# 5D3 Second Curtain Sync - Design Flaw?



## gbchriste (Sep 8, 2012)

I've got an event coming up where I need to use a couple of off camera 430EX II flashes fired with Cyber Sync triggers. The setup also will require second curtain synch, which I've never used before. So I've been sitting here going through my 5D3 menus trying to set second curtain synch and just discovered that the only way to do that is to have a powered-on Canon flash mounted on the camera. If you don't have a Canon flash attached and turned on, you can't access the menu to set the shutter synchronization. 

Now, I just confirmed that if I attach the flash, set the shutter synch, then dismount the flash and hook it up to my Cyber Sync trigger, the second curtain sync that was previously set will work as expected. I have all camera settings on manual and and as as test, set the shutter to 6 seconds and the flash did indeed fire just before the shutter closed. Then I remounted the flash on the camera, entered the menus and set it back to first curtain synch, dismounted the flash back to a off-camera manual setup, and this time it fired when the shutter opened.

So there is a way to get there. But this obviously is not workable if you need to toggle between first and second curtain sync when using a manual off-camera flash setup, which I may need to do in this situation.

Am I missing something? Is there a way to set the flash curtain synch without having the flash physically connected to the camera and powered on?


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## DJL329 (Sep 8, 2012)

As a work-around, how about setting two of the C# settings, one for each configuration?


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## bigmag13 (Sep 8, 2012)

you may have to set the sync on the 430's and leave them as is ( they stay at the settings when powered off and back on). I havent tried it with 430's. I am so used to walking over to them or setting the functions on the flash that this has never occurred to try it. It may also be the riggers. I have never noticed the lack of that setting when using PW's.


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## risc32 (Sep 9, 2012)

i do off camera lighting all the time. I didn't know there was a workaround to not having the option of rear curtain synch, but honestly i've never needed it. how is it that you know in advance that you are going to be needing to fire two off camera flashes with rear curtain synch? i'm not trying to be a smart ass, i'm rather good at that says the wife, i've just honestly shot lots of weddings and other events and this has never been an issue. probably just shooting shooting something cool with movement that i haven't. also i think i use the same triggers that you are using, but i've gotten to the point where i really only use them for triggering the shutter, and i use the PITA Canon light based master/slave system. I know, it sucks, but i've gotten rather good at operating it quickly and it's nice to have such fine(1/3 stop) adjustments. i'm currently looking at another system...


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## gbchriste (Sep 9, 2012)

DJL329 said:


> As a work-around, how about setting two of the C# settings, one for each configuration?



I'd already given that some thought and that's certainly an option but it seems pretty stupid if Canon is restricting this option solely to configurations that employ a Canon flash. Was there never any thought that Canon body users might be using some other non-Canon flash system and want to employ second curtain synch?


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## gbchriste (Sep 9, 2012)

bigmag13 said:


> you may have to set the sync on the 430's and leave them as is ( they stay at the settings when powered off and back on). I havent tried it with 430's. I am so used to walking over to them or setting the functions on the flash that this has never occurred to try it. It may also be the riggers. I have never noticed the lack of that setting when using PW's.



I think you missed the point. Even though my units are Canon 430EX II flashes, the shot envisioned is a 100% manual, off camera, multi-flash set up. So ideally I'd be able to select second curtain flash from the camera menu because the shot set up is going to have the flashes on stands several yards away from me. I don't want to have to mount the flash on the camera for the sole purpose of putting the camera in to second curtain sync mode.


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## gbchriste (Sep 9, 2012)

risc32 said:


> i do off camera lighting all the time. I didn't know there was a workaround to not having the option of rear curtain synch, but honestly i've never needed it. how is it that you know in advance that you are going to be needing to fire two off camera flashes with rear curtain synch? i'm not trying to be a smart ass, i'm rather good at that says the wife, i've just honestly shot lots of weddings and other events and this has never been an issue. probably just shooting shooting something cool with movement that i haven't. also i think i use the same triggers that you are using, but i've gotten to the point where i really only use them for triggering the shutter, and i use the PITA Canon light based master/slave system. I know, it sucks, but i've gotten rather good at operating it quickly and it's nice to have such fine(1/3 stop) adjustments. i'm currently looking at another system...



