TTL systems in underwater photo

[Captain Fathom 8]

This intended to Stuartv:

The magnet switch has no function when the Z240 is set to sTTL. The strobe defaults to the expectation of a preflash regardless of the switch position. In strobe set to eAuto or strobe set to Manual the magnet switch does cancel the expectation of a preflash when the magnet is out and sets for preflash when in.

My A6400 always preflashes (which is kind of stupid Mr. Sony) even when the camera is set to Manual. Therefore when the trigger is set to 0 position the trigger provides a single synchronized pulse to fire the strobes and in this configuration the strobe magnet switch should be out. When you set the trigger to the "profile" selection for sTTL then the strobe magnet switch should be in and this because the trigger will provide a preflash so the strobe needs to be set to expect the preflash, which of course is how sTTL works.

Now continuing, note in the TTL converter instruction sheet the information on selecting camera command WL (wireless) when in camera Manual mode. The WL provides a command to the TTL converter to provide sync without a preflash. Therefore your strobe should be in Manual and the magnet switch should be out. If however, you wish to use strobe sTTL with camera selected to Manual then turn off the camera command WL and select the strobe magnet switch to in and set the strobes to sTTL. Think about this, this is really powerful because it lets you bounce between 1) sTTL with preflash and camera set in Manual with strobes set in sTTL and 2) camera set to Manual and strobes set in Manual and no preflash. This by turning on and off the WL command (I think that is how it works).

If the TTL converter or camera ( not sure which is getting confused) gets confused then cycle the camera to OFF and then back to ON. This should clear the fault. 

If you want to do ambient light without flash and want to access the full range of shutter speeds, select (preset command to a configurable button) Silent Shutter in your menu. The TTL converter will no longer function. I have found that when I turn off Silent Shutter, the TTL converter may or may not come back on line. If you wish to bring the converter back on, reboot the camera. Now the TTL converter should return to normal operation.

I hope I am not misleading you. I dive my new camera on the dining room table before going on a trip. Trips are too stressful to work out a new system, at least for my poor brain.

 

James

Edited February 22, 2020 by Captain Fathom

[Pavel Kolpakov 78]

4 hours ago, stuartv said:

.....

Hi Stuart,

First of all, I advice to change the batteries CR2032 in TTL-Converter to new, to avoid potential problems from this side. After it, check and move HotShoe cable connections.

On land in comfortable conditions, test the TTL-Converter functionality according the User Manual, carefully step by step. Everything is described very easy there. Pay attention to camera settings and Z240 settings. If you need, here is online version User Manual for #11075 TTL-Converter: https://ru.calameo.com/read/00556083657cf35cf88c8

If finally you recognized that concrete unit is really broken /defected, please contact manufacturer by e-mail (uwtechnics@gmail.com) or your dealer, for replacement.

Edited February 22, 2020 by Pavel Kolpakov

[stuartv 34]

After several days of emailing back and forth with my dealer (Reef Photo), and trying changing the trigger setting to 0, putting in new batteries, changing it back to 1 (for Inon Z240), as far as I can tell, this trigger does not work right. In full Manual mode (camera and strobes), I finally got it to stop doing the pre-flash, by setting the camera setting for Wireless Flash to WLon. But, it still only fired the strobes some of the time. I verified the problem was the trigger by pulling the optic sync cable out of the housing socket and snapping some pictures - seeing that the optical trigger did not fire. When I tried this and the times that the trigger DID fire, I could clearly and easily see a red flash from the trigger LED. So, when I was snapping a photo and that trigger LED did not flash, it was quite obvious.

 

I'm sending the housing back to Reef and will probably have them just go ahead and replace the trigger with the ($200 cheaper) Nauticam optical trigger. I have always only shot in full manual anyway. I thought TTL might be nice on occasion for some specific scenarios. But, 100% reliability is far more important to me than very occasional TTL support. I just dived 6 straight days in Utila and had quite a few good photo opportunities. Virtually every one of them was ruined by not having strobes that worked. It was SO frustrating! I wanted to throw my whole camera rig on the bottom and leave it! A week's photo vacation wasted.

[stuartv 34]

On 2/22/2020 at 4:03 AM, Pavel Kolpakov said:

Hi Stuart,

First of all, I advice to change the batteries CR2032 in TTL-Converter to new, to avoid potential problems from this side. After it, check and move HotShoe cable connections.

