in RC mode. If you purchase the Manual Only hot shoe it will go to 1/250 and of course you lose TTL(RC mode). I followed that up with a question about how they advertise that you can use high speed sync with their Backscatter Mini Flash and this camera and housing so I asked how that is possible. I realize that isn't the exact same setup I have, but I'm still curious. 

 

Also, something I find odd, even with the current RC mode hot shoe, I can see the LEDs flash when the camera is put in RC Super FP Flash (High Speed Sync) and the shutter speed is placed above 1/160. Also, when this happens, the Strobes make the same beep they do when they fire and are ready to fire again, they just don't actually produce a flash. Also, I can see the LED's on the housing flash red just briefly even above 1/160.

Interesting - it seems that the AOI trigger does properly support the RC mode based on what you have said.  It would be so much easier if you could use the pop-up flash for triggering as it could do all 3 modes reasonably seamlessly at the cost of a little battery life - in manual setting the flash to 1/64 power triggers things reliably in my experience and uses very little battery power.

1 hour ago, cashmorephoto said:

I followed that up with a question about how they advertise that you can use high speed sync with their Backscatter Mini Flash and this camera and housing so I asked how that is possible. I realize that isn't the exact same setup I have, but I'm still curious. 

High Speed Sync is not 1/250s; it's a completely different mode of operation. In regular flash x-sync, the camera shutter opens, the flash fires a pulse, then the camera shutter closes. However, the shutter blades (or, in older cameras, fabric curtains, which is where the terms 'front curtain' and 'rear curtain' come from) can move only so fast, so above a certain shutter speed, the rear curtain starts closing before the front curtain is fully open, creating a strip of exposure that races across the frame - firing a monopulse flash in this mode will produce a partially exposed image (usually dark top or bottom), hence the camera-dependant shutter speed limitation of flash shooting. High Speed Sync overcomes it by rapidly flickering the strobe (I've seen a figure of 40kHz quoted) instead of firing a single continuous pulse, which allows it to sync at pretty much arbitrary speeds, but significantly reduces overall power.

Yes, I am familiar with what HSS is. Underwater photography is new to me, but photography in general isn't. 

 

Backscatter specifically advertises that you can use their mini flash 2 with has all the way up to 1/4000. While I realize I don't have that strobe, I'm interested to know how they manage that given the limitations they stated to me about the two different hot shoe connections.

4 hours ago, Chris Ross said:

Interesting - it seems that the AOI trigger does properly support the RC mode based on what you have said.  It would be so much easier if you could use the pop-up flash for triggering...

Yeah, but this housing gets the job done and didn't cost much so I'm fine with it in the end. Sure, it has its limitations but if I were going to spend Nauticam housing money I would buy one for my Sony a7iv.  I probably will do that one day. 

2 hours ago, cashmorephoto said:

Yes, I am familiar with what HSS is. Underwater photography is new to me, but photography in general isn't. 

 

Backscatter specifically advertises that you can use their mini flash 2 with has all the way up to 1/4000. While I realize I don't have that strobe, I'm interested to know how they manage that given the limitations they stated to me about the two different hot shoe connections.

It's possible that the AOI trigger does not properly support the RC mode required to trigger HSS flash in this scenario - check with Backscatter to be certain. You could probably replace it with a Turtle trigger, which does support HSS, but that's a fairly expensive way to access a very niche feature.

Edited December 6, 2024Dec 6 by Barmaglot

I use an epl-5 with the little add-on strobe (in the Olympus housing), this connects through the accessory port and is likely very comparable to the EM-10 pop-up. This syncs at 1/250, but any strobe on the „real“ hot-shoe will only sync at 1/160. The manual also states that rc mode with the little guy only works down to 1/160.

I once tried an old strobe from the analog days (risky, as some of those can damage the electronics) and that worked at ANY speed. Thus, the hot-shoe gets a simple electric signal (contact closed) whenever the camera takes a pic. This is of course in manual mode (for speed and f-stop). I found that I could even go 1/320 with this and did not see any shadowing by the shutter curtains. That may not be 100% reliable, though, and perhaps in 1 out of 20 shots there will be some shadowing? 

