Old Flashes and Wireless Trigger compatibility

**W.j.christy** · 01-13-2017, 02:03 PM

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Simply put, I was thinking of using older thyristor flashes (available cheaply in many places) with a simple radio trigger to illuminate the my back round when I take portraits. Typically I use a white back ground and the goal would be to illuminate it enough to blow out and of the details of it (wrinkles, seams etc...)

So my thought is to get two older thyrister flashes with a very cheap transmitter receiver combo in conjunction with my ACON RF930's on 2 AF540FGZ's which provide the TTL lighting for the subject. I would place the cheap-o-mitter on top of the 930 transmitter to get everything to fire at the same time.

Question is, will it work, specifically will it work with P-TTL preflash.... I worry that the pre-flash will set off the older flashes then I will have lost my back ground illumination. Any thoughts on this?

Also given my quest, I was curious if anyone knew of some older flashes that have some amount of power adjustment built in, and have decent power to them.

Any thoughts or comments are welcome.

Last edited by W.j.christy; 01-13-2017 at 02:09 PM. Reason: text errors

**UncleVanya** · 01-13-2017, 02:32 PM

I am a novice at this but just started playing in this space. My reading of the cactus v6 trigger docs indicates that you can fire them optically ignoring preflash (they have their own sensor if the flash you pick does not). I would imagine the auto-thyristor part of the equation isn't going to buy you anything - I'm thinking you will want to fire the cheap flash solution on manual so you can avoid having the P-TTL flashes overwhelm the sensor but your placement may make that moot. The P-TTL measured flash may be inaccurate due to the contribution of the cheapie flashes but you can probably dial those down or up as needed via flash exposure compensation.

The cactus v6 trigger can control some TTL flashes some of which are not too expensive (for example the SB-24 nikon). The combination of a TTL flash with the cactus gives you pseudo manual control by tricking the TTL flash into thinking it needs to quench exposure at the right moment you can create the same effect as manual supposedly. At the moment I'm only using my Cactus with a dedicated RF60 and a fully manual only AF500FTZ (the AF500FTZ is not compatible with the cactus in TTL mode so I have to set manually on the flash and that flash only goes down to 1/32nd power).

The Yongnuo RF602N triggers are cheap and work great on top of the cactus (I have tried this) and will trigger any manual or thyristor flash with a reasonable trigger voltage. The newer RF602 II units I think have better trigger voltage protection.

Try searching for cactus flash compatibility to find out more about the TTL pseudo manual control options. It's pretty nice since you can have 4 groups and control them in many different ways right from the camera.

---------- Post added 01-13-17 at 04:34 PM ----------

Also many flashes have various optical slave options to ignore preflash. I'm just not sure how preflash plays on the RF side in terms of triggering.

---------- Post added 01-13-17 at 04:44 PM ----------

I did some more reading. I think that if you put a V6 where it will see the output of the P-TTL lights and set the delay on that one and have it trigger optically not electrically then it can trigger the rear cheap flashes for you ignoring the pre-flash.

Does that make sense?

There are others here with much more experience and knowledge but this might get the conversation going.

**W.j.christy** · 01-13-2017, 02:59 PM

Originally posted by UncleVanya

I'm thinking you will want to fire the cheap flash solution on manual so you can avoid having the P-TTL flashes overwhelm the sensor but your placement may make that moot. The P-TTL measured flash may be inaccurate due to the contribution of the cheapie flashes but you can probably dial those down or up as needed via flash exposure compensation.

Yep this was the goal. The cheapo thyristors would be fully manual with some way on the flash itself to dial down the power.

The idea would be to have a 4 light setup. the two AF540FGZ's up front illumination the subject with P-TTL via the ACON trigger/reciever combo, and place the thryristors behind the subject and adjust their output to properly illuminate the background, or overexpose it in the case of the white background. Something like the diagram below

----------------------------------Back Ground---------------------------------------

Thyristor ------------------------------------------------------------------ Thyristor

-----------------------------------Subject

AF540------------------------------------------------------------------------ AF540

------------------------------------- Camera

My hope is that with the Thyristors behind the subject and away from the background a significant distance the light from the thyristors should not interfere with the P-TTL function of the AF540FGZ's.....