On land in comfortable conditions, test the TTL-Converter functionality according the User Manual, carefully step by step. Everything is described very easy there. Pay attention to camera settings and Z240 settings. If you need, here is online version User Manual for #11075 TTL-Converter: https://ru.calameo.com/read/00556083657cf35cf88c8

If finally you recognized that concrete unit is really broken /defected, please contact manufacturer by e-mail (uwtechnics@gmail.com) or your dealer, for replacement.

 

Hi Pavel,

 

Thanks for the link to the manual. That did help in that the manual finally showed me where the WLon/WLoff setting is in the camera settings menu. Reef Photo support had mentioned changing that setting, but they didn't tell me the name in the menu itself is "Wireless Flash".

 

What I did:

 

I put in 2 new CR2032 batteries.

 

I changed the trigger dial from 0 back to 1 (for Inon strobes).

 

I was shooting with the camera in M mode, with an explicit ISO setting (not AutoISO), WLon, and the strobes set for M mode.

 

Like that, it no longer did pre-flashes from the strobes. So, that part was good.

 

But, the strobes would still only fire less than half the time. And this was with multiple seconds between shots (and Eneloop Pro batteries). To verify that the problem was with the trigger itself (or the camera, I suppose), I pulled one of the optical sync cables out of the housing port and shot a few photos. When the trigger fired, I could easily see a bright red LED flash from the port on the housing where the trigger LED was. When the one strobe that was still connected did NOT fire, I could easily see that it was because the trigger LED did not flash.

 

I conclude that the problem is either the trigger itself or the camera. It's not the sync cables or strobes. And, of course, I am skeptical that it is the camera itself. During my week in Utila working on this, I did remove the trigger module from the camera's hot shoe and reinstall it several times, so I also do not believe my problems are anything to do with not having that connection made properly.

 

I have already emailed Reef Photo to make arrangements to send my housing back to them to have the trigger module replaced. At the moment, I'm on the fence about having them replace it with a Nauticam trigger. I have only ever shot in M mode (i.e. no TTL) before, so I don't NEED TTL. I paid extra for the UWT trigger because I thought TTL might come in handy in the future for some very specific cases. E.g. it might be handy for shooting macro, if I ever start to do that. But, reliability is far more important to me than having TTL. So, I'm kind of leaning towards having them replace the UWT with a Nauticam trigger. However, I am open to anyone's thoughts on the subject.

[Pavel Kolpakov 78]

15 hours ago, stuartv said:

....

Hi Stuart,

I think, it maybe a defected / broken unit. Why no. Everything can happened during the installation or transportation the product to dealer or etc. If you e-mail to manufacturer, they will send you the replacement the same day, no problem with it.

 

[stuartv 34]

@Pavel Kolpakov I have just done some testing with the trigger. Just shooting in my house (dry), with no strobes hooked up, watching the trigger LEDs. I now suspect that my trigger is not defective, but rather that it has a bug (or more) in its implementation.

 

At first, it seemed the trigger was working perfectly.

 

Then I let my camera sit until it went into Power Save Sleep mode (or whatever it is called). Once it does that, THEN I am able to reproduce cases of the trigger sometimes not firing.

 

Related note: My camera is fairly new to me. It is set to the default of 1 minute before it goes into Power Save mode. It kept doing that to me repeatedly during my dives last week. I kept telling myself to figure out how to change that once I got out of the water - but I kept forgetting to look for the setting that controlled that, so it was like that all week (i.e. 1 minute until Power Save mode kicked in). Thus, it happened to me often.

 

One specific example that seems reliable to reproduce the problem behavior: Camera is in PS mode. Camera is set for Mid speed continuous drive. I press and hold the AF-On button and then pull the shutter release and hold it. The camera takes a second or two to wake up, but then it starts taking pictures (at several frames per second). The trigger LEDs never fire at all in that example.

 

I was also able to reproduce the problem another way, but it was not reliable to happen every time. Camera is in PS mode. Camera is set for Single Shot drive mode. I press AF-On and the shutter release, hold it briefly and then let go. Then start hitting the shutter release repeatedly. Sometimes the trigger LEDs would not fire.

 

It also SEEMED like it could be related to trying to shoot while the buffer was still clearing from the last string of photos taken.

 

Thoughts?

[Pavel Kolpakov 78]

Friends asked to write some classic advantages of LED TTL-Converter vs small Xenon Flash (built-in flash, or  small optional) for synchronization with underwater strobes. They are as follows:

1) Reflections, blinks through the port hole to optics.

