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Sync Speed, High Speed Sync, and HyperSync™ http://paulcbuff-techforum.com/viewtopic.php?f=8&t=67 |
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Author: | Technical Support [ Tue Dec 22, 2009 4:15 pm ] |
Post subject: | Sync Speed, High Speed Sync, and HyperSync™ |
Sync speed, as described in a separate thread, is a physical limitation of the camera's shutter. In a low light environment, the flash durations are fast enough to freeze motion, thus a faster shutter speed is not beneficial. To circumvent the shutter limitation, and achieve entire frame exposure of flash, camera manufacturers designed their brand of flashes and cameras to communicate with each other. The camera tells the flash to fire multiple times (or one longer time), to ensure any part of the frame covered by the shutter at one part of the exposure gets evenly exposed by the flash during another part of the exposure. This works fairly well. However, with no lunch being free, there are some drawbacks. First is a reduction in effective power, since the same amount of power has to be divided up. Second is the need for more expensive and dedicated flashes, with less power than a similarly priced mono light. Manufacturers of some newer remote controls have started tapping into the camera/flash communications. This is allowing users to alter how/when their cameras trigger studio lights. Photographers are now able to fire studio lights early, and rely on the "slow" burntime of studio lights to achieve faster flash durations (think- a short lived continuous light). This is known as "HyperSync™" technology in the Pocket Wizard line. Again, the cost of this lunch is lower effective power and potentially uneven lighting, as the power drops over the duration of the burn and different parts of the frame will be exposed to different power levels. Additionally, the effects are likely to change from one shutter speed to another. (***Edit for additional info***>>>) The effects can also vary depending on flash model to flash model (those with longer flash durations being more sucessful), power setting to power setting, as well as camera model to camera model. None of these truly change the x-sync speed of the camera. TS |
Author: | ClaudeJ1 [ Sat Dec 26, 2009 3:05 pm ] |
Post subject: | Re: Sync Speed, High Speed Sync, and Hyper Sync |
This necessitates the use of Radio Poppers or the Pocket Wizard TT-5 units to work around the mechanics of these shutters. The Pocket wizards TT-5 units work well with all the Buff lights using their high speed sync. mode. Tested in the sunshine by moi. They work best with the Zeuss lights because you still need f/22 at a reasonable distance if you use a box, but even an AB 400 will work if it's close enough to the subject. |
Author: | Joseph S. Wisniewski [ Thu Jan 07, 2010 3:36 pm ] |
Post subject: | Re: Sync Speed, High Speed Sync, and Hyper Sync |
Claude has got things a bit mixed up. No production CMOS sensor camera from Nikon, Canon, or Sony has ever used a sensor capable of electronic shutter operation. Neither did any production Foveon sensor. I used the Foveon F7X3-C9110 sensor in an industrial camera I designed. I assure you, the leaf shutter we used (because the camera had dual sensors and a beam splitter) imposed objectionable constraints on the design operation of the camera, and if it were possible to do without it, we certainly would have. The Foveon FX17-78-F13 CMOS sensor used in the Sigma DP-1 and DP-2 is also quite incapable of snap shutter operation. The DP-1 and SP-2 have high sync speeds because they use leaf shutters. There are numerous pictures available of torn down DP-1 and DP-2 cameras that confirm this, and the data sheets for the F7X3-C9110 and FX17-78-F13 can be downloaded from Foveon. Nikon did use electronic shutter CCD (not CMOS) sensors in their D1, D70, D50, and D40 cameras (that is why Paul's people used a D40 for their sync speed experiments). Canon used an electronic shutter CCD sensor in their original 1D. No one currently uses electronic shutters, for two very good reasons.
It is these very real reasons, poor high ISO and dynamic range, poor handling of blown highlights, that camera makers avoid snap shutters. There was not some shadow conspiracy of "crippling mechanical shutters of the last millenium for proprietary and planned obsolescence purposes". The original Hasselblad/Foveon DFinity used snap shutters because it was a three sensor beam splitter camera. That is one of the reasons the design failed. The other reasons were the well documented optical constraints imposed by the beam splitter design.
