Most cameras set the top flash sync to 1/200th or 1/250th. But the D700 will sync at up to 1/320th. Why? Is there a particular reason why Nikon did this? Just curious....
#1. "RE: Why sync my flash to 1/320th???" | In response to Reply # 0
Powder Springs, GA, USA
Nikonians Team Member
#3. "RE: Why sync my flash to 1/320th???" | In response to Reply # 2
Ask away. I just thought that thread would be a odd starting point. You can squeeze a little more shutter speed out at 1/320. Only 1/3 stops though.
At a speed of 1/320th, the shutter is open long enough to see 90% of the flash burst, so you lose a little. If you had your sync set to 1/250 FP, then FP would be in place at 1/320th and you would lose a lot more than 10%.
Personally, I don't see why Nikon bothered, because we are just talking about 1/3rd of a stop. It lets you shoot at 1/320 without being in FP at virtually full flash power.
Powder Springs, GA, USA
Nikonians Team Member
#4. "RE: Why sync my flash to 1/320th???" | In response to Reply # 3
Both my D700 and D300s truly sync at 1/320th with no loss of frame.
I have found that even 1/400 sec is usable in most conditions, where the lack of flash at the very top of the frame is unnoticable, as in daylight fill, and not using the dedication feature.
Mainly talking about non-dedicated untits, of higher power.
But also the built-in and SB units, up to the 1/320 only if using the dedication.
I may be mistaken, but the original post seems to contain a question about the importance or usefullness of a higher sync speed.
To that subject, photographers who use flash for fill-light in daylight have always wanted the sync speeds of regular ambient sunlit daylight exposures, and the higher the shutter speed, the more open the aperture, and the less flash required for fill. It also freezes motion better, of course.
Regular sun-light daylight exposures for most of the world are equivalent to ISO 200, 1/250 sec, and f16, or 1/500 at f11, and 1/1000 at f8. which aperture is more reasonable to expect from a flash unit at any normal distance. ( Sunny 16 rule, with a bit of less exposure for saturation )
Nikon's D70/s and D50, and D40 all are able to sync from any speed up to over 1/1250, due to their sensors' electronic shutter control, which seems to be only offered on smaller (6 MPX) CCD sensors. I have personally found this higher sync speed to be essential in getting sharp photos of motorcycles at 25 or 30 MPH, in daylight using fill flash to highlight details and expose the shadows. Even 1/320 does not completely eliminate the ambient blur edges of objects moving at higher speeds and flashed. ( Quantum flash unit, on full manual, at 1/4 power, at ISO 200, f8, 1/1000 sec.)
In manual exposure mode, this works well for a consistent sunny day, but under varying cloudy/sunny conditions, especially popcorn clouds, it is helpful to use Aperture priority automation. With a camera limited to 1/320 second sync, you are unable to do this effectively. With the D40 set to A exposure mode, the flash can be synced at f8, ISO 200, and the shutter can float between 1/1200 sec and 1/400 sec, giving sharp, accurate exposure for the subject ( pre-determined distance held constant ) and the background's varying ambient light.
Thus the lowly D40 is PROFESSIONALLY a more suitable tool for this work than the D300 etc. ( 2,500 saleable frames made with this set-up daily for 8 or 9 days straight at typical event = 20,000 clicks ) The shorter shutter life is the trade-off for the extended capability of the D40's higher sync speed, the camera needing several shutter replacements during its useful lifetime.
#5. "RE: Why sync my flash to 1/320th???" | In response to Reply # 4
>Both my D700 and D300s truly sync at 1/320th with no loss of
Not really, hence the two options. To be truly in sync, the shutter must be wide open for the entire duration of the flash. At 1/320 it is not. As Russ points out, the tail of the flash is not captured, hence the guide number is reduced.
This acts against syncing at higher speeds during daylight. Yes, 1/130 lets you open the aperture a bit, but you also lose some flash power which works counter to what you are trying to achieve.
I think it just lets you shoot without FP sync at a real loss of power, albeit you do lose power. The 1/250 standard sync is to ensure that you get full flash power for the shot. Russ does say that you don't get truly full power at 1/250 either, but its very close.
Powder Springs, GA, USA
Nikonians Team Member
#6. "RE: Why sync my flash to 1/320th???" | In response to Reply # 5
Yes really, no matter what you have read or been told by whomever.
If the entire frame is exposed to the flash at the same time, that means it is in sync. I have found the entire frame IS IN FACT exposed by the flash at 1/320. REALLY. That means the D300/S and D700 cameras sync at 1/320. If the flash is faster than the shutter, and it does fire way faster, maybe at 1/1000 to 1/10,000 sec, it is in sync. I have used a flash all day this way, and taken many, many photos in sync at 1/320 with the D300.
