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D600 and Pocket Wizard Flex Mini TT1 and TT5... totally compatble?


twmeyer

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<p>Just got one of each (TT5 and Mini TT1) and after updating firmware and resetting to factory defaults, I've discovered it works great with my D700, all the way to 1/2000 sec, but only works up to 1/320 with the D600 and then I start to see cutoff at higher speeds. Sound familiar? No? (sigh) <br /><br />Thanks... t</p>
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<p>The key to optimizing PocketWizard's so-called <em>HyperSync</em> (i.e., shooting at shutter speeds above x-sync, without any visible curtain-shadow) is to employ strobes with long t=0.5 values. I complied a list of popular strobes with long flash durations here:</p>

<p>http://www.photo.net/photography-lighting-equipment-techniques-forum/00bIAI</p>

<p>Reportedly, the Nikon D800/E fares even better than Nikon D3-series bodies, and I've been able to observe this extra margin of performance in my own informal tests. Unfortunately, it appears from your observations that Nikon's D600 may not have inherited these properties. Note that HyperSync performance is highly variable, depending on the particular body being used.</p>

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<p>So the key is finding a SLOW flash @full power ie, the longest fraction of a sec and a camera that...what?</p>

<p>Triggers the flash to 'start' at the first shutter blade movement and not when the first shutter arrives at the far side?</p>

<p>This kinda implies the trigger point is <em>different</em> with different Nikon FX DSLRs...I never knew that. I thought that was fixed!</p>

<p>Just curious, but if I fire my flash manually at full power whilst filming it with my Nikon V1 @ 400 fps, if I get more than one frame illuminated, that means it's <em><strong>slow</strong></em><strong> </strong>and therefore suitable for PW Hypersync flash??</p>

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<p>Mike said:</p>

<blockquote>

<p><em>So the key is finding a SLOW flash @full power ie, the longest fraction of a sec and a camera that...what?</em></p>

</blockquote>

<p>Yeah . . . I dunno. I don't fully understand why different DSLRs perform differently, even among the same brand. I only know that longer t=0.5 values exploit this effect best, and that the highest usable sync speeds vary from model to model. My admittedly limited knowledge on this subject comes only from my own casual tests, a small amount of published information from other photographers, and from other photo.net members here (perhaps some of whom will chime in).</p>

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<p>Long post below but I hope it can be of some help clearing up what happens behind the scenes which can help when trouble shooting.</p>

<p><strong>REGULAR X SYNC</strong><br /> DSLRs have two shutter curtains. Before the exposure the front curtain is closed and the back curtain is open.</p>

<p>1. At the start of the exposure the front curtain will start to open. <br /> 2. When the front curtain is fully open the x contact is activated. That triggers the flash.<br /> 3. At the end of the shutter time the rear curtain will start to close.</p>

<p>The maximum x sync speed is the shortest shutter speed when there still is enough time for the flash to burn before the camera starts to close the rear curtain. But how long is enough time for the flash to burn? How big is the margin? Well, that's up to the camera engineers to decide. When they say that the flash sync speed is 1/250s or 1/200s there is an unknown amount of leeway.</p>

<p>If you use a short flash duration you can sync at slightly higher speeds without getting into trouble.<br /> When you use a "dumb" radio trigger to fire the flash, there will be a small delay from the time the x contact is triggered to the time the flash fires. That means that we may need to sync at a slower shutter speed when using radio triggers without getting into trouble.</p>

<p>When TTL capable pocketwizards (PWs) are used on a compatible camera the radio trigger now has more information about the shutter process and can fine tune the point in time where the radio message is sent. Because of that the TTL PWs can compensate for the delay that the radio triggers normally would add and also fine tune the starting point further so you can get even higher flash sync speeds than before.</p>

<p><strong>AUTO FP MODE / HIGH SPEED SYNC</strong></p>

<p>But we come to a point where the shutter speed is so short that the front curtain hasn't even opened fully yet before the rear curtains begins to close. This is the point where the camera normally would trigger the flash in Auto FP mode (auto focal plane or flat peak, aka high speed sync).</p>