I have seen similar set ups in photo studios used for this very purpose, i just haven't played with it yet. I am also trying to keep the cost down to under about 50 bucks, which is the reason for the desire to use old thyristors (like the vivitar 2800) and the cheap 15.00 transmitter/receiver combos from ebay such as this one Neewer 16CH Wireless Remote FM Radio flash Speedlite Trigger w/2.5mm PC Receiver | eBay.

what is considered a reasonable trigger voltage? the neewer says its good for 12v. What flashes work with that number? Any ideas?

C_Jones · 01-13-2017, 03:19 PM

I have an auto-thyristor that I have not tried with my three AF-360FGZ's. It is Vivitar. I bought it somewhere around 1990 or so to use with my Pentax K-1000 (film). Most likely it has the optical slave option, so I would resort to that if I used it. You may want to test your flashes with the optical option of an auto-thyristor to see if there is some success. Keeping your flashes and camera in Manual mode would most likely allow you to control the output more than utilizing the TTL mode.

It looks like you are receiving good advice on your situation. Good luck.

Last edited by C_Jones; 01-13-2017 at 03:29 PM.

mcgregni · 01-13-2017, 03:41 PM

The flash output of the manual radio triggered flashes will not interfere with the pre-flashes and metering of the Pentax units, because the pre-flashes and metering occur before the main trigger event ..... The Pentax P-TTL system will not 'see' this light and is unaware of it's existence.

So the Pentax system will deliver it's pre-determined flash exposure regardless ....however, at the point of exposure the additional light will record onto the sensor as additional flash exposure, so you need to take account of that and keep good manual control over the outputs. It sounds like you may be considering the two types of flash light in your scene independently, so unless there is light spill from one part to the other this shouldn't be a problem.

Ideally you won't want any optical slave modes to he active if using a radio system, and so avoid any pre-flash triggering issues. Presumably by not setting any wireless mode on your old flashes you will avoid this .....ie setting them as if they were mounted on a camera.

**UncleVanya** · 01-13-2017, 03:50 PM

OK - so the rear flashes are firing at the background from in front of it with their thyristor sensors facing towards the background - correct?

The problem with the Neewer tx/rx triggers is that the 433hz is pretty limiting and the reputation of those triggers is that they misfire a lot. Also they don't have any delay function so I'm not clear if they will fire too soon on the Acon. Really we need clear info on the Acon - will it fire the attached hotshoe trigger on the preflash or on the normal flash?

If it triggers the trigger at the main flash pulse only then I recommend the YN603IIN since it is high voltage safe and cheap ($30 pair) and reliable.

Alternately get the YN560 flashes (a pair) use them manually, and set them on S2. Pivot the bodies to face the front towards the PTTL flashes and then they should see the preflash and fire only when the main flash pulse pops. they would not autoadjust but you can manually adjust them to the right power level which is more than likely the best choice. They are about $60 each new in the latest version.

---------- Post added 01-13-17 at 05:52 PM ----------

Originally posted by mcgregni

The flash output of the manual radio triggered flashes will not interfere with the pre-flashes and metering of the Pentax units, because the pre-flashes and metering occur before the main trigger event ..... The Pentax P-TTL system will not 'see' this light and is unaware of it's existence.

So the Pentax system will deliver it's pre-determined flash exposure regardless ....however, at the point of exposure the additional light will record onto the sensor as additional flash exposure, so you need to take account of that and keep good manual control over the outputs. It sounds like you may be considering the two types of flash light in your scene independently, so unless there is light spill from one part to the other this shouldn't be a problem.

Ideally you won't want any optical slave modes to he active if using a radio system, and so avoid any pre-flash triggering issues. Presumably by not setting any wireless mode on your old flashes you will avoid this .....ie setting them as if they were mounted on a camera.