I don't mind. I'm a fairly advanced natural light portrait shooter - though not a novice with off camera flash. I've used my Canon 430EX IIs off camera with Cyber Syncs quite a bit. The daughter of one of my dearest friends in the world is getting married in a couple of weeks and the photographer they booked backed out on them. They are desperate and on a tight budget. They came to me begging me to do the wedding. I've been the second shooter on a couple and that was all it took to convince me that I don't want to do weddings.

I've tried multiple times to convince them that I'm not a wedding photographer but they just won't let up on me. So I finally buckled and agreed to do it. One of the conditions was that the bride and her mom come up with the shot list ahead of time and I will work off that list and only that list - no ad libing. They'll give it to me a week a head of the wedding so I have time to plan - and if necessary, practice - each shot.

One of the things she's asked for are some special effects shot with sparklers, like this:

http://www.sparklersonline.com/blog/www-sparklersonline-com-3/wedding-sparkler-photo-tutorial/

Reading through that tutorial, the shot calls for second curtain sync. And I am familiar enough with flash photography to understand why that is the preferred technique.


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## Mt Spokane Photography (Sep 9, 2012)

gbchriste said:


> The setup also will require second curtain synch, which I've never used before.


And, so You posted a subject title that is picked up by search engines, and now spread all over the internet based on your expert finding?


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## gbchriste (Sep 9, 2012)

Mt Spokane Photography said:


> gbchriste said:
> 
> 
> > The setup also will require second curtain synch, which I've never used before.
> ...



Not sure I understand your point. I don't have an "expert finding". I have a shot that I'm not familiar with in mind that I need to execute that, based on immediately available info, may require second curtain sync with a manual, off-camera flash setup. I may discover between now and then that I don't need second curtain sync. But if it turns out I do, I'd like to be able to accomplish that without going through the logistics of putting a flash on the camera just to access the second curtain sync menu. My specific question was whether anyone else was aware if mounting the flash was actually a requirement to access the second curtain sync menu without first mounting a Canon flash on the camera. 

BTW, I am a software engineer by training and trade and from a software engineering and man-machine interface design view point, it seems utterly ridiculous and short sighted to design the menu system with such an obvious limitation in it, if in deed this is the case. And that IS an expert (i.e. me) finding.


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## bigmag13 (Sep 9, 2012)

gbchriste said:


> bigmag13 said:
> 
> 
> > you may have to set the sync on the 430's and leave them as is ( they stay at the settings when powered off and back on). I havent tried it with 430's. I am so used to walking over to them or setting the functions on the flash that this has never occurred to try it. It may also be the riggers. I have never noticed the lack of that setting when using PW's.
> ...



K. It just may not be a feature or function with your triggers. I don't have my 3 here ( it's at the Jamesburgh service center for calibration with my 16-35) to test that out, but I do think it's the trigger not allowing or having access to that feature in the menu.
I will test the PW's with the 5D2 to see if they allow it tho. gimme 15mins.


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## Mt Spokane Photography (Sep 9, 2012)

gbchriste said:


> Mt Spokane Photography said:
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The point is simple, you are calling it a design flaw, when the flaw is perhaps lack of experience.
Perhaps asking why it is not possible would be a good title, but declaring a design flaw?? 
Since you are a software engineer, and hopefully, a good one, doesn'y it annoy you when someone who has never used your software before suddenly declares a design flaw, rather than asking how it was designed to work?
If they want to do something else with your software, that might be of value to them, but was not part of the design, it the software buggy?