<p>This works by pulsating the flash very, very fast so there is not enough time for the flash tube to stop emitting light. Basically we are now turning the flash into a continuous light source, like a regular tungsten light.</p>

<p>So instead of triggering the flash after the front curtain has opened we now have to trigger the flash before the entire exposure takes place so the flash can illuminate the scene throughout the exposure. This only works with flash that can support this mode, currently just speedlights and the new Profoto B1 monolight - as far as I know.</p>

<p>The procedure is now:<br /> 1. Turn on the flash in continuous light mode.<br /> 2. Start the exposure by starting to open the front curtain.<br /> 3. At the end of the shutter time start to close the rear curtain (the opening between the curtain is now a slit).<br /> 4. The front curtain has opened completely.<br /> 5. The rear curtain has closed completely.<br /> 6. Turn off the flash.</p>

<p>Keep in mind that the shutter curtains always move at the same speed regardless of the shutter speed. So a short shutter speed doesn't mean that the SPEED is faster - it means that the TIME it takes before closing the shutter is shorter.</p>

<p><strong>HYPERSYNC</strong><br /> <br />Then we have Pocketwizards Hypersync mode. It's nothing new. It was called FP sync for use with flat peak flash bulbs before electric flash was used. The FP contact would be triggered just before the exposure start and the flash bulb would burn all the way through the exposure. Just like the example above.</p>

<p>Modern cameras don't have the FP sync connector anymore but there is a workaround for that. Users of dSLRs that had AutoFP mode would put a speedlight on the camera, have Auto FP activated and then use an optical trigger to get the FP sync signal that way instead. If you were in a studio you could just trigger your strobes directly with the light from the on-camera speedlight. Or you could use an optical trigger to trigger a radio transmitter for extended range applications.</p>

<p>The TTL PW's Hypersync mode works the same but uses the TTL communication in the hotshoe to determine when the exposure actually starts and get the FP sync signal that way. Then it's also possible to fine tune that time back and forward in time. Since electronic strobes are more powerful at first you will get more even exposure if the first peak of light from the flash tube comes before the sensor in the camera starts to be exposed. Best strobes for this application is those that have long flash duration times.</p>

<p>What we are doing with hypersync is the same as FP sync except that we are not turning the flash tube into continous light with pulsing, rather we are using the strobes longer flash duration.</p>

<p>Speedlights usually has a very short flash duration except at high power. That is because the power of the flash unit is controlled by cutting of the power to the flash tube. So if the poweer is set at 1/128 the flash duration is a lot shorter than if it's set to full power. A transistor called IGBT is used to cut the power and some strobes use that technique as well, for instance the Einstein 640.</p>

<p>If you can't get a D600 (or any other camera) to sync at higher than 1/320 you are likely not in hypersync mode. The pocketwizards will automatically go from one mode to another depending on the shutter speed. With the right settings of course both on the camera and on speedlights and the PWs.</p>

<p> </p>

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Sorry. The Flex CTL system from

pocket wizard is supposed to interface

with the Nikon CLS system, which

actually strobes their SB900 rapidly in

order to achieve the "slow" burst of

light required for hypersync. I get it, I

understand the process.

 

What I need to know is, why is the

D700 capable of this with CLS (Nikon

system) and CTL (Pocket Wiz system),

while the D600 is compatible with CLS

(Nikon), but *not* CTL ( PW)?

 

Or am I just missing some tweak in

custom settings or PW software?

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"So the key is finding a SLOW flash @full power ie, the longest fraction of a sec..."

 

For almost all monolights (with a couple of exceptions, the Einstein E640 being the best known) the flash duration at low

power is longer than at full power. It has to do with how they control how much electricity is released to the flash tube.

 

With Speedlights and the E640 and now the Profoto B1 monolights the reverse is true.

 

With Speedlights in HSS /FPS mode the flash is sending out a stream of low powered flashes that track with the

movement of the gap between the front and rear shutter curtains.

