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stuartv

How to shoot TTL? (a7r4, UWT, Z330)

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I know this has been hashed out before, but I can't remember how to do it and I can't find the old posts.

I'm shooting a Sony a7rIV, with a UWT TTL trigger, S&S fiber optic sync cords, and Inon Z330 Type 2 strobes.

I ran it just fine with everything on Manual, all last week.

But, I wanted to experiment some last week with shooting using TTL and I could not make it work for me at all.

I want to keep the camera on Manual - so I control shutter, aperture, and ISO. I want the camera/trigger to just use TTL to control the strobes.

 

Can one of y'all give me a quick run-down of the things I need to set to make this work?

 

UWT dial set to 1 (the position for Inon, I think - I realize that may only be for a Z240 and I may be screwed on not having a trigger with a Z330 setting).

Camera, WL Flash On?

Magnet Out?

Strobe knob turned to STTL?

Anything else?

 

And then, just so I am CLEAR, for all Manual:

UWT dial doesn't matter.

Camera, WL Flash Off.

Magnet In.

Strobe knob turned to M.

Correct?

 

Side note: I shot on manual everything last week. But, I just noticed that my magnets on the strobes were out. And yet the strobes were firing and illuminating my subjects correctly. I don't understand that. I would have expected that with the magnets out, the strobes would be expecting a pre-flash and so not fire correctly when the trigger sent the flash. Since they did seem to work fine, maybe I should leave the magnet Out all the time, whether I'm shooting full manual or manual with strobe TTL? Or did I just get really lucky last week and the pre-flash flash on my strobes just happened to be the right amount (more or less) all the time - and I didn't notice that the flash power was not actually changing when I adjusted the power knob?

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You need to move the power dial to the neutral position as your initial flash exposure, pointing straight up (at least on Z-240).

As far as I can tell the INON (at least my Z-240)  ignores the pre-flash but still mimics it, but as a very low power pulse.  I tried it with my Z-240.  Put it in manual and triggered with a single low power flash from the onboard flash.  with the magnet out the flash still fired but only low power and did not vary with the dial.  It's perfect for fooling you into thinking the flash is going off as you can see the strobes fire but the pulse is too weak to do much.

Tried the same thing with on board flash set to TTL rear curtain sync - so I can see the both preflash at the beginning and main flash at the end if the shutter speed is slow enough.  Then with magnet out it fired the low powered pre flash pulse and the main pulse, but the difference this time is that the main pulse changes as you adjust the power dial.

It sounds like you are getting a pre-flash out of your flash trigger.  EIther that or the Z-330 is programmed a little different and actually fully imitates the "pre-flash" .  I don't know if you set your board to fire in rear curtain sync - if you can it's useful to nut out what is going on.

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48 minutes ago, ChrisRoss said:

You need to move the power dial to the neutral position as your initial flash exposure, pointing straight up (at least on Z-240).

As far as I can tell the INON (at least my Z-240)  ignores the pre-flash but still mimics it, but as a very low power pulse.  I tried it with my Z-240.  Put it in manual and triggered with a single low power flash from the onboard flash.  with the magnet out the flash still fired but only low power and did not vary with the dial.  It's perfect for fooling you into thinking the flash is going off as you can see the strobes fire but the pulse is too weak to do much.

Tried the same thing with on board flash set to TTL rear curtain sync - so I can see the both preflash at the beginning and main flash at the end if the shutter speed is slow enough.  Then with magnet out it fired the low powered pre flash pulse and the main pulse, but the difference this time is that the main pulse changes as you adjust the power dial.

It sounds like you are getting a pre-flash out of your flash trigger.  EIther that or the Z-330 is programmed a little different and actually fully imitates the "pre-flash" .  I don't know if you set your board to fire in rear curtain sync - if you can it's useful to nut out what is going on.

 

I failed to mention, but yes, my power dial was set to the neutral position during all my testing.

I should also add at no time during any of what I have done could I detect that the strobes did 2 flashes (i.e. a pre-flash and then a real flash).

My camera flash setting is set to "Fill". I guess I should add that setting to the list of things I'm asking about for what they should be set to in order to have the camera/trigger control the strobe using TTL.

