anyone use rear sync on cactus 6ii.....getting 2 flashes vs 1

Aaron28 · 03-09-2020, 06:43 PM - **1 Like**

was trying for rear/second curtain sync using cactus v6ii TX (latest pen FW) but for some reason it flashed at the beginning and the end of the exposure versus the end which was my intent......the flash was af200fg on a v6 (RX latest FW)…..be nice to get the single flash at the end of the exposure

**stevebrot** · 03-09-2020, 09:29 PM

Trailing curtain sync on Pentax is done under P-TTL and requires a pre-flash...

...though only the second flash should happen when the shutter is open. ~~What body are you using? What shutter speed? Self-timer?~~ Click through to Flickr for details...

I just read @Aaron28 's review of the V6 and obviously, he is more conversant on the subject first hand...so shut up we do...

Steve

Aaron28 · 03-09-2020, 09:59 PM

the v6ii has a function for rear sync that is selectable reckon it's courtesy of the pen firmware because it is not available with the x-ttl FW...….

filler>>>>(I know wirelessly with 2 af360s switched to 2nd curtain it does the preflash before exposure and primary flash at the end and I did not use af360)….

more filler>>>used af200fg on a v6...(no problems with 1/180 or slower HSS off, rear sync not engaged)…

when rear sync is set on v6ii top sync speed is capped at 1/90.....

problem>>>>seems the v6ii is maybe doing the same but the preflash is part of the exposure...…

Originally posted by stevebrot

What body are you using? What shutter speed? Self-timer?

was using the K-1 at 1second.....no self timer

morenjavi · 03-10-2020, 03:56 AM

Originally posted by Aaron28

when rear sync is set on v6ii top sync speed is capped at 1/90.....

Some points on my part, but maybe I'm not a big expert on rear curtain. I think BruceBanner is more 'tanned' with cactus triggers.

Limit on 1/90 when you select rear curtain is normal, you get the same limit with other pentax flashes or triggers, 1/90.
With PTTL, getting a preflash at the beginning of the exposure I think it's normal, you get the preflash at the beggining, and the real flash at the end of the exposure.
Can the second exposure be just ambient light exposure? What are your settings on ISO/speed... are you registering ambient light too? This can explain the double exposure (ambient + flash).

I still have a V6II and a V6, if I had time I could try to reproduce your settings later. Could you describe your settings for the pic on post #1? triggers and flashes used, settings on camera, etc ? Thanks.

Roadboat24 · 03-10-2020, 07:17 AM

Aaron28. I tried your setup (K1, V6ii on camera, V6 RX with AF540fgzii). Acted as you state. tried with K3 and K50, same thing, tried with V6ii receiver, same thing. Everything I tried, could not get Rear Sync to work. Read through this ( 2nd curtain Sync ? Cactus Community ). I did get rear sync to work with a V6ii transmitter and a RF60X receiving flash in both TTl and manual. otherwise, no go. Disappointing. (Firmware, V6ii PEN.A.005, V6 V61.A.003, RF60X A.08)

**stevebrot** · 03-10-2020, 09:38 AM

I know...I was going to stay quiet, but I noticed something interesting about the example. There are three ghost images, rather than two. Longer exposures of action can be deceptive in that if the subject stops for an instant, that instant becomes a ghost.* Are you sure both discharges happened after the shutter opened? A good test is to use the 2-second self-timer. The preflash will fire at the beginning of the timing with the main flash firing at the end (hopefully with the trailing curtain). Perhaps it is time to reproduce under controlled conditions?

Steve

* I have this happen all the time with white water shots between 1/2s and 1/10s.

Aaron28 · 03-10-2020, 03:49 PM

Originally posted by stevebrot

.so shut up we do...

never! I appreciate and value any input you have steve.....you have helped me with a variety of issues maybe more so than anyone else on PF that I can readily think of

Originally posted by stevebrot

There are three ghost images, rather than two. Longer exposures of action can be deceptive in that if the subject stops for an instant, that instant becomes a ghost.* Are you sure both discharges happened after the shutter opened? A good test is to use the 2-second self-timer. The preflash will fire at the beginning of the timing with the main flash firing at the end (hopefully with the trailing curtain). Perhaps it is time to reproduce under controlled conditions?

i'm fairly confident that I am getting both 'preflash' and 'rear flash' exposures but of course not 100%......yes some more 'testing' is necessary as I really want use of this function although given the environment it will mostly be done in I may hafta resolve to the 360/540fgz wireless mode which has worked a charm in the past.....