Xenon powerful flash produces a strong light widely inside the housing. In many cases user can see some reflections on the image, because some light from flash goes to the dome port from inside. Usually it takes place in case the objective diameter is significantly smaller than port mount diameter. User even can see objective digital scale on the picture sometimes. I also have such defected shots in my stock. Manufacturers improve housings from year to year, but the issue is still not solved completely yet.

But the LED device solves the issue. It has narrow 8-degrees beam angle and it lights directly to the optical bulkhead (fiber cable end).

 2) Batteries life

Xenon flash consumes large size batteries and rather fast. User has to change those batteries often. But impossible to change battery underwater during the dive. Also, in some dive trips can be difficult to change the batteries. This is important for those people who make a lot of shots.

The LED TTL-Converter uses smaller batteries, and the battery life is about 1 year and more. It has micro current consumption.

3) Xenon flash overheating

After continuos flashes inside the housing the pop-up flash sometimes switches off, because of overheating. There is a thermo sensor inside the xenon flash, which saves it from overheating. When we have thermo shutdown, we cannot shoot, but must wait for flash cooling.

But the LEDs does not heat, there is no temperature issue with LED devices.

4) Xenon flash significant recharge time

Xenon flash has a classic high voltage tube and capacitor which requires significant time for recharging (2-8 seconds). User can not shoot fast series, he has to wait for sync device recharging, some important shots can be lost. Continuos high speed shooting is impossible.

But LED devices allow continuous fast shooting, they don't have any recharge time, no inertia. Continuos shooting modes are available with LED. I tested continuos camera mode at 8 shots per second with Z-330 (M mode, at minimum power), it worked normally.

5) Xenon small  flash duration is not enough for getting full power from uw strobe

Powerful underwater strobes usually have significantly bigger size tube than small pop-up flash (or optional flash) which we use for synchronization. The small tube has small flash duration about 0.5 ms. But Z-330 full flash duration is 3.5 ms. Control is going according the duration. User never can get full flash power from uw strobe, using a small xenon flash for TTL synchronization.

TTL-converter (Z330-profile in firmware) has firing time exactly 3.5 ms for Z-330, so the full power is available for TTL control. LED TTL Converter is specially developed for underwater strobes control.

6) UW strobe TTL accuracy is not good enough via small xenon flash control

Small xenon tube and Z-330 xenon tubes have different discharge curve shape and length, all timings are different for the concrete values, that is why TTL accuracy sometimes is not very good under small xenon flash synchronization. In some shooting situations accuracy is acceptable, but in some cases it is not.

But TTL-Converter's  firmware includes special TTL-profile for each type underwater strobe, TTL accuracy is better.

7) Optical TTL control / Electric TTL control (external strobe connections)

Small xenon flash suggests only Optical TTL control, nothing more.

Most of TTL Converters have combined TTL electronics onboard: Optical TTL + Electric TTL. So, photographer can use fiber optic cable, or electric 5-pin sync cord (Nikonos, Ikelite, S-6), also can change them when he wants. He also can use both type cables (fiber + electric) simultaneously. These are extended capabilities for uw strobe's TTL control in case of TTL-Converter usage.

8) Underwater strobes HSS functionality is available via TTL-Converter usage

New generation HSS strobes, like "Retra Pro" for example, in common case requires a LED Converter with specially developed firmware for concrete HSS version support. UWTechnics produces such Converters (they have "HSS" index in name). But using xenon flash synchronization, that HSS function of uw strobe does not work with most of camera brands (excluding Nikon). So, for underwater strobe HSS feature, photographer has to use TTL-Converter in common case.

9) Available more fast X-Sync shutter speed for TTL

Some cameras allow to set faster X-Sync shutter speed using TTL-Converter, than without it. For example, Sony A7-A9 family allows to set 1/160s X-Sync speed in common case, but using TTL-Converter it allows 1/250s. Because TTL-Converter has specially developed firmware for such camera protocol support.

Edited March 26, 2020 by Pavel Kolpakov

[Algwyn 12]

@Pavel Kolpakov aren't some of the issues reduced when using on-board flash in "Commander" mode, like on Nikon cameras?

[Pavel Kolpakov 78]

10 minutes ago, Algwyn said:

@Pavel Kolpakov aren't some of the issues reduced when using on-board flash in "Commander" mode, like on Nikon cameras?