You are the expert here not me. Does the PTTL Acon pass a fire signal to hotshoe at the preflash or at the main flash time?

mcgregni · 01-13-2017, 04:35 PM

Well I'm no expert on Acon triggers, but from what we have read here I understand them to be 'radio emulators' of a P-TTL cord, effectively. So, in theory, the behaviour of the pre-flashes and triggering timings etc should be exactly the same as with an extension cord set-up ..... Presumably there must be a signal from the hotshoe for the pre-flashes to occur (forwarded by radio between the Acon Tx & Rx), and only after that the main trigger event (ie the actual exposure) occurs. My assumption is that this Main trigger event is the only signal sent via PassThrough to the 2nd radio system on top of the Acon .... ?

stub · 01-13-2017, 04:39 PM

If I was you I'd forget the P-ttl idea, and adopt a manual sytem.. Its far easier to keep control..

mcgregni · 01-13-2017, 05:02 PM

I was actually looking forward to W.j.christy's explanation on how to control the independent P-TTL flash compensations on his two AF-540's from the Acon transmitter ..... This is a confusing area I suspect. The published Acon manual that I have read (the 'morse code guide') is impenetrable to me. I am wondering whether there is any radio control over the P-TTL flash balance or whether this must be controlled directly on the flashes, just like with traditional Pentax cable or wireless operation.

In any case, according to Andy888, there is independent manual group control available from the Tx, so if he prefers the photographer here should be able to switch to full manual exposure control as you suggest stub.

C_Jones · 01-13-2017, 06:43 PM

Shooting in Manual mode hands-on and analyzing test results will yield performance answers itself. The use of optical slave mode will yield results for the user to be able to know if that is effective in either Manual flash or TTL flash modes and also demonstrate if radio triggers are actually required, and if so, in what way/capacity.

Class A · 01-14-2017, 09:13 AM

I wouldn't recommend using the Cactus V6's sensor for optical triggering at a distance. It work well near to a main flash but is too insensitive for long distances.

In general, I support those who suggest to go manual, at least for the two background strobes. An "Auto"-thyristor usage is very unlikely to give you the level of exposure you'll need on the background.

**Ex Finn.** · 01-14-2017, 04:19 PM

Originally posted by Brooke Meyer

bought 4 YN560III's plus a YN560TX

Just got 3 YN 560 IV`s and the YN 560 TX. What an eye-opener in the ease of operation, this is actually fun. I am afraid that I might have caught a bad case of SAS!

Class A · 01-14-2017, 08:30 PM

Originally posted by Ex Finn.

Just got 3 YN 560 IV`s and the YN 560 TX. What an eye-opener in the ease of operation, this is actually fun.

Remote manual control is awesome, isn't it?

Yongnuo cannot be beaten on price but I'd say in terms of useability the Cactus V6 is even more fun to use. The dial allows quick and precise adjustments and the default is to change the power levels of all active groups which is exactly what you want if you need to adjust for a change in aperture or ISO setting.

How does the YN560 TX handle this case?

BTW, individual group adjustments on a V6 are just as quick through pressing the respective group button while turning the dial.

The V6II adds HSS to all that but that comes at a price (not only the higher cost of the V6II but also the P-TTL-induced delay and pre-flashes from non-RF60 flashes).

**Ex Finn.** · 01-15-2017, 06:53 AM

Originally posted by Brooke Meyer

Ok, I give up. SAS?

Speed-light Acquisition Syndrome

**Ex Finn.** · 01-15-2017, 07:21 AM

Originally posted by Class A

The dial allows quick and precise adjustments and the default is to change the power levels of all active groups which is exactly what you want if you need to adjust for a change in aperture or ISO setting.

How does the YN560 TX handle this case?

No global group adjustment, only individual. I can live with that.

01-13-2017, 02:03 PM	#1
W.j.christy Site Supporter Join Date: Oct 2015 Location: Texas Photos: Albums Posts: 558	Old Flashes and Wireless Trigger compatibility Staff note: This post may contain affiliate links, which means Pentax Forums may earn a small commission if a visitor clicks through and makes a purchase. If you would like to support the forum directly, you may also make a donation here. Simply put, I was thinking of using older thyristor flashes (available cheaply in many places) with a simple radio trigger to illuminate the my back round when I take portraits. Typically I use a white back ground and the goal would be to illuminate it enough to blow out and of the details of it (wrinkles, seams etc...) So my thought is to get two older thyrister flashes with a very cheap transmitter receiver combo in conjunction with my ACON RF930's on 2 AF540FGZ's which provide the TTL lighting for the subject. I would place the cheap-o-mitter on top of the 930 transmitter to get everything to fire at the same time. Question is, will it work, specifically will it work with P-TTL preflash.... I worry that the pre-flash will set off the older flashes then I will have lost my back ground illumination. Any thoughts on this? Also given my quest, I was curious if anyone knew of some older flashes that have some amount of power adjustment built in, and have decent power to them. Any thoughts or comments are welcome. Last edited by W.j.christy; 01-13-2017 at 02:09 PM. Reason: text errors