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## gbchriste (Sep 9, 2012)

bigmag13 said:


> gbchriste said:
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No mystery there. The Cyber Sync system is a 100% manual-only radio trigger. The only function it provides is flash firing. No ETTL, no control of flash settings from the camera, etc. So as far as the camera is concerned, there are no flashes in the setup when the Cyber Sync trigger is mounted in the hot shoe.


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## bigmag13 (Sep 9, 2012)

bigmag13 said:


> gbchriste said:
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Nope, no flaw. It doesnt allow that choice with PW's on my 5D2. which reminds me that I have always kept them in 2nd sync when on stands at receptions, lol. it freezes the dance floor. going crazy at a very young age here!


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## gbchriste (Sep 9, 2012)

Mt Spokane Photography said:


> gbchriste said:
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> 
> > Mt Spokane Photography said:
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More often than not, when I have an annoyed user, it's because the user has some insight in to how the software should operate, based on their knowledge and experience with the application domain, that I didn't have and didn't take in to account when designing the software. Usually I didn't ask the right questions or probe deeply enough in to their requirements, and the optimal working of the function in question seems so obvious to them that they didn't think it required mentioning. 

The design makes absolutely no sense, at least to me. You can't put the camera in to second curtain sync without attaching a Canon flash. So it would seem that Canon's intent is that function should not be operative unless the flash is in fact attached. But I have already proven via trials that once the second curtain sync is set, I can turn off the camera, remove the flash, connect the flash off camera to a "dumb" radio trigger that has no communication with the camera, turn everything back on, and have the second curtain sync operate as envisioned. So if it was Canon's intent that this feature only operate in tandem with a Canon flash, why doesn't it default back to first curtain sync when the flash is removed from the Camera?

I am a good software engineer. At some point there was a design discussion over what text to put on the LCD menu that informs the user they can't access that menu because there is no compatible flash attached (that's what it does). I hope that if I'd been in the design loop I would a question along the lines of, "Hey, what if someone wants to use that function with a non-Canon flash, like maybe Elinchroms or Bowens?"


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## bigmag13 (Sep 9, 2012)

gbchriste said:


> Mt Spokane Photography said:
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not jumping on you dude, just saying that it was answered... the triggers just dont do it! it's not the camera that syncs, it sends a signal to the flash to flash twice. I think that's an Electrical Engineers realm tho. I could be wrong tho.


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## gbchriste (Sep 9, 2012)

bigmag13 said:


> gbchriste said:
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> > Mt Spokane Photography said:
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Actually, I sort of get what drove the design decision, although I don't agree with it. The "Flash Function Settings" menu includes five features - Manual vs ETTL, Zoom, Exposure Compensation (ETTL only), Power (Manual only), and curtain synch.

All of those except curtain synch obviously require some intelligent communication between the camera and flash and so it makes sense that you wouldn't present those to the user in the absence of a compatible flash. But the last one - curtain sync - doesn't require any intelligent communication between the camera and the flash. The only thing required to make that work is to send the firing signal to the hot shoe or sync cable at the right time, either just after opening the first curtain or just before closing the second curtain.

So it's possible that the designers just found it more convenient to keep that last option together with the others to avoid having to make more space in the menu system.


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## dmills (Sep 9, 2012)

This isn't so much related to the 5d3, as just a workaround to the shot you're wanting. The point of the second curtain is to fire right before the shutter closes. Since this is a long-exposure shot that you're wanting to stage, and it will be in bulb mode, you know when the shutter is going to close. You could always just manually fire your flashes right before you end the exposure.


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## rpt (Sep 9, 2012)

gbchriste said:


> Actually, I sort of get what drove the design decision, although I don't agree with it. The "Flash Function Settings" menu includes five features - Manual vs ETTL, Zoom, Exposure Compensation (ETTL only), Power (Manual only), and curtain synch.
> 
> All of those except curtain synch obviously require some intelligent communication between the camera and flash and so it makes sense that you wouldn't present those to the user in the absence of a compatible flash. But the last one - curtain sync - doesn't require any intelligent communication between the camera and the flash. The only thing required to make that work is to send the firing signal to the hot shoe or sync cable at the right time, either just after opening the first curtain or just before closing the second curtain.
> 
> So it's possible that the designers just found it more convenient to keep that last option together with the others to avoid having to make more space in the menu system.