There was little demand for a system where lenses had to be used at small apertures, and you could not shoot wide angle shots (the widest wide angle available for the system functioned as a longish normal), as well as the color accuracy issues of a dichroic beam splitter system, and the dynamic range, high ISO, and blooming issues of a snap shutter system. Bye bye DFinity, bye bye snap shutters in medium format gear, totally. |
Author: | purdyd [ Sat Jan 09, 2010 9:26 am ] |
Post subject: | Re: Sync Speed, High Speed Sync, and Hyper Sync |
This is allowing users to alter how/when their cameras trigger studio lights. Photographers are now able to fire studio lights early, and rely on the "slow" burntime of studio lights to achieve faster flash durations (think- a short lived continuous light). This is known as "Hyper Sync". We have always been able to trigger the flash early by tricking the camera into thinking it is attached to a flash in high sync mode. In that mode, the sync signal occurs a msec or so before the first curtain opens and continues to be low after the rear curtain closes. Given a suitably long duration flash (approx 4msec) like a speedlight on full power, you can have the flash on during the entire duration of the sensor being exposed. yes, it will uneven, but since this technique is most often used to balance bright ambient light background with a foreground subject, it is still very useful. So if you can control the delay from when the camera puts the sync signal low to when the flash is triggered, you can can optimize this affect. So the real question is, will there be an option to adjust the delay in firing the flash using cybersyncs? David |
Author: | Technical Support [ Mon Jan 11, 2010 5:51 pm ] |
Post subject: | Re: Sync Speed, High Speed Sync, and Hyper Sync |
David, please elaborate on the technique referenced here, as i am not aware of it. As well, is this doable for most cameras? "We have always been able to trigger the flash early by tricking the camera into thinking it is attached to a flash in high sync mode" |
Author: | purdyd [ Mon Jan 11, 2010 8:26 pm ] |
Post subject: | Re: Sync Speed, High Speed Sync, and Hyper Sync |
please elaborate on the technique referenced here, as i am not aware of it. As well, is this doable for most cameras? I know it works for Nikon cameras and from reading on the internet, Canon. Can't speak for other brands. Here is a nice discussion: http://www.flickr.com/groups/strobist/d ... 362003933/ Basically if you have a camera with a focal plane shutter and it has a high sync speed (HSS) mode. You put a flash on the camera that is HSS capable and then dial the shutter speed up until it exceeds the sync speed. You trigger the real flash using the PC port. When the camera goes into the HSS mode, the PC sync signal occurs a couple of milliseconds before the first curtain opens and continues well after the second curtain closes. If you use this PC sync signal to trigger a flash and it has a suitably long duration (like a studio strobe or speedlight on full power) you will have light during the duration when the curtains are exposing the sensor. This technique works best if you can introduce a delay in triggering the flash and hence RF triggers work very well. By controlling the delay and syncrhonizing the flash with the curtains, in theory, you could optimize this affect. In what I think is a rather perverse thing, a Nikon D40, which has essentially an unlimited sync speed does not work in this mode and when you use a RF trigger it becomes limited by the delay in the RF trigger. While a camera with a focal plan shutter like a D300 which has a max sync speed of really around 1/400, (although you can only set 1/320) actually benefits from the delay in RF triggers using this HSS hack. And the very fast and nice cybersync system may actually be too fast to get the most out of this HSS hack. Here is a sequence I shot with a D300, top series normal shoe mount SB800 full power middle series SB800 triggered through the PC sync port with a skyport system last series 1/500 and 1/1000 with the HSS sync hack and the last one 2650.jpg is full 1/2 power with flash on camera |
Author: | ClaudeJ1 [ Tue Jan 12, 2010 2:03 pm ] |
Post subject: | Re: Sync Speed, High Speed Sync, and Hyper Sync |
Joseph S. Wisniewski wrote: Claude has got things a bit mixed up.Apparently so I hear you on this one. It's the main reason I got an 8mm Sigma fisheye for the Foveon and it was a pain trying to correct rectilinears
No production CMOS sensor camera from Nikon, Canon, or Sony has ever used a sensor capable of electronic shutter operation. Neither did any production Foveon sensor. I used the Foveon F7X3-C9110 sensor in an industrial camera I designed. I assure you, the leaf shutter we used (because the camera had dual sensors and a beam splitter) imposed objectionable constraints on the design operation of the camera, and if it were possible to do without it, we certainly would have.Industrial cameras are never used in the sun on an engagment session or Wedding, but are very cool nonetheless The Foveon FX17-78-F13 CMOS sensor used in the Sigma DP-1 and DP-2 is also quite incapable of snap shutter operation. The DP-1 and SP-2 have high sync speeds because they use leaf shutters. There are numerous pictures available of torn down DP-1 and DP-2 cameras that confirm this, and the data sheets for the F7X3-C9110 and FX17-78-F13 can be downloaded from Foveon.Well than, that's what I get for assuming they would carry the original Foveon's perfromance benefits in their entirety (I have owned 3 of them at $25,000 each and still have one. I shall not err in the future by checking the tech specs fist and not assuming anything. I make no sweeping proclamations about shutters Nikon did use electronic shutter CCD (not CMOS) sensors in their D1, D70, D50, and D40 cameras (that is why Paul's people used a D40 for their sync speed experiments). Canon used an electronic shutter CCD sensor in their original 1D. No one currently uses electronic shutters, for two very good reasons.