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01-13-2017, 02:32 PM	#2
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,400	I am a novice at this but just started playing in this space. My reading of the cactus v6 trigger docs indicates that you can fire them optically ignoring preflash (they have their own sensor if the flash you pick does not). I would imagine the auto-thyristor part of the equation isn't going to buy you anything - I'm thinking you will want to fire the cheap flash solution on manual so you can avoid having the P-TTL flashes overwhelm the sensor but your placement may make that moot. The P-TTL measured flash may be inaccurate due to the contribution of the cheapie flashes but you can probably dial those down or up as needed via flash exposure compensation. The cactus v6 trigger can control some TTL flashes some of which are not too expensive (for example the SB-24 nikon). The combination of a TTL flash with the cactus gives you pseudo manual control by tricking the TTL flash into thinking it needs to quench exposure at the right moment you can create the same effect as manual supposedly. At the moment I'm only using my Cactus with a dedicated RF60 and a fully manual only AF500FTZ (the AF500FTZ is not compatible with the cactus in TTL mode so I have to set manually on the flash and that flash only goes down to 1/32nd power). The Yongnuo RF602N triggers are cheap and work great on top of the cactus (I have tried this) and will trigger any manual or thyristor flash with a reasonable trigger voltage. The newer RF602 II units I think have better trigger voltage protection. Try searching for cactus flash compatibility to find out more about the TTL pseudo manual control options. It's pretty nice since you can have 4 groups and control them in many different ways right from the camera. ---------- Post added 01-13-17 at 04:34 PM ---------- Also many flashes have various optical slave options to ignore preflash. I'm just not sure how preflash plays on the RF side in terms of triggering. ---------- Post added 01-13-17 at 04:44 PM ---------- I did some more reading. I think that if you put a V6 where it will see the output of the P-TTL lights and set the delay on that one and have it trigger optically not electrically then it can trigger the rear cheap flashes for you ignoring the pre-flash. Does that make sense? There are others here with much more experience and knowledge but this might get the conversation going.

01-13-2017, 02:59 PM	#3
W.j.christy Site Supporter Join Date: Oct 2015 Location: Texas Photos: Albums Posts: 558 Original Poster	Originally posted by UncleVanya I'm thinking you will want to fire the cheap flash solution on manual so you can avoid having the P-TTL flashes overwhelm the sensor but your placement may make that moot. The P-TTL measured flash may be inaccurate due to the contribution of the cheapie flashes but you can probably dial those down or up as needed via flash exposure compensation. Yep this was the goal. The cheapo thyristors would be fully manual with some way on the flash itself to dial down the power. The idea would be to have a 4 light setup. the two AF540FGZ's up front illumination the subject with P-TTL via the ACON trigger/reciever combo, and place the thryristors behind the subject and adjust their output to properly illuminate the background, or overexpose it in the case of the white background. Something like the diagram below ----------------------------------Back Ground--------------------------------------- Thyristor ------------------------------------------------------------------ Thyristor -----------------------------------Subject AF540------------------------------------------------------------------------ AF540 ------------------------------------- Camera My hope is that with the Thyristors behind the subject and away from the background a significant distance the light from the thyristors should not interfere with the P-TTL function of the AF540FGZ's..... I have seen similar set ups in photo studios used for this very purpose, i just haven't played with it yet. I am also trying to keep the cost down to under about 50 bucks, which is the reason for the desire to use old thyristors (like the vivitar 2800) and the cheap 15.00 transmitter/receiver combos from ebay such as this one Neewer 16CH Wireless Remote FM Radio flash Speedlite Trigger w/2.5mm PC Receiver \| eBay. what is considered a reasonable trigger voltage? the neewer says its good for 12v. What flashes work with that number? Any ideas?