I agree. Second curtain synch is a function of the camera and not the flash. It should have been in the camera menu and not in the flash menu that is not displayed when flash is not detected.

I think they took a shortcut.


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## TrumpetPower! (Sep 9, 2012)

I haven't yet needed anything other than first-curtain flash with the 5DIII so I haven't gone looking for it. But I couldn't quite believe that the only way to get to it was by attaching a Canon-branded flash...so I just pulled out my 5DIII, and, sure enough, no way to set first- or second-curtain flash.

This is a bug, plain and simple -- and one that Canon really should fix in the next firmware release. As others have mentioned, first- or second-curtain flash isn't some sort of exotic function that requires special communication with a proprietary flash, it's something basic that dates back to the earliest days of electronic flash and works just fine with even the dumbest possible of PC or hotshoe flashes. If I didn't already own a 580 and thus have a workaround available, I'd be really pissed to learn about this.

b&


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## kaihp (Sep 9, 2012)

TrumpetPower! said:


> This is a bug, plain and simple -- and one that Canon really should fix in the next firmware release.


+1

Either not in the requirements, or not designed right.


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## BumpyMunky (Sep 9, 2012)

gbchriste said:


> One of the things she's asked for are some special effects shot with sparklers, like this:
> 
> http://www.sparklersonline.com/blog/www-sparklersonline-com-3/wedding-sparkler-photo-tutorial/
> 
> Reading through that tutorial, the shot calls for second curtain sync. And I am familiar enough with flash photography to understand why that is the preferred technique.



I don't think you actually need 2nd curtain for these shots. Second curtain prevents things like tail-light streaks from going through cars when doing long exposure w/flash of moving cars (or of any movement where direction is important), but for the sparkler thing, when the flash happens isn't that important as long as you know when it will flash.

Both pictures in that article actually appear to be done first curtain to me. Otherwise, (with the first one) they'd need to have written the word backwards to be at the front when the (2nd curtain) flash fired (or use an assistant to write after the pose, but before the flash). What I think they did was pose for the shot with a lit sparkler, open the shutter (with 1st curtain flash), and then wrote the word, closing the shutter (w/o flash) at the end. The second pic doesn't matter so much, as it could have been done both ways:
With 1st curtain: pose, open(flash), mess with sparkler, close(no flash). 
With 2nd curtain: open(no flash), mess with sparkler, pose, close(flash).

If there is too much ambient light, the poses would need to be held throughout the exposure, with assistants doing the writing. If flash is the only light on subject, they only need to be in position for the flash part of the exposure.

I'd probably shoot these with first curtain. It just seems easier. Keep in mind that some subjects (most, in my experience) have no idea what a long exposure is, and associate the sight of a flash as being 'the picture'. It can help to let them know what you're doing so they 'perform' when needed, and not spoil the shot.

(BTW, I agree that hiding the curtain controls from non-Canon flashes is silly)


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## rpt (Sep 9, 2012)

kaihp said:


> TrumpetPower! said:
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> 
> > This is a bug, plain and simple -- and one that Canon really should fix in the next firmware release.
> ...


You in software too?


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## davidbellissima (Sep 9, 2012)

I can highly recommend the Phottix Odin triggers. From the unit on the camera you can set rear curtain sync, high speed sync, TTl or Manual, control the flash output in 1/3 stop increments and zoom the flash head. Fantastic. Here is a link comparing them to some other triggers:

http://www.bellissimaphoto.co.uk/photographers/pocket-wizard-versus-phottix-odin-versus-radio-popper-flash-triggering.html


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## And-Rew (Sep 9, 2012)

So let me get this right -

you're saying that you cannot set up 2nd curtain sync on a 5D3 unless you have a Canon flash attached?