"Tail" is not a significant factor. You would rarely be able to notice it. The "tail of the flash" in electronic flash is a minimal loss if you have enough flash power. The exposure of the entire frame without a dark shutter curtain shadow is the essential criteria. You can have the entire frame exposed evenly to the amount of flash light required. If the light has been slightly diminished, and it is an unnoticable amount believe me, you can either increase power, or if at max power already, open the aperture a bit to compensate.
If the flash duration is very long, like a full power monster studio light unit, the flash duration may be longer than a high sync speed, and clipping of the flash may occur, but that is due to the flash duration, not the sync. Even in these instances, the frame will be exposed evenly at 1/320. Out-of-sync is only occurring if the frame is partially shadowed by the shutter curtain. In ambient exposure, this generally has no visible effect*, and in fact is the way the exposure is calculated to give high effective speeds from a limited actual mechanical speed, but when a blitz of near-instantaneous flash hits at above sync speeds, it catches the curtains in the act.
With a Hassleblad's or other leaf shutter lens, at higher speeds like 1/1000 sec., clipping may occur. Clipping does NOT mean out of sync. ( Leaf shutters do not produce shadows at any speed, nor aperture, because they are not at the focal plane, and that's why they sync at all speeds.)
In fact, the sync speed of a focal plane shutter does not even depend on flash at all for its essential definition. A focal plane shutter's sync speed is the highest speed at which the entire frame is open, and not shadowed by any part of the curtain. At speeds higher than the true sync speed, the rear or closing shutter curtain, whether vertically or horizontally running, will already be in front of the frame, on its way to closing, when the front or opening curtain is just all the way open. Or vice-versa, whatever the timing. The front curtain may not yet be all the way open when the rear begins to close. Either way, in effect, at shutter speeds higher than the highest sync speed, the frame is being exposed by a moving slit, albeit very wide at say 1/400, and becoming narrower the higher the speed out-of-sync.
If the flash is doing what you wanted, giving the proper amount of fill flash, or flash main exposure, and the whole frame is exposed to it, it is in sync. We have the "polaroid" chimp screen to check our lighting and adjust.
DO this to prove it to yourself. Take the camera ( D700, or D300, and probably other Nikons that sync at 1/250 and 1/320 )into a fairly dark room, where the ambient light is low enough to give a black or dark frame. Attach any flash on manual, thru the sync terminal, or by a simple center contact hot shoe adapter. Set the shutter on manual to 1/320 sec. Fire the camera and flash at a blank secton of wall, which fills the frame of the camera. Check the exposed frame. It is All exposed, and the same amount of light evenly across the entire frame, (except for whatever edge/corner fall-off the lens may have, but that will occur at all corners, and is not due to sync) Then download the image onto your computer, and look at it..... It's ALL EXPOSED, across the entire frame. You will not begin to see a shutter curtain shadow until at 1/400 sec, and then only a small strip of that shadow at the top. Using increasingly higher speeds will produce progressively wider top shadows, and rob you of more frame coverage.
That is what "in-sync" means. In actual usage. In most cases of daylight fill flash, you can use 1/400 as well, not caring that the small usually invisible strip at the top of the frame is lacking the fill flash, since the subject that needs fill is usually more in the center of the frame, ( persons' heads ) not at the very top which often consists of sky or distant objects that would not return any flash light anyway, and the daylight is lighting the entire frame as well.
Most of the time, even dedicated flash units are not pumping out full power in programmed mode. When they do, an underexposure warning will usually ensue.
* There are photos of speeding race cars from the early 20th century made with slow moving focal plane shutters, ( not flash ), which produce an odd effect of making the tires look ovular, stretched in a diagonal direction .... the moving slit captures the tire at one place in the beginning of the exposure, and by the end of the exposure, the tire has moved forward enough to have its image stretched into an oval on the film. Not a linear stretch in the tire's moving direction, and not vertical, but in a diagonal due to the combined motion vectors of the car and the moving slit of the shutter curtains.
#7. "RE: Why sync my flash to 1/320th???" | In response to Reply # 6
Apologies for the length of the previous post, but I was trying to be clear and precise.
These concepts are long established and widely known, and I have been using them for over twenty years in professional work.
However, it is entirely understandable that photographers who have not used flash other than dedicated units would never be able to see out-of sync effects, nor learn about shutter sync other than within the (Nikon, Canon, etc.) brand's system and instruction lore. Once fully connected, (via shoe) a dedicated SB type of flash and a Nikon DSLR communicate, so the camera will not allow speeds above the sync speed to even be set, not even in the camera's or flash's Manual exposure modes.
#8. "RE: Why sync my flash to 1/320th???" | In response to Reply # 6
You misinterpreted what I said. The flash is in sync to the extent that the flash covers the entire frame at 1/320. It is not in sync to the extent that 10% of the flash pulse is lost, so you lose guide number. Ultimately it is probably about a 1/6 stop difference.
You have a light gain of 26% at the extra 1/3 stop, but you lose 10% of the flash power for about a 16% light gain. I seriously doubt that Nikon would program standard vs FP syncs at 1/250 and 1/320, if standard sync at 1/320 did not suffer the GN loss. There would be no reason for it.