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Also, I just consulted the UWT manual for the trigger. I found that there is a Z330 setting, which is position 6. I changed mine from 1 to 6.

Per the manual, I also pushed the magnets on the strobes in and locked them down, set the mode knob to STTL, and confirmed I had the power knob set correctly. WL Flash On, Silent Shooting Off, e-Front Curtain Shutter Off. Distance to subject, 3 - 4 feet (>1m).

 

It still does not seem to use TTL at all. The strobes fire, but I can't detect any pre-flash. Only 1 flash at all.

 

When I set the camera to f/8 and ISO 400, the result it totally overexposed. When I set it to f/16 and ISO 100, the result is a little underexposed. All with SS of 1/200.

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59 minutes ago, stuartv said:

 

I should also add at no time during any of what I have done could I detect that the strobes did 2 flashes (i.e. a pre-flash and then a real flash).

When I set the camera to f/8 and ISO 400, the result it totally overexposed. When I set it to f/16 and ISO 100, the result is a little underexposed. All with SS of 1/200.

You won't be able to detect pre-flash by eye as the preflash and main flash are too close together, you can only detect this electronically when you are in normal front curtain sync flash settings.  You can only visually detect it if you are in rear-curtain sync  and the shutter speed is something like 1/2 sec or longer so you can see the two flashes - you can see both flashes in this mode as the pre flash is at the start of the 1/2 sec exposure and the main flash at the end.  This is just a tool to try to work out what is going on, not a setting you would use during shooting. 

You can go down the burrow to work it out or take the path of least resistance and just  put the magnets in on manual.

As far as getting TTL to actually work, you should be able to do a test on land like take a shot of something up close like 1 ft away then another shot 10-15 ft away and get approximately the same exposure on each without moving the settings at all - taking care that you can get the right exposure on the distant target in manual, it always possible you might be out of range.  If it doesn't work, cycle through the flash modes you have available.  

If I understand your last sentence correctly - it appears you are getting a constant manual flash perhaps?

There could be a number of things going on which may take some experimenting to figure out.  Do you have access to a flash meter to see how the strength of the flash varies as you change settings?

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11 minutes ago, ChrisRoss said:

You can go down the burrow to work it out or take the path of least resistance and just  put the magnets in on manual.

As far as getting TTL to actually work, you should be able to do a test on land like take a shot of something up close like 1 ft away then another shot 10-15 ft away and get approximately the same exposure on each without moving the settings at all - taking care that you can get the right exposure on the distant target in manual, it always possible you might be out of range.  If it doesn't work, cycle through the flash modes you have available.  

If I understand your last sentence correctly - it appears you are getting a constant manual flash perhaps?

There could be a number of things going on which may take some experimenting to figure out.  Do you have access to a flash meter to see how the strength of the flash varies as you change settings?

 

I can run them on Manual, as I have been. I just WANT to experiment with TTL.

 

I could do what you said - moving back and forth. But, what I'm doing is changing between f/8 and ISO 400 and f/16 and ISO 100. Shouldn't that have the same effect? If TTL is working, then both combos should result in the same exposure. That is, of course, presuming that my subject is lit so that both combos CAN produce a good exposure by just varying the flash.

 

Yes, that was my point. It does SEEM like I am getting a constant flash. The manual for the UWT specifically says to put the magnets in for TTL shooting. That seems wrong, to me.

 

I do not have access to a flash meter.

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4 hours ago, stuartv said:

WL Flash On

There's your problem. WL = manual mode, it only emits one flash, no pre-flash. With the UWT converter, this allows you to manually set flash power from the camera using flash compensation - you put the strobes in TTL mode, camera in WL flash mode, and then flash -3/+3 range of compensation in-camera results in a range of flash power settings replicated by the strobes.

If you want to shoot TTL, you have to use either flash auto, slow or rear curtain sync modes; this will produce a metering pre-flash followed by the actual flash timed to coincide with exposure.

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@ChrisRoss, I changed to WL Flash Off, as @Barmaglot suggested.

Camera flash is set to "Fill". SS is 1/200. It sure seems like I can detect a double flash now.