If that is correct, then in my book that is a design flaw or implementation flaw.

I've been using a variety of flash guns at (Nikon, Canon, Metz, Sunpak) Strobist shoots on my 5D2's for 3 years and have always been able to access the flash menu to change curtain sync between 1st and 2nd. A variety of triggers have been used as well.

So glad I decided not to invest huge amounts into the 5D3. Sorry all you techies of this forum - I've been able to access my flash menu on all Canon SDLR's since the 30D and the removal of that option to me is a design flaw.

I'm with the OP


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## kaihp (Sep 9, 2012)

rpt said:


> kaihp said:
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Close, but no cigar. Used to design ICs, before turning to the dark side (ie: management).


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## zim (Sep 9, 2012)

Maybe the guys from Magic Lantern could squeeze in a quicker fix than Canon are likely to do?

I can set first/second shutter on my 500D without a flash so I wonder if this really is a ‘flaw’ or sales/marketing dept. having there way again.


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## gbchriste (Sep 9, 2012)

And-Rew said:


> So let me get this right -
> 
> you're saying that you cannot set up 2nd curtain sync on a 5D3 unless you have a Canon flash attached?
> 
> ...



Actually, it hadn't occurred to me until I read your post that attaching a non-Canon flash might also grant access to second curtain sync. Like you, I've spent some time in the Strobist community and have an LP120 manual flash so I attached it to the camera. Still no go.

Any attempt to access the "Flash function settings" menu, which is where curtain sync is buried, is greeted with a message that reads, "This menu cannot be displayed. Incompatible flash or flash's power is turned off." Same behavior with a remote firing trigger mounted in the hot shoe.

So yes, setting second curtain sync, and turning the sync back to first curtain, cannot be accomplished unless there is a Canon branded flash attached. 

Although I can't test it, I will grant that using some type of 3rd party trigger system that preserves the Canon camera-to-flash communication protocol, like the Pocket Wizard FlexTT5, might enable that portion of the menu system.


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## willhuff.net (Sep 9, 2012)

Any chance that pestering Canon will get them to change it?


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## danski0224 (Sep 9, 2012)

I soooo want the 5DIII, but reading stuff like this changes my mind...

5DII is safe for now.


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## CharlieB (Sep 9, 2012)

I don't think this is a design flaw.

Either by way of direct mounting, or coupled external flash (cable, wireless), there needs to be an TTL flash "known" by the camera.

The reason, I believe, is due to the nature of the 2nd curtain synch. Although the curtain travel time is very fast, at some flash output settings - which are tube firing time derived - you will probably get some unwanted consequences. 

Put another way, 2nd curtain synch actually occurs BEFORE the 2nd curtain begins to move. But how much before? It depends on how long the flash tube is going fire in order to achieve what the "camera/flash" system believe are correct exposure. This may be splitting hairs, but on larger units, the flash tube firing time can be just under 1/1000 second, and no doubt Canon has accounted for this timing factor by limiting the way 2nd curtain synch is implemented.

Moreover... I would not be surprised that if you first set the camera to 2nd curtain, and then went with a non-TTL remote setup, that the camera might "say" its on 2nd curtain, but actually has reverted to first curtain. I can see Canon doing that.


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## Meh (Sep 9, 2012)

@CharlieB I believe he has said he verified that second curtain sync is maintained after he removed the Canon flash. However, I tend to agree with you that it is reasonable that the flash system would have to be known/recognized/compatible before any advanced functions/settings beyond simple triggering would become available. Not that it must be that way but more because from a design perspective Canon would want to test and verify performance of the system before making certain settings available. If they made every setting available for any attached flash system and something didn't work correctly image the screaming they'd be dealing with. Perhaps the software designers have more insight into the potential issues in supporting third party devices that haven't been fully tested and may not comply with the system design. Let's not forget that third party flashes are reverse engineered (I believe so anyway) to be "compatible" and therefore are often not fully compatible.