Originally posted by Roadboat24

Aaron28. I tried your setup (K1, V6ii on camera, V6 RX with AF540fgzii). Acted as you state. tried with K3 and K50, same thing, tried with V6ii receiver, same thing. Everything I tried, could not get Rear Sync to work. Read through this ( 2nd curtain Sync ? Cactus Community ). I did get rear sync to work with a V6ii transmitter and a RF60X receiving flash in both TTl and manual. otherwise, no go. Disappointing. (Firmware, V6ii PEN.A.005, V6 V61.A.003, RF60X A.08)

thank you for your time in running through the motions....stinks that it resulted the same......the link is super helpful !!! seems that they can't address the issue as the v6ii is maxed out FW wise (that's what I understood).......it did seem someone had success with a K-3 but your results say otherwise...…

I am going to try a few things but it seems the best work around in regards to a long exposure (prolly a 1/2 second or more) is to cover the lens prior to the "preflash" and uncover after it has flashed for the remaining exposure resulting in only the rear flash getting recorded....which won't be all that bad considering the things I want to "get" will prolly be 1 second or more but very disappointing for other fun stuff that would benefit from proper rear sync...…

with the v6 have had some success using the delay to get a pseudo rear sync but was not consistent....(the delay time equaled exposure time).....may try it with the v6ii

Aaron28 · 03-10-2020, 03:58 PM

Originally posted by morenjavi

I still have a V6II and a V6, if I had time I could try to reproduce your settings later. Could you describe your settings for the pic on post #1? triggers and flashes used, settings on camera, etc ? Thanks.

K-1.....v6ii latest pen FW set to rear sync......1 sec.....fa43..f5.6 or 6.3?.....100iso....

v6 latest FW.....af200fg......using af360 profile and is responsive every time I use it with a v6.....not so much with v6ii the hss stuff whacks it out

Aaron28 · 03-10-2020, 08:37 PM

another example where you can see the flash in her glasses both times

03-09-2020, 09:29 PM	#2
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,004	Trailing curtain sync on Pentax is done under P-TTL and requires a pre-flash... ...though only the second flash should happen when the shutter is open. ~~What body are you using? What shutter speed? Self-timer?~~ Click through to Flickr for details... I just read @Aaron28 's review of the V6 and obviously, he is more conversant on the subject first hand...so shut up we do... Steve Last edited by stevebrot; 03-09-2020 at 10:01 PM.

03-10-2020, 07:17 AM	#5
Roadboat24 Pentaxian Join Date: Jul 2017 Posts: 372	Aaron28. I tried your setup (K1, V6ii on camera, V6 RX with AF540fgzii). Acted as you state. tried with K3 and K50, same thing, tried with V6ii receiver, same thing. Everything I tried, could not get Rear Sync to work. Read through this ( 2nd curtain Sync ? Cactus Community ). I did get rear sync to work with a V6ii transmitter and a RF60X receiving flash in both TTl and manual. otherwise, no go. Disappointing. (Firmware, V6ii PEN.A.005, V6 V61.A.003, RF60X A.08) Last edited by Roadboat24; 03-10-2020 at 07:22 AM.

03-10-2020, 09:38 AM	#6
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,004	I know...I was going to stay quiet, but I noticed something interesting about the example. There are three ghost images, rather than two. Longer exposures of action can be deceptive in that if the subject stops for an instant, that instant becomes a ghost.* Are you sure both discharges happened after the shutter opened? A good test is to use the 2-second self-timer. The preflash will fire at the beginning of the timing with the main flash firing at the end (hopefully with the trailing curtain). Perhaps it is time to reproduce under controlled conditions? Steve * I have this happen all the time with white water shots between 1/2s and 1/10s. Last edited by stevebrot; 03-10-2020 at 09:44 AM.

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03-09-2020, 06:43 PM - 1 Like	#1
Aaron28 Pentaxian Join Date: Jan 2015 Location: Huntsville, Al Posts: 6,852	anyone use rear sync on cactus 6ii.....getting 2 flashes vs 1 was trying for rear/second curtain sync using cactus v6ii TX (latest pen FW) but for some reason it flashed at the beginning and the end of the exposure versus the end which was my intent......the flash was af200fg on a v6 (RX latest FW)…..be nice to get the single flash at the end of the exposure