01-13-2017, 03:19 PM	#4
C_Jones Pentaxian Join Date: Sep 2012 Location: NY Photos: Gallery \| Albums Posts: 6,084	I have an auto-thyristor that I have not tried with my three AF-360FGZ's. It is Vivitar. I bought it somewhere around 1990 or so to use with my Pentax K-1000 (film). Most likely it has the optical slave option, so I would resort to that if I used it. You may want to test your flashes with the optical option of an auto-thyristor to see if there is some success. Keeping your flashes and camera in Manual mode would most likely allow you to control the output more than utilizing the TTL mode. It looks like you are receiving good advice on your situation. Good luck. Last edited by C_Jones; 01-13-2017 at 03:29 PM.

01-13-2017, 03:41 PM	#5
mcgregni Veteran Member Join Date: Sep 2012 Location: Surrey, England Posts: 2,603	The flash output of the manual radio triggered flashes will not interfere with the pre-flashes and metering of the Pentax units, because the pre-flashes and metering occur before the main trigger event ..... The Pentax P-TTL system will not 'see' this light and is unaware of it's existence. So the Pentax system will deliver it's pre-determined flash exposure regardless ....however, at the point of exposure the additional light will record onto the sensor as additional flash exposure, so you need to take account of that and keep good manual control over the outputs. It sounds like you may be considering the two types of flash light in your scene independently, so unless there is light spill from one part to the other this shouldn't be a problem. Ideally you won't want any optical slave modes to he active if using a radio system, and so avoid any pre-flash triggering issues. Presumably by not setting any wireless mode on your old flashes you will avoid this .....ie setting them as if they were mounted on a camera.

01-13-2017, 03:50 PM	#6
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,400	OK - so the rear flashes are firing at the background from in front of it with their thyristor sensors facing towards the background - correct? The problem with the Neewer tx/rx triggers is that the 433hz is pretty limiting and the reputation of those triggers is that they misfire a lot. Also they don't have any delay function so I'm not clear if they will fire too soon on the Acon. Really we need clear info on the Acon - will it fire the attached hotshoe trigger on the preflash or on the normal flash? If it triggers the trigger at the main flash pulse only then I recommend the YN603IIN since it is high voltage safe and cheap ($30 pair) and reliable. Alternately get the YN560 flashes (a pair) use them manually, and set them on S2. Pivot the bodies to face the front towards the PTTL flashes and then they should see the preflash and fire only when the main flash pulse pops. they would not autoadjust but you can manually adjust them to the right power level which is more than likely the best choice. They are about $60 each new in the latest version. ---------- Post added 01-13-17 at 05:52 PM ---------- Originally posted by mcgregni The flash output of the manual radio triggered flashes will not interfere with the pre-flashes and metering of the Pentax units, because the pre-flashes and metering occur before the main trigger event ..... The Pentax P-TTL system will not 'see' this light and is unaware of it's existence. So the Pentax system will deliver it's pre-determined flash exposure regardless ....however, at the point of exposure the additional light will record onto the sensor as additional flash exposure, so you need to take account of that and keep good manual control over the outputs. It sounds like you may be considering the two types of flash light in your scene independently, so unless there is light spill from one part to the other this shouldn't be a problem. Ideally you won't want any optical slave modes to he active if using a radio system, and so avoid any pre-flash triggering issues. Presumably by not setting any wireless mode on your old flashes you will avoid this .....ie setting them as if they were mounted on a camera. You are the expert here not me. Does the PTTL Acon pass a fire signal to hotshoe at the preflash or at the main flash time?

01-13-2017, 04:35 PM	#7
mcgregni Veteran Member Join Date: Sep 2012 Location: Surrey, England Posts: 2,603	Well I'm no expert on Acon triggers, but from what we have read here I understand them to be 'radio emulators' of a P-TTL cord, effectively. So, in theory, the behaviour of the pre-flashes and triggering timings etc should be exactly the same as with an extension cord set-up ..... Presumably there must be a signal from the hotshoe for the pre-flashes to occur (forwarded by radio between the Acon Tx & Rx), and only after that the main trigger event (ie the actual exposure) occurs. My assumption is that this Main trigger event is the only signal sent via PassThrough to the 2nd radio system on top of the Acon .... ?