I'm not saying that second curtain sync is difficult to implement or that it should be restricted when attaching third party flashes/triggers only that Canon decided to turn off the flash control menu for all flash functions if a non-Canon (or non-compatible, non-recognized, non-tested) is attached. Could be for good reasons or just business reasons to encourage sales of Canon flashes.


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## TrumpetPower! (Sep 9, 2012)

CharlieB said:


> Either by way of direct mounting, or coupled external flash (cable, wireless), there needs to be an TTL flash "known" by the camera.



No, there doesn't. Second-curtain sync is much, much older than any form of TTL; it's as old as electronic flashes, period.

The problem with high-speed sync is due to the speed the shutter curtains travel, not due to the flash duration. All flash durations are much shorter than the fastest of shutter curtains. When you shoot at a speed faster than your flash sync, what happens is that the flash pulse has shot its wad while one of the pokey shutter curtains still hasn't cleared the sensor.

With a slow shutter speed, the one curtain completely moves out of the way of the sensor, the flash signal is sent, the curtains remain stationary for the duration of the exposure, and then the second curtain covers the sensor. With second-curtain sync, all that happens is that the flash signal is sent just before the second curtain starts to close rather than jut after the first curtain has finished opening.

With a fast shutter speed, faster than the rated sync speed, the shutter speed is shorter than the time it takes the curtain to get out of the way. So, even before the first curtain has fully cleared the sensor, while only a partial slit of the sensor is exposed, the second curtain already starts to close and chase the first sensor. Again, the flash is fired as soon as the first curtain has fully cleared the sensor...but much of the rest of the sensor is already obscured by the second curtain that's hot on the heels of the first.

High-speed sync gets around that problem with some sort of precision-timed jiujitsu that fires the flash multiple times while the curtains are only exposing part of the scene. How, exactly, the engineers figured out how to do that in a way that doesn't look weird is beyond me...but they did manage to pull it off.

And TTL metering is completely unrelated to curtain travel. These days, I think it's mostly accomplished by some sort of high-speed preflash, but there've been so many other sorts of methods used that I wouldn't quote me on that.

Cheers,

b&


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## CharlieB (Sep 9, 2012)

Meh said:


> @CharlieB I believe he has said he verified that second curtain sync is maintained after he removed the Canon flash.



I took that to mean its maintained in the menu system... wasn't sure if it was actually doing 2nd curtain.

Well aware of all complexities with flash synch... you simply cannot have the start of 2nd curtain travel coincide with the synch. Synch has to be slightly before 2nd curtain travel begins, and it needs to be enough before that, so that the flash has finished firing before the curtain has covered any of the film gate (sensor gate?).

Not talking HHS here, but good ol' X synch. Doing a bit of research.... curtain travel time, complete traverse at X synch speed of 1/250 sec, is about 3.5milliseconds, or... 3.5/1000ths of a second. Clearly, if a longish flash duration of 1/1000 sec is called for, we're gonna have a curtain that is about 1/3 of the way across the sensor when the flash stops firing - IF - the synch is at the beginning of 2nd curtain travel. Therefore, actual 2nd curtain synch is really "near 2nd curtain" synch, whereas, the synch must occur with at least as much time before 2nd curtain travel, as it takes for the flash itself to fire, and to allow for any systemic delays.

So... I'd say, someplace at least around 1/1500th of a second before actual 2nd curtain movement, you've got 2nd curtain synch, which insures that a long duration (not HSS) flash is fully extinguished prior to the shutter actually starting to close. 