03-09-2020, 09:59 PM	#3
Aaron28 Pentaxian Join Date: Jan 2015 Location: Huntsville, Al Posts: 6,852 Original Poster	the v6ii has a function for rear sync that is selectable reckon it's courtesy of the pen firmware because it is not available with the x-ttl FW...…. filler>>>>(I know wirelessly with 2 af360s switched to 2nd curtain it does the preflash before exposure and primary flash at the end and I did not use af360)…. more filler>>>used af200fg on a v6...(no problems with 1/180 or slower HSS off, rear sync not engaged)… when rear sync is set on v6ii top sync speed is capped at 1/90..... problem>>>>seems the v6ii is maybe doing the same but the preflash is part of the exposure...… Originally posted by stevebrot What body are you using? What shutter speed? Self-timer? was using the K-1 at 1second.....no self timer

03-10-2020, 03:56 AM	#4
morenjavi Pentaxian Join Date: Jul 2016 Posts: 522	Originally posted by Aaron28 when rear sync is set on v6ii top sync speed is capped at 1/90..... Some points on my part, but maybe I'm not a big expert on rear curtain. I think BruceBanner is more 'tanned' with cactus triggers. Limit on 1/90 when you select rear curtain is normal, you get the same limit with other pentax flashes or triggers, 1/90. With PTTL, getting a preflash at the beginning of the exposure I think it's normal, you get the preflash at the beggining, and the real flash at the end of the exposure. Can the second exposure be just ambient light exposure? What are your settings on ISO/speed... are you registering ambient light too? This can explain the double exposure (ambient + flash). I still have a V6II and a V6, if I had time I could try to reproduce your settings later. Could you describe your settings for the pic on post #1? triggers and flashes used, settings on camera, etc ? Thanks.

03-10-2020, 03:49 PM	#7
Aaron28 Pentaxian Join Date: Jan 2015 Location: Huntsville, Al Posts: 6,852 Original Poster	Originally posted by stevebrot .so shut up we do... never! I appreciate and value any input you have steve.....you have helped me with a variety of issues maybe more so than anyone else on PF that I can readily think of Originally posted by stevebrot There are three ghost images, rather than two. Longer exposures of action can be deceptive in that if the subject stops for an instant, that instant becomes a ghost.* Are you sure both discharges happened after the shutter opened? A good test is to use the 2-second self-timer. The preflash will fire at the beginning of the timing with the main flash firing at the end (hopefully with the trailing curtain). Perhaps it is time to reproduce under controlled conditions? i'm fairly confident that I am getting both 'preflash' and 'rear flash' exposures but of course not 100%......yes some more 'testing' is necessary as I really want use of this function although given the environment it will mostly be done in I may hafta resolve to the 360/540fgz wireless mode which has worked a charm in the past..... Originally posted by Roadboat24 Aaron28. I tried your setup (K1, V6ii on camera, V6 RX with AF540fgzii). Acted as you state. tried with K3 and K50, same thing, tried with V6ii receiver, same thing. Everything I tried, could not get Rear Sync to work. Read through this ( 2nd curtain Sync ? Cactus Community ). I did get rear sync to work with a V6ii transmitter and a RF60X receiving flash in both TTl and manual. otherwise, no go. Disappointing. (Firmware, V6ii PEN.A.005, V6 V61.A.003, RF60X A.08) thank you for your time in running through the motions....stinks that it resulted the same......the link is super helpful !!! seems that they can't address the issue as the v6ii is maxed out FW wise (that's what I understood).......it did seem someone had success with a K-3 but your results say otherwise...… I am going to try a few things but it seems the best work around in regards to a long exposure (prolly a 1/2 second or more) is to cover the lens prior to the "preflash" and uncover after it has flashed for the remaining exposure resulting in only the rear flash getting recorded....which won't be all that bad considering the things I want to "get" will prolly be 1 second or more but very disappointing for other fun stuff that would benefit from proper rear sync...… with the v6 have had some success using the delay to get a pseudo rear sync but was not consistent....(the delay time equaled exposure time).....may try it with the v6ii

03-10-2020, 03:58 PM	#8
Aaron28 Pentaxian Join Date: Jan 2015 Location: Huntsville, Al Posts: 6,852 Original Poster	Originally posted by morenjavi I still have a V6II and a V6, if I had time I could try to reproduce your settings later. Could you describe your settings for the pic on post #1? triggers and flashes used, settings on camera, etc ? Thanks. K-1.....v6ii latest pen FW set to rear sync......1 sec.....fa43..f5.6 or 6.3?.....100iso.... v6 latest FW.....af200fg......using af360 profile and is responsive every time I use it with a v6.....not so much with v6ii the hss stuff whacks it out

03-10-2020, 08:37 PM	#9
Aaron28 Pentaxian Join Date: Jan 2015 Location: Huntsville, Al Posts: 6,852 Original Poster	another example where you can see the flash in her glasses both times

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