Yes, of course, it is possible to reduce some problems of xenon flash by applying various measures. And photographers usually do it. But in the post above i mean comparison in general. 

[TimG 62]

Thanks for this readout, Pavel. Fascinating stuff.

[stuartv 34]

Some info and a question for @Pavel Kolpakov.

 

Pavel, the instructions for my trigger (for Sony a7rIV) strongly recommend to set the camera's Power Save timeout to 10 seconds. That means that after 10 seconds of inactivity on the camera, it goes to sleep. If something comes along that I want to shoot, it takes the camera around 2 seconds to wake up before I can start shooting.

 

That really does not work for me. When I am diving with and shooting sharks, it is not unusual to go 5 or 10 minutes (or more) waiting for the "right" composition to come together. I need to be ready during that whole time. When it happens, I will not often have 2 seconds of warning to get ready.

 

If I keep my camera "awake" during the (almost) entirety of each dive (whether that is by changing the Power Save timeout or by pressing the AF button or something else on the camera, to keep it awake continually), what is that really going to do to the trigger battery life? Is there some approach I can use to this that will give me reasonable assurance that I won't have my trigger batteries die during a dive day? Changing trigger batteries while out on a boat is not something I would even attempt.

 

On to the "information". I got my first UWT trigger back in Feb. It turned out to be defective. Bad firmware, from what Pavel posted. It seemed to work fine in living room testing. But, in a week in Utila I found that it would very often go out to lunch and refuse to fire. Reef Photo sent me a new trigger, but that had to wait to receive it from UWT, so it finally arrived yesterday.

 

I had done some extended living room testing with the old trigger and was able to reproduce the behavior of not always firing. Repeating that testing with the new trigger seems to indicate that the new trigger is "fixed".

 

But, I did find what I consider to be a bug in my Sony a7r IV's firmware. If the camera goes into Power Save mode (i.e. goes to sleep), I can press and hold the shutter release and the camera will take 1 - 2 seconds to wake up and then it will start capturing images. But, in that scenario, it will not fire the flash. It will only fire the flash if I hit the shutter release after the camera has awakened completely.

 

I tested this with the UWT trigger, in my housing (by just watching the trigger's LEDs). And I tested it with the camera out of the housing and my Godox V1 speedlight mounted in the camera's hot shoe. Same behavior with both items. Camera in M, with continuous drive. Camera goes to sleep. I press and hold the shutter release, or press and hold the BBAF, then also press and hold the shutter release. The camera wakes up and starts grabbing 10 fps, with no flash firing at all. If I just let go of the shutter release and hit it again immediately, it resumes grabbing images and the flash/trigger immediately starts flashing away.

 

I posted about this issue in an a7r group on FB and another member tested it on his a9 II and said it does not have this problem. His flash starts firing along with the shutter as soon as the camera wakes up.

 

I set my Godox on M and to its lowest power setting. It was kind of cool to see it flashing away at 10fps... Sometime, I'll have to test it to see what the max power level is where it can sustain flashing at 10 Hz.

[Pavel Kolpakov 78]

43 minutes ago, stuartv said:

..... recommend to set the camera's Power Save timeout to 10 seconds. That means that after 10 seconds of inactivity on the camera, it goes to sleep. ....

Power saving time 10 sec is just a recommendation for maximum battery saving. Because TTL-Converter switches Off when camera goes to standby mode. As i know, many users set 1 minute, it is acceptable time for normal shooting. I agree, we have to write 1 minute in instruction.  If you need 2 min or 5 min active camera screen between two shots, no problem to set it.  Battery life will be some reduced, but not significantly for real dives. Sometimes you can keep your camera active the whole dive, if it is an important dive, no problem.

Edited March 27, 2020 by Pavel Kolpakov

[stuartv 34]

26 minutes ago, Pavel Kolpakov said:

Power saving time 10 sec is just a recommendation for maximum battery saving. Because TTL-Converter switches Off when camera goes to standby mode. As i know, many users set 1 minute, it is acceptable time for normal shooting. If you need more, no problem, set significantly more time. Battery life will be some reduced.

 

Thanks, Pavel. I will probably set it to 10 minutes, just to be safe.

 

Is there any way to tell when I need to replace the batteries, short of having them actually go dead?

[Pavel Kolpakov 78]

1 hour ago, stuartv said:

Is there any way to tell when I need to replace the batteries, short of having them actually go dead?