How Canon handles that... speculative, but... its not unreasonable to think they take it into account, and vary the actual synch in relation to the 2nd curtain movement, based on the predicted flash firing time (not HSS).
As we know, with conventional flash photography, the flash duration, not impulse power, determines the effective flash exposure. The flash is made to fire for shorter times as less "power" is needed.

As far as I know, there is no 2nd curtain synch for HSS, they're mutually implementable modes of operation.


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## Mt Spokane Photography (Sep 9, 2012)

And-Rew said:


> I've been using a variety of flash guns at (Nikon, Canon, Metz, Sunpak) Strobist shoots on my 5D2's for 3 years and have always been able to access the flash menu to change curtain sync between 1st and 2nd. A variety of triggers have been used as well.


On my 5D MK II and all my other Canon cameras, if I do not have a Canon COMPATIBLE flash attached, I do not get the speedlight functions, just a error message.
However, I do not need a Canon branded flash or trigger, just one that is compatible.
Are you really able to access the speedlight functions with a nikon Flash attached?


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## gbchriste (Sep 9, 2012)

Meh said:


> @CharlieB I believe he has said he verified that second curtain sync is maintained after he removed the Canon flash. However, I tend to agree with you that it is reasonable that the flash system would have to be known/recognized/compatible before any advanced functions/settings beyond simple triggering would become available. Not that it must be that way but more because from a design perspective Canon would want to test and verify performance of the system before making certain settings available. If they made every setting available for any attached flash system and something didn't work correctly image the screaming they'd be dealing with. Perhaps the software designers have more insight into the potential issues in supporting third party devices that haven't been fully tested and may not comply with the system design. Let's not forget that third party flashes are reverse engineered (I believe so anyway) to be "compatible" and therefore are often not fully compatible.
> 
> I'm not saying that second curtain sync is difficult to implement or that it should be restricted when attaching third party flashes/triggers only that Canon decided to turn off the flash control menu for all flash functions if a non-Canon (or non-compatible, non-recognized, non-tested) is attached. Could be for good reasons or just business reasons to encourage sales of Canon flashes.



I have verified that the second curtain sync setting is maintained and applied after removing the flash from the camera. I went as far as powering everything down, removing the flash from the camera, attaching the flash to a "dumb" radio trigger (fire signal only), then powering up the camera. I set the shutter at 6 seconds so I could clearly detect whether the flash was firing on first or second curtain. It was clearly firing on the second curtain, just tiny but perceptible instant before the shutter closed.

My intent was never to have any of the flash intelligence maintained here for ETTL, power, zoom, etc. I just want a plain and simple "fire the flash now" signal sent to the hot shot. From there my Cyber Sync trigger fires the remote flash. 

I have all that working exactly the way I need and want it. I just don't get why the only path there is via having a Canon flash attached to the camera to start the set up.


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## Meh (Sep 9, 2012)

gbchriste said:


> Meh said:
> 
> 
> > @CharlieB I believe he has said he verified that second curtain sync is maintained after he removed the Canon flash. However, I tend to agree with you that it is reasonable that the flash system would have to be known/recognized/compatible before any advanced functions/settings beyond simple triggering would become available. Not that it must be that way but more because from a design perspective Canon would want to test and verify performance of the system before making certain settings available. If they made every setting available for any attached flash system and something didn't work correctly image the screaming they'd be dealing with. Perhaps the software designers have more insight into the potential issues in supporting third party devices that haven't been fully tested and may not comply with the system design. Let's not forget that third party flashes are reverse engineered (I believe so anyway) to be "compatible" and therefore are often not fully compatible.
> ...



All any of us can do is speculate and the speculation that has been given is that your 5D3 does not recognize your trigger as "compatible" and therefore the flash settings menu is not available. Right or wrong, good reasons or bad, like it or not, that is the most likely explanation.


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## And-Rew (Sep 10, 2012)

Mt Spokane Photography said:


> And-Rew said:
> 
> 
> > I've been using a variety of flash guns at (Nikon, Canon, Metz, Sunpak) Strobist shoots on my 5D2's for 3 years and have always been able to access the flash menu to change curtain sync between 1st and 2nd. A variety of triggers have been used as well.
> ...