Powder Springs, GA, USA
Nikonians Team Member
#9. "RE: Why sync my flash to 1/320th???" | In response to Reply # 8
I understood exactly what you said, and addressed it in the long post.
Your problem is you are talking about clipping, not about sync.
The 1/6 stop is not a significant factor compared to the higher speed it affords. Also, the loss can be compensated by more power, higher ISO, or aperture adjustment, but the sync speed is a mechanical limitation. Be sure you understand the virtues of having the highest sync speed possible.
Like I said, the clipping is not a sync phenomena, but a flash duration one. The figure of 1/6 of a stop is based on a particular flash unit, whatever model it is, at a particular power ratio, and is not some universal factor. The clipping factor (tail, % etc.) would change with different flashes, and at different output levels/durations. Just changing to a different flash does not change or define the mechanical properties of the camera itself. Also keep in mind that the last 1/6 of flash power is rarely used in the programmed iTTL flash sytem usage. Thyristor circuits conserve energy not needed, and keep it to extend battery life.
Rest assured that Nikon understands sync, and if they are dumbing down their explanations and programming for the sake of the greater market, that is understandable. The actual professional market is too small for a camera company to survive on.
#10. "RE: Why sync my flash to 1/320th???" | In response to Reply # 9
For a flash to be fully "in synch", its burst of illumination needs to start and complete within the time that the shutter is fully open. I believe that is a well-established photographic principle.
#11. "RE: Why sync my flash to 1/320th???" | In response to Reply # 10
If you want to use that definition of sync, even at 1/250 the camera/flash is not fully in sync, as stated in the previous post #5 of this thread.
It's a matter of degree, yes, but still in principle, not fully in sync at 1/250, by such a definition.
The well-established photographic principle of sync is not that the full flash duration has to be captured, but the usable majority of flash power is captured across the full frame.
Cameras used to have M sync. , for disposable focal plane flash bulbs. The flash bulb burn time was relatively long, and the camera shutter speed required to capture the entire flash duration would be too long for a sharp picture, so M sync was a calculated exposure time that captured the majority of the flash power, and clipped the slow start up and tail burn of the flashbulb.
Phillips, a manufacturer of flash bulbs, produced a bulb PF100E, that had a full bell curve of flash duration taking 1/14 sec, or 70 milliseconds, and gave the M-sync requirement of 1/50 second. They listed x-sync at a mere 1/25 of a second, if that terminal was used on the camera. Different bulb models would have different curves and burn stats, but even then there were slight production tolerance variations in a package of bulbs. These old cameras did not have menus, but separate terminals that were used to plug into, M and then later added an X terminal. This major supplier to the photographic industry was allowing for the clipping of the shoulders of the bell curve as an accepted loss. http://www.flashbulbs.com/Philips_ph-5.htm
Electronic flash durations are vastly faster, and their tails and start-up burn times are so insignificant, that they have allowed the focal plane shutters to go way faster and remain in sync.
What about the electronic sensor high-speed sync of a D40 ?
If 1/320 clips some some power of the flash, the speed of 1/1000 sec will clip even more. Yet that sync speed is usable, and will allow flash exposure of the entire frame on a D40. The electonics shut down the exposure at 1/1000 sec. even though the shutter's top mechanical sync speed is 1/200. It works because the flash duration is even shorter. The majority of flash duration of most flash units at 1/4 power is faster than 1/1000 sec., regardless of the shoulders of the curve.
If one insists on a technically irrelevant definition, the real-world usage will continue, and the only loss is to those that may otherwise benefit by the full use and understanding of the capabilities of their equipment.
#12. "RE: Why sync my flash to 1/320th???" | In response to Reply # 0
#14. "RE: Why sync my flash to 1/320th???" | In response to Reply # 12
Brian aside from the discussion of what "sync" means, don't both Scott and Al make valid points on the use of high sync settings? Scott points out that because the tail is cut off you lose some power and Al points out that you still get a fully illuminated image, with no curtain shadow. I would think both viewpoints are useful to someone trying to get the best out of their equipment despite the differences in semantics. I do agree that the topic would be a better discussion point over in the Speed lights and Lighting Forum, but I did find the exchange interesting.
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#15. "RE: Why sync my flash to 1/320th???" | In response to Reply # 14
>Brian aside from the discussion of what "sync"
>means, don't both Scott and Al make valid points on the use of
>high sync settings?
Absolutely, and it has been very interesting!
Such discussions are not D700-specific and the subject would attract a wider audience and additional participation in the Speedlights Forum.
#16. "RE: Why sync my flash to 1/320th???" | In response to Reply # 15
You can cut up a tomato any way you want, but besides belonging in the Speedlight Forum, I think it is useful information that is very suitable and pertinent to the D700 forum. The question about sync originated here, because the D700 owner thought to ask here first.
The answers may have expanded beyond expectations, but are relevant to the original question.