Long story short: It is possible that the AOI „manual only“ trigger might even work at shorter than 1/250 shutter speeds. The simpler the device is, the shorter one could go I suppose. However, I think that TTL is worth more than that extra short sync speed, so this is not intended as a recommendation.
 But perhaps someone here owns the manual only trigger from AOI and could share the experience?

6 hours ago, Klaus said:

I use an epl-5 with the little add-on strobe (in the Olympus housing), this connects through the accessory port and is likely very comparable to the EM-10 pop-up. This syncs at 1/250, but any strobe on the „real“ hot-shoe will only sync at 1/160. The manual also states that rc mode with the little guy only works down to 1/160.

I once tried an old strobe from the analog days (risky, as some of those can damage the electronics) and that worked at ANY speed. Thus, the hot-shoe gets a simple electric signal (contact closed) whenever the camera takes a pic. This is of course in manual mode (for speed and f-stop). I found that I could even go 1/320 with this and did not see any shadowing by the shutter curtains. That may not be 100% reliable, though, and perhaps in 1 out of 20 shots there will be some shadowing? 

Long story short: It is possible that the AOI „manual only“ trigger might even work at shorter than 1/250 shutter speeds. The simpler the device is, the shorter one could go I suppose. However, I think that TTL is worth more than that extra short sync speed, so this is not intended as a recommendation.
 But perhaps someone here owns the manual only trigger from AOI and could share the experience?

It is established that the Nauticam manual flash trigger will sync at higher shutter speeds than the published sync speed.  The key is that the strobe or trigger is triggered by the x-sync contacts which are basically an electro-mechanical switch incorporated into the shutter.  There are no electronics that tell the camera that a flash is attached so the camera doesn't lock out the higher shutter speeds, it just flashes when the X-sync contacts close momentarily when the shutter is released.

 

Whether the AOI trigger also allows higher shutter speeds depends upon the triggering circuit used - if the camera recognises it as a flash it will limit the camera to 1/250.

 

It seems the EM-10 MkIV is a special case among Olympus cameras as it has a built in pop up flash and only that will sync at 1/250.  Even hot shoe Olympus flash units that happily sync at 1/250 on other models like the EM-5 and EM-1 series will be limited to 1/200 on this model.  It's only when you get to the higher end models that 1/250 sync is universal.

15 hours ago, Barmaglot said:

It's possible that the AOI trigger does not properly support the RC mode required to trigger HSS flash in this scenario - check with Backscatter to be certain. You could probably replace it with a Turtle trigger, which does support HSS, but that's a fairly expensive way to access a very niche feature.

First, I hope I didn't seem like I was being snarky in my response yesterday. Wasn't my intention.

 

The AOI housing has no room for any other trigger. As long as this is the housing I'm using, I'm stuck with the AOI trigger. It's literally built right into the housing. I did get a response from Backscatter about how they manager HSS with their Mini Flash. Apparently the AOI trigger does support HSS (Super FP in the camera menu), which is why I can see the LEDs on the trigger firing. The YS-D3 does not support this and therefore does not receive a strong enough pulse from the trigger to fire. 

 

1 hour ago, Chris Ross said:

It seems the EM-10 MkIV is a special case among Olympus cameras as it has a built in pop up flash and only that will sync at 1/250.  Even hot shoe Olympus flash units that happily sync at 1/250 on other models like the EM-5 and EM-1 series will be limited to 1/200 on this model.  It's only when you get to the higher end models that 1/250 sync is universal.

 

The built in flash seems to immediately switch into HSS at some point so I don't know when that actually happens. When using the pop-up flash to can turn the shutter speed to whatever you want and the flash just keeps firing. I don't have the patience to figure out when it switches from full power flashes to HSS pulses.

 

At this point I just wish there was a quick way to turn RC mode on an off. Like a way to map it to a button or something.

Edited December 7, 2024Dec 7 by cashmorephoto