The shoot scenarios were TFP based shoots with Flickr based Strobist groups using:

'Nikon' based RF602's for firing multiple flashes of varying makes in manual mode
'Canon' based RF602's/3's for firing multiple flashes of varying modes in manual mode
Pocket Wizards of varying kinds etc...
Some cheap PW variety of triggers.

In all cases, I just went into the menu and found the curtain synch mode and changed from 1st to 2nd, and 2nd to 1st. In the heat of a TFP strobist shoot where my allocated time to work with a particular model in a particular location is limited to about 5 minutes - I did not make notes - but I do remember doing everything extremely quickly and on only a few occasion did I attach an actual flash to my 5D2 body.

As has been said - why is a curtain synch menu option a Speedlite dedicated feature? I was using both options on my Canon A1 and Sunpak flash back in '87, so can not see the need of a Speedlite sub menu unless working with a dedicated Speedlite flash?


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## Studio1930 (Sep 10, 2012)

I agree that the option should be available even when a flash is not mounted since you may be using a remote flash (with a basic trigger). Older Canon cameras allowed this and for good reason (lots of photographers used it without a flash or canon trigger mounted).

Cannon needs to put that option back in the menu system full time. Now I need to go check my 1DX and see if it is missing the same option.


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## Quackator (Sep 10, 2012)

gbchriste said:


> Reading through that tutorial, the shot calls for second curtain sync.



Not for me. You want the flash to fire when they are in their final position.
What is wrong with starting 1st sync in that final position (and thus be sure 
about the exact posing and point in time when triggering) and then double use
the flash as signal to the couple to start light painting?

With 2nd sync you have to hope that the couple is in a perfect position after 
exactly six seconds (or whatever your exposure is). With 1st sync you *know* 
that they are.


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## TrumpetPower! (Sep 10, 2012)

CharlieB said:


> How Canon handles that... speculative, but... its not unreasonable to think they take it into account, and vary the actual synch in relation to the 2nd curtain movement, based on the predicted flash firing time (not HSS).



If that's what Canon is doing, then it is, indeed, unreasonable.

Second-curtain flash has worked fine for decades without trying to cut it as close to the wire as possible. Presumably, the timing is based off some sort of standard flash duration. If the curtain happens to still be open for a fraction of a microsecond after the flash extinguishes, that's never been a problem in real-world shooting. Similarly, I've never heard of a real-world problem with the second curtain closing too soon -- and, if that did happen because you were using a really, really slow flash, you'd presumably know enough about your exotic equipment to cut the power a bit.

Whatever the reason for this bug, it is a bug, and inexcusable.

Cheers,

b&


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## Mike6158 (Jun 22, 2014)

Old post I know but I'm about to do a shoot with the 5DMKIII and 4 or 5 strobes in remote locations and I couldn't find the second curtain synch custom function. It looks like the answer is that there isn't one, it's in the menu system, and once it's set with the speedlight mounted the setting remains on 2nd curtain synch. 

There are a bunch of threads about this scattered throughout the net. Most of them have a few "never used it, don't need it" comments. I've never tried it. I can see where it would be handy and I hope that it works for me upcoming setup. I got the idea from a Joe McNally video. 2nd curtain synch is his default setting. If it's good enough for him I suppose it'll do for me.

And yes- it's a design flaw...


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## Mike6158 (Jun 22, 2014)

gbchriste said:


> Now, I just confirmed that if I attach the flash, set the shutter synch, then dismount the flash and hook it up to my Cyber Sync trigger, the second curtain sync that was previously set will work as expected.



I'm not sure why but this is not the case with my 5DMKIII and Pocket Wizards. Once I pulled the 650EX-RT off camera it returns to first curtain synch.


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