 

Why do different cameras even in the same make have different characteristics? Because the shutters and electronics

controlling them are different.

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<p>Just to add to some of the things that Pete S wrote above. FP sync has never stood for 'Flat Peak', but simply for 'Focal Plane' - FP sync merely means a type of synchronisation designed for use with Focal Plane shutters.</p>

 

<blockquote>

<p>"This only works with flash that can support this mode, currently just speedlights and the new Profoto B1 monolight - as far as I know."</p>

</blockquote>

<p>Not strictly true. FP synchronisation itself does not rely on an electronic flash going into pulse mode. It's really a change in the camera timing, and doesn't necessarily involve a change in the flash at all. In fact it was originally designed so that flashbulbs (remember them?) could be used with focal-plane shuttered cameras, e.g. Leicas, way back in the 1920s.</p>

<p>The only slight fly in the ointment is that whereas in old film cameras we could select FP mode manually; Nikon have now seen fit to only allow FP synch when one of their expensive speedlights (or a 3rd party clone or specialised trigger gizmo) is fitted to the hotshoe. Auto-FP just means that FP synch is automatically selected when a shutter speed above the X-sync speed is selected <em>and</em> the camera has an FP enabling device in the hotshoe.<br>

However, the system can be fooled by having an FP-synch enabling device in the hotshoe, but then adding another flash via the P-C socket. The P-C socket always follows the triggering from the hotshoe, and can therefore be used to add a 'normal' flash to the light from the hotshoe speedlight. Indeed, if the speedlight is pointed away from the subject it's light output can be made to have a minimal contribution.</p>

<p>This trick allows a high shutter speed to be used with almost any old flash - provided the flash duration is long enough and constant enough to cover the entire time of the shutter travel, from first blind opening to second blind closing. In Nikon's recent DSLRs, that travel time is approximately the same as the maximum X synch speed; i.e 1/320th or 1/250th, depending on the camera model. So if any electronic flash has a duration of 1/250th of a second, then it can be used in FP mode.</p>

<p>I've used this method myself to get synch speeds of up to 1/8000th with old Metz hammerhead flashes and with studio strobes; although in practise you'll probably find that shutter speeds above around 1/2000th will stretch the lighting ability of the flash .</p>

 

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<p>Yeah, I should have mentioned what strobe I was dealing with, even though I was referencing the Nikon CLS system... my tests were done with an SB900, but I also use SB800 flashes, too. This is how I am able to get high speed sync with both the D700 and the D600, using Nikon CLS. I have not gone to PW tech support yet.<br /><br />My primary concern is to make the MiniTT1 work with my Einsteins, which I have done, and then to make the AC3 work with the Einsteins... *then* I'll start sweating the D600-SB900/800 connections work. <br /><br />I have priorities, and in my line of work, the Einsteins are currently primary... t</p>
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<p>Tom, <br>

Perhaps this is obvious but have you checked that the Flash sync speed on the D600 is correct? Custom setting e1 should be set to <strong>1/200s (Auto FP)</strong> on the D600 - <strong>not</strong> 1/250s (Auto FP).</p>

<p>Rodeo Joe,<br>

Nice clarification on the FP sync. It makes sense to talk about the sync as separate from the mode of the flash when it tries to emulate slow burning FP flash bulbs. <br>

The P-C socket is not electrically connected with the center pin in the hotshoe anymore. So some newer cameras can disable the PC sync output in certain modes where the hotshoe is still working. The same applies to the P-C socket on the speedlights. For instance when a speedlight is in wireless CLS mode it will not fire the pc sync output.</p>

 

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<p>Yeah, you're welcome :-)</p>

<p>I just thought it was a good idea to see how it went. You know, the next poor guy who has the same problem as you did will search the web in vain looking for the same solution. Without your post he would have to keep looking. Now just reading the posts in this thread he will find out that the flash sync speed setting on the D600 is indeed the problem.</p>

 

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