 

But, TTL still doesn't seem to work right. However, it's weird. I have both my strobes set the same (Mode on STTL, Power straight up). Magnets in or out does not seem to make any difference on either strobe.

I'm shooting at f/8 and ISO 400, then changing to f/16 and ISO 100. Shooting the light switch on the wall 3 or 4 feet in front of my camera, and comparing the exposure between the 2 combos of settings.

When I do it with one strobe, one setting gives a good exposure and the other is blown out. When I do the shot with the other strobe, one setting gives a good exposure and the other is very dark.

 

The fact that through all this it seems like my magnets being in or out doesn't make any difference. That has me wondering if I need to backup up a step and make sure the magnet switches actually work like they're supposed to. The strobes are brand new, so I have been assuming they do, but maybe not...

 

To test the magnets, correct me if I'm wrong:

 

Camera flash: WL Flash On.

Camera flash mode: Fill

Camera mode: M

Strobe mode: M

Take a picture with the magnet out: Picture should be dark, as strobe should not fire (expecting a pre-flash that never happens)

Take a picture with the magnet in: Picture should be bright, as strobe should fire on the one and only trigger flash

 

Correct?

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Sounds about right, can't really comment on the WL mode.  The thing to remember with INON is they have an advanced cancel circuit which according to their blurb boosts the pre flash so the camera thinks it only needs a low duration pulse to get the exposure correct.  The flash knows how it has changed the pre-flash pulse and adjusts the actual pulse it transmits to give the right exposure.   The object is to preserve camera battery life.  Magnet out disables the advanced cancel circuit. 

So what should happen is the only change between magnet in and magnet out is the brightness of the pre-flash.  Thinking about it further if you are using a flash trigger then probably you want magnet out - if only to take the advanced cancel circuit calculations out of the equation.  As you said you need the magnet in to shoot manual strobe(manual on camera/flash trigger and manual on strobe).  So this means if you can shoot manual your magnet is working. 

The other thing to consider is that there are three pieces of equipment in play here - the camera, the flash trigger and your strobe.  In TTL your camera and trigger communicate to sort out the signals.  The camera/trigger and the strobe have no idea what the other is doing or is about to do and only respond by putting out or receiving signals via fibre optic.  So the camera could be changing the exposure or the strobe could be doing it - another layer of complexity with TTL.

The point of all that is the camera recalculates the flash exposure each time and it could change if your framing changes or if there are reflective things in frame - if the angle the light hits it changes.  If you are going to do these tests I would suggest mounting your camera on a tripod and ensuring you don't move your strobes between test exposures.  I'd also suggest setting up on a fluffy toy or something sitting on carpet which is not reflective.

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I was really hoping @Pavel Kolpakov would chime in here and tell me the exact settings on the a7rIV and the Z330 in order for TTL to work with the UWT trigger.

The info posted in this thread directly contradicts what the UWT manual says and none of it seems to work for me. But, also, I am doing all my testing on land. Maybe that is a problem also, but I really would like to get into the water knowing what my settings are SUPPOSED to be in order for TTL to work - not getting in to test all these different combinations of settings.

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Posted (edited)

Hello Stuart,

I can help you to make proper setup, including all settings. Let's do it step by step.

What is your TTL-Converter model and fiber optical cable model?

Edited by Pavel Kolpakov

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7 hours ago, Pavel Kolpakov said:

Hello Stuart,

I can help you to make proper setup, including all settings. Let's do it step by step.

What is your TTL-Converter model and fiber optical cable model?

 

UWT 11075 TTL converter for Sony

Sea & Sea fiber optic cables, L-type, 18 inch

Camera is a Sony a7rIV

Strobes are Inon Z330 Type 2

 

Thank you!

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Posted (edited)
23 hours ago, stuartv said:

UWT 11075 TTL converter for Sony

Sea & Sea fiber optic cables, L-type, 18 inch

Please specify the TTL-Converter model. The model full number is written in its User Manual and on the carton box too. Since 2020 there were issued 3 different products based on 11075 model:  #1075, #11075-II, #11075-HSS. 