01-13-2017, 04:39 PM	#8
stub Senior Member Join Date: Oct 2010 Location: Manchester Photos: Gallery Posts: 227	If I was you I'd forget the P-ttl idea, and adopt a manual sytem.. Its far easier to keep control..

01-13-2017, 05:02 PM	#9
mcgregni Veteran Member Join Date: Sep 2012 Location: Surrey, England Posts: 2,603	I was actually looking forward to W.j.christy's explanation on how to control the independent P-TTL flash compensations on his two AF-540's from the Acon transmitter ..... This is a confusing area I suspect. The published Acon manual that I have read (the 'morse code guide') is impenetrable to me. I am wondering whether there is any radio control over the P-TTL flash balance or whether this must be controlled directly on the flashes, just like with traditional Pentax cable or wireless operation. In any case, according to Andy888, there is independent manual group control available from the Tx, so if he prefers the photographer here should be able to switch to full manual exposure control as you suggest stub.

01-13-2017, 06:43 PM	#10
C_Jones Pentaxian Join Date: Sep 2012 Location: NY Photos: Gallery \| Albums Posts: 6,084	Shooting in Manual mode hands-on and analyzing test results will yield performance answers itself. The use of optical slave mode will yield results for the user to be able to know if that is effective in either Manual flash or TTL flash modes and also demonstrate if radio triggers are actually required, and if so, in what way/capacity.

01-14-2017, 09:13 AM	#11
Class A Pentaxian Join Date: Aug 2008 Location: Wellington, New Zealand Posts: 11,251	I wouldn't recommend using the Cactus V6's sensor for optical triggering at a distance. It work well near to a main flash but is too insensitive for long distances. In general, I support those who suggest to go manual, at least for the two background strobes. An "Auto"-thyristor usage is very unlikely to give you the level of exposure you'll need on the background.

01-14-2017, 04:19 PM	#12
Ex Finn. Site Supporter Join Date: Nov 2007 Location: Southern Maryland. Espoo. Kouvola. Photos: Gallery \| Albums Posts: 7,975	Originally posted by Brooke Meyer bought 4 YN560III's plus a YN560TX Just got 3 YN 560 IV`s and the YN 560 TX. What an eye-opener in the ease of operation, this is actually fun. I am afraid that I might have caught a bad case of SAS!

01-14-2017, 08:30 PM	#13
Class A Pentaxian Join Date: Aug 2008 Location: Wellington, New Zealand Posts: 11,251	Originally posted by Ex Finn. Just got 3 YN 560 IV`s and the YN 560 TX. What an eye-opener in the ease of operation, this is actually fun. Remote manual control is awesome, isn't it? Yongnuo cannot be beaten on price but I'd say in terms of useability the Cactus V6 is even more fun to use. The dial allows quick and precise adjustments and the default is to change the power levels of all active groups which is exactly what you want if you need to adjust for a change in aperture or ISO setting. How does the YN560 TX handle this case? BTW, individual group adjustments on a V6 are just as quick through pressing the respective group button while turning the dial. The V6II adds HSS to all that but that comes at a price (not only the higher cost of the V6II but also the P-TTL-induced delay and pre-flashes from non-RF60 flashes).

01-15-2017, 06:53 AM	#14
Ex Finn. Site Supporter Join Date: Nov 2007 Location: Southern Maryland. Espoo. Kouvola. Photos: Gallery \| Albums Posts: 7,975	Originally posted by Brooke Meyer Ok, I give up. SAS? Speed-light Acquisition Syndrome

01-15-2017, 07:21 AM	#15
Ex Finn. Site Supporter Join Date: Nov 2007 Location: Southern Maryland. Espoo. Kouvola. Photos: Gallery \| Albums Posts: 7,975	Originally posted by Class A The dial allows quick and precise adjustments and the default is to change the power levels of all active groups which is exactly what you want if you need to adjust for a change in aperture or ISO setting. How does the YN560 TX handle this case? No global group adjustment, only individual. I can live with that.