Difficult to say for sure, because batteries on the market have different quality. Some of them keep high pulse power (for LEDs) good enough till the end of battery life, some batteries are rather bad in that. In common case, better change them significantly before they are go dead.

I have a few housings in my own usage. Mainly, i change batteries 1 time per year in them. But i shoot not very often. Anyway, if i go to an important dive trip, i change all batteries in my equipment before the trip, just for insurance. 

Edited March 27, 2020 by Pavel Kolpakov

[Kraken de Mabini 176]

Some suggestions to "When to replace a Battery ?":

a) Start the dive trip with new or fully charged batteries, as Pavel suggests.  Use the best batteries available, they pay for themselves.

b) Use a digital voltmeter to measure the battery's voltage: If it is significantly below the battery's nominal voltage, replace the battery. One learns quite fast when to replace. Digital VOM's are quite small, light weight, inexpensive and readily available on eBay. Carry one on trips away from home, they can be given as a nice gift at the end of the trip.  

c) It is a good idea to carry spare batteries for the lamps, strobes, camera, vacuum leak detector... Don't forget the chargers. 

If you do not need them, a fellow diver will - great way to make new friends!

 

[bvanant 190]

Given a typical NiMH discharge curve a digital VM is really not a good way to test AA batteries. Better to use a pulse load tester like the one from ZTS. With a voltmeter you might be at only 10% capacity and not know it.

 

[Captain Fathom 8]

My UT trigger uses CR2230 batteries, not AA/AAA. This is consistent with the moisture/vacuum alert system in the Nauticam housing. They are inexpensive enough to just replace if there is any doubt. 

 

 

[Pavel Kolpakov 78]

On 5/13/2019 at 11:22 PM, davec13o2 said:

Hello Pavel,

Referring to the TTL converter for Sony a7Rii to be released, fitting it to a Meikon case, can you recommend a retrofit to the single hole in the top of the case for fiberoptic cables to two strobes? Or would the case have to be modified for two optical bulkheads? Below are diagrams of the Meikon case hole that fits their standard sync bulkhead.

Here are UWTechnics optional bulkheads specially developed for Seafrogs (Meikon) housings. These products (#91303-Optical, #91385-Nikonos, #91386-Ikelite style) have such a special rear part. So, uw strobes can be connected both optically and electrically to TTL system now.

Edited March 31, 2020 by Pavel Kolpakov

[Lewis88 13]

@Pavel Kolpakov Do you know if the UW Technics TTL converter for Sony A6xxxx cameras in a Seafrogs housing supports the YS-110a strobes? I only see YS-D1 and above listed. 

 

[Pavel Kolpakov 78]

3 hours ago, Lewis88 said:

@Pavel Kolpakov Do you know if the UW Technics TTL converter for Sony A6xxxx cameras in a Seafrogs housing supports the YS-110a strobes? I only see YS-D1 and above listed. 

Sorry, there is no YS-110a profile in that firmware. 

Firmware includes the following TTL-profiles:

Inon Z240,

Inon Z330,

Retra Pro,

Sea&Sea YS-D1,

Sea&Sea YS-D2 (China version),

Sea&Sea YS-250,

Ikelite DS-161, DS-160

Subtronic Pro-160

Subtronic Pro-270.

 

 

[Lewis88 13]

Thanks @Pavel Kolpakov 

 

I will have to go with the TRT electronics version it seems, even though I prefer the design and leak detector replacement setup of the UWT version.

Will any of the existing profiles, such as YS-D1, work for the 110a?

[Pavel Kolpakov 78]

48 minutes ago, Lewis88 said:

Thanks @Pavel Kolpakov 

Will any of the existing profiles, such as YS-D1, work for the 110a?

YS-110a will work, but TTL curve is significantly different. As for me, the flash control will not be good enough. But that's up to you.

[Lewis88 13]

34 minutes ago, Pavel Kolpakov said:

YS-110a will work, but TTL curve is significantly different. As for me, the flash control will not be good enough. But that's up to you.

This is what I figured. I will go with the TRT electronics version.

[Pavel Kolpakov 78]

11 hours ago, Lewis88 said:

......

Result will be the same with all manufacturers TTL boards, if YS-110a profile does not exist in firmware.

Edited July 31, 2020 by Pavel Kolpakov

[Lewis88 13]

6 hours ago, Pavel Kolpakov said:

Result will be the same with all manufacturers TTL boards, if YS-110a profile does not exist in firmware.

TRT has the YS-110a as an available option in their firmware.