Also, please specify the optical cable model.  Is it Sea&Sea cable of former years, or new 613-core?  This is very important for LED system usage. Sea&Sea currently produces 3 new cables of 613 type. The "L" length cable is product No.50133 - https://www.seaandsea.jp/products/strobe/accessory/020.html  Do you use exactly this cable model? If yes, Ok.  So, you probably also use screw caps of third party manufacturer, to connect such cable to Z330 and to Nauticam housing?

Can you please show a photo of your setup, on the table. Let's check the hardwire first.

Edited by Pavel Kolpakov

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4 hours ago, Pavel Kolpakov said:

Please specify the TTL-Converter model. The model full number is written in its User Manual and on the carton box too. Since 2020 there were issued 3 different products based on 11075 model:  #1075, #11075-II, #11075-HSS. 

Also, please specify the optical cable model.  Is it Sea&Sea cable of former years, or new 613-core?  This is very important for LED system usage. Sea&Sea currently produces 3 new cables of 613 type. The "L" length cable is product No.50133 - https://www.seaandsea.jp/products/strobe/accessory/020.html  Do you use exactly this cable model? If yes, Ok.  So, you probably also use screw caps of third party manufacturer, to connect such cable to Z330 and to Nauticam housing?

Can you please show a photo of your setup, on the table. Let's check the hardwire first.

The trigger box says "# 11075-HSS"

I actually have 2 sets of fiber optic cables that I can use.

One set is Sea&Sea Fiber-Optic Cable II M/2 (product # 50128). https://www.seaandsea.jp/products/strobe/accessory/020.html#50128

The other is a brand new set of Backscatter Universal Fiber Optic Cable with attachments for Nauticam and Inon (product bs-foc). https://www.backscatter.com/Backscatter-Universal-Fiber-Optic-Cable

The Backscatter cables and connectors are what is currently on the camera and shown in the attached picture. This setup worked just fine all last week while shooting in the North Carolina Wreck Shark Shootout, so I don't think there is any problem with the strobes or cables. You can see in the other photo that I have been getting the light I wanted, from both strobes. But that was all in strictly Manual mode.

The question is what are all the necessary and correct settings to use manual shutter, aperture, and ISO, while having TTL control the strobes firing.

2022-06-12 10.38.55.jpg

DSC02457-Edit-2-Edit-Edit.jpg

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Just checking in. Still hoping for some help here. :)

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On 6/12/2022 at 5:39 AM, Pavel Kolpakov said:

Please specify the TTL-Converter model. The model full number is written in its User Manual and on the carton box too. Since 2020 there were issued 3 different products based on 11075 model:  #1075, #11075-II, #11075-HSS. 

Also, please specify the optical cable model.  Is it Sea&Sea cable of former years, or new 613-core?  This is very important for LED system usage. Sea&Sea currently produces 3 new cables of 613 type. The "L" length cable is product No.50133 - https://www.seaandsea.jp/products/strobe/accessory/020.html  Do you use exactly this cable model? If yes, Ok.  So, you probably also use screw caps of third party manufacturer, to connect such cable to Z330 and to Nauticam housing?

Can you please show a photo of your setup, on the table. Let's check the hardwire first.

 

I'm just checking in here. Still hoping for some help with this.

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Posted (edited)
On 6/12/2022 at 5:48 PM, stuartv said:

The question is what are all the necessary and correct settings to use manual shutter, aperture, and ISO, while having TTL control the strobes firing.

I made a short video about #11075-HSS UWTechnics TTL Converter initial test and correct settings:

(i forgot to say: some Sony cameras allow to set 2-nd curtain electronic (or fully electronic shutter), - don't use it with TTL-converter). Only 1-st curtain can be set electronic if you need).

 

Edited by Pavel Kolpakov
  • Like 1

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1 hour ago, Pavel Kolpakov said:

I made a short video about #11075-HSS UWTechnics TTL Converter initial test and correct settings:

(i forgot to say: some Sony cameras allow to set 2-nd curtain electronic (or fully electronic shutter), - don't use it with TTL-converter). Only 1-st curtain can be set electronic if you need).

 

Awesome! Thank you! I will watch and try it out and let you know how I fare. 

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