It is these very real reasons, poor high ISO and dynamic range, poor handling of blown highlights, that camera makers avoid snap shutters. There was not some shadow conspiracy of "crippling mechanical shutters of the last millenium for proprietary and planned obsolescence purposes". The original Hasselblad/Foveon DFinity used snap shutters because it was a three sensor beam splitter camera. That is one of the reasons the design failed. The other reasons were the well documented optical constraints imposed by the beam splitter design.
There was little demand for a system where lenses had to be used at small apertures, and you could not shoot wide angle shots (the widest wide angle available for the system functioned as a longish normal), as well as the color accuracy issues of a dichroic beam splitter system, and the dynamic range, high ISO, and blooming issues of a snap shutter system. Bye bye DFinity, bye bye snap shutters in medium format gear, totally. |
Author: | Luap [ Thu Jan 14, 2010 12:35 am ] |
Post subject: | Re: Sync Speed, High Speed Sync, and Hyper Sync |
purdyd wrote: This is allowing users to alter how/when their cameras trigger studio lights. Photographers are now able to fire studio lights early, and rely on the "slow" burntime of studio lights to achieve faster flash durations (think- a short lived continuous light). This is known as "Hyper Sync". We have always been able to trigger the flash early by tricking the camera into thinking it is attached to a flash in high sync mode. In that mode, the sync signal occurs a msec or so before the first curtain opens and continues to be low after the rear curtain closes. Given a suitably long duration flash (approx 4msec) like a speedlight on full power, you can have the flash on during the entire duration of the sensor being exposed. yes, it will uneven, but since this technique is most often used to balance bright ambient light background with a foreground subject, it is still very useful. So if you can control the delay from when the camera puts the sync signal low to when the flash is triggered, you can can optimize this affect. So the real question is, will there be an option to adjust the delay in firing the flash using cybersyncs? David This can be made to work, but you end up using only a tiny chunk of the available flashpower. This what Radio Popper does. True HHS does about the same thing . . . it stretches out the flash duration, prefires it, then uses a little chunk. At least a dedicated true HHS system has control over how long the flash duration must be to maximize its power at a given exposure time. Either way you end up with very little usable flashpower (a couple of WS) or a big dark to light gradient across the frame if you time it to get any significant power. OK for shooting water drops, but IMHO, of no value for sports unless you want to run around the court three feet from the guy you're shooting :shock: I don't personally buy this tricky method. If I want full, or nearly full flash output at up to about 1/1600 sync speed I would use my D40 or get a G11 and settle for the compromise caused by the CCD sensor. No adjustable delay for CyberSync on the horizon - you would have to delay the camera - not the flash - very complex and you still end up with little flashpower. |
Author: | purdyd [ Thu Jan 14, 2010 11:26 pm ] |
Post subject: | Re: Sync Speed, High Speed Sync, and Hyper Sync |
This can be made to work, but you end up using only a tiny chunk of the available flashpower. This what Radio Popper does. True HHS does about the same thing . . . it stretches out the flash duration, prefires it, then uses a little chunk. At least a dedicated true HHS system has control over how long the flash duration must be to maximize its power at a given exposure time. Either way you end up with very little usable flashpower (a couple of WS) or a big dark to light gradient across the frame if you time it to get any significant power. contrast the upper right hand corner, normal high speed sync with the left hand bottom corner, hacked high speed sync OK for shooting water drops, but IMHO, of no value for sports unless you want to run around the court three feet from the guy you're shooting :shock: I don't personally buy this tricky method. If I want full, or nearly full flash output at up to about 1/1600 sync speed I would use my D40 or get a G11 and settle for the compromise caused by the CCD sensor. no, you won't get full power flash from a D40 at 1/1600 sync speed unless your full power flash is faster than 1/1600 in duration also, notice in the above sequence you actually get a dark frame at 1/1000 when you use a regular RF trigger because the delay robs time that the flash should be firing when the curtains are open - and the cybersyncs will do the same, they will rob power from the flash but notice the hacked 1/1000 frame dsc2649 is not dark No adjustable delay for CyberSync on the horizon - you would have to delay the camera - not the flash - very complex and you still end up with little flashpower the heavy lifting has already been done by the camera companies, they have a delay built in when you put a FP capable flash on them thanks for your honesty and directness on this capability, it makes my future buying decisions easier |
Author: | Luap [ Fri Jan 15, 2010 1:08 am ] |
Post subject: | Re: Sync Speed, High Speed Sync, and Hyper Sync |
http://www.paulcbuff.com/forums/viewtop ... f=2&t=6176 AB400 (or even 1600) is much faster than SB800. CyberSync has less sync delay than Skyport or most other radio trippers. Notice these shots lost only .45f of available flash power with D40 and AB 400 at 1/1600, and .9f at 1/2000, with CyberSync (1/4000 sec CS delay). Without CS you would probably see no loss at 1/1600 and little loss at 1/2500 sync. |
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