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The Importance of Flash Sync Speed
Ryan at his grandparents.
bigger. Nikon D40, Nikon SB-400 flash, Nikon 35mm f/ane.8 AF-S, P fashion chose f/1/500 at f/13, Auto ISO chose ISO 200, Auto -3 WB.
Sync speed is the fastest shutter speed y’all can apply with wink, period.
Yous cannot use a faster shutter speed than the sync speed with wink. If you try on a camera more than about 20 years old yous’ll get a fractional blackout of the image, and modern cameras override you lot electronically when the flash is on.
A shutter’s rated pinnacle speed is irrelevant because it doesn’t work any faster than the rated sync speed with wink.
Sync speed is important for two big reasons:
1.) The first and obvious reason is that fast sync helps stop move. 1/250 is non what we want and one/125 is out of the question. We need to shoot at 1/500 or faster to cease action.
two.) The second reason, which is rather abstract and often misunderstood, is that faster sync speeds help become plenty flash power to residual with directly sunlight. Make full wink in straight sunlight is critical to getting adept shots in sunlight. This is why you’ll see a flash atop every pro newspaper photographers’ camera. Nature photographers take a heck of a trouble with this, because we shoot at long distances from piffling animals. Information technology’due south tough getting plenty fill on a bird 50 feet abroad, even with those stupid concentrator lenses in front of our flashes. Ditto for using fill for shooting sports through a long lens.
The wink is essentially an instantaneous outburst of brilliant calorie-free. Shutter speed has no outcome on the level of exposure from this instantaneous flare-up. Either the shutter is open or closed at that instant; the time it’s open up has no effect on wink exposure.
Ambient exposure depends direct on the shutter speed. The longer the shutter is open up, the most exposure you go from the ambience (continuous) lite.
The shutter speed changes the ratio of flash to ambient.
Faster speeds have less ambient and the same flash exposure, while longer speeds accept more ambient and the aforementioned flash exposure.
All the other exposure factors (ISO, aperture) impact both flash and ambient equally. (Of form distance affects flash exposure, but that’s not today’s topic.)
The highest speed at which the camera tin can use flash, called the Sync Speed, is the fastest speed at which at that place is an instant during which the shutter is 100% open. This maximum speed defines the largest ratio of flash to ambient lite.
Faster sync lets u.s.a. shoot at larger apertures, which requires less flash power, which lets our flash recycle faster, which lets us shoot more than frames per second.
Directly sunlight is harsh and needs fill, and faster sync lets become enough power from our flash to residue with direct sunlight. We demand even more flash power at slower shutter speeds because while the shutter speed has no effect on the flash exposure, we have to cease down our aperture to keep the ambient exposure the same at slower speeds, and the smaller apertures used at slower speeds is what demands more flash power.
Changing ISO does nil to assistance since information technology’s the
of ambient to flash light that’s of import. Here’south why:
Exposure equals the expanse under each bend.
The total area for the ambient light increases as you lot consider more than fourth dimension horizontally, due to a longer shutter opening.
The area (exposure) for the flash doesn’t alter and then long as the exposure is at least 1/1,000 2nd to capture it all.
The exposure from ambience light increases as exposure fourth dimension (flash sync speed) gets longer, but the contribution from the flash stays the same. Ane uses smaller apertures with longer exposures, which keeps the ambient exposure abiding but requires more than ability from the wink to keep upwardly.
It is hard for battery powered flashes to compete and balance with direct sunlight equally flash sync speeds become slower. I ofttimes run out of range in daylight with slower syncing cameras, or my flash has to fire at full ability and accept a long time to recycle.
a.) Flash is an instantaneous burst which lasts only nigh one/1,000 of a 2d. You lot go the same contribution to exposure from the flash regardless of shutter speed. Simply the distance, discontinuity and ISO affect information technology.
b.) The contribution to exposure from ambient light varies with shutter speed, but non altitude. Unlike ISOs or apertures don’t alter the ratio between flash and ambience.
c.) Changing aperture or ISO does cipher to bear on the
between flash and ambient calorie-free. The factors which practice modify the ratio are distance, shutter speed or flash power.
d.) If you have the freedom to go to a higher sync (shutter) speed you can utilize a higher ISO or larger aperture to proceed the same ambient exposure while increasing the sensitivity to the flash. Nigh battery powered flashes have to piece of work very hard to compete with straight sunlight unless they are very shut. Faster sync lets you get further away or utilize less flash power. Using less flash power increases bombardment life and reduces recycling fourth dimension which increases frame rate! See likewise Shooting Sequences with Flash.
due east.) Here’s a subtle distinction many people miss: simply using a lower ISO or bigger aperture setting doesn’t assistance unless y’all likewise have access to faster shutter sync speeds to keep the ambience exposure unchanged.
Case 1: Yous can’t reduce the required flash output by increasing the ISO. You will need to use a smaller aperture to go along the ambience exposure constant because you lot can’t increase the shutter speed higher up the sync speed. Because of the smaller aperture at the higher ISO you lot even so need the same flash output. A higher ISO can’t get you lot more range or better bombardment life.
Case two: A lower ISO can let you utilise larger apertures for portraits, just it won’t speed up recycle time (and thus frame rate) or increase range. If you set up a lower ISO and utilize a larger f/cease you lot yet need the same wink power output. A faster sync speed would give you more range or require less power from the flash when using the larger discontinuity.
There are no disadvantages to the availability of faster sync speeds. Faster rated sync speeds merely requite you lot more options. You always can utilize slower speeds with flash.
At low low-cal levels irksome shutter speeds are needed to allow in enough ambient calorie-free. Sync speed is non a limitation. Nosotros don’t need to hold back the ambient low-cal to keep it from overpowering the flash. In dim low-cal we e’er wish we had more ambience light!
To sum up, sync speed is disquisitional for using fill in daylight, and fill is disquisitional to getting expert images in straight sunlight. That’s what makes sync speed critical, in addition to stopping motion.
Sync speed isn’t an consequence in dimmer lite.
Pull a fast one on Modes
Marketing departments like to push the “FP” play tricks flash modes that seem to let you sync at whatever speed, fifty-fifty 1/8,000. This doesn’t count as far as I explicate later here. Canon calls this “High Speed Sync” and I forget what Sigma and others call it. It is not a substitute for genuine fast sync speeds.
Why Yous Intendancedorsum to topskip to summary
Stopping Movementback to summit
At slower sync speeds like 1/180 you’re far more likely to get subject or camera motion and blur than you are at 1/500. You knew this.
Depth of Field Flexibilityback to top
With faster sync speeds y’all can apply larger apertures while retaining the correct ambient lite exposure for fill flash. This is the cardinal to all the other related benefits. Simply setting a slower ISO does cypher to help all the below issues since you have to pump out more flash ability at the slower ISO.
Maximum Wink Rangedorsum to peak
Larger apertures let in more light from the wink which allows you to get further away with any given flash. For a full cease increment in sync speed you get a xl% increase in range since you can open the discontinuity up a end. For a ii stop increase (going from 1/125 to one/500 for example, which lets you open your aperture ii stops) yous double your maximum flash range.
Flash Battery Lifeback to meridian
Larger apertures let in more than light from the flash and thus less power needs to come up from the wink for each shot at a given distance. Less battery power is used to recycle the flash for each shot, since modernistic flashes merely utilise the power needed for each shot and conserve the rest for the side by side shot.
Flash Recycle Fourth dimensionback to top
Since less power is used for each shot it takes less time for the flash to recycle since information technology just needs to supersede the power that was used. If you lot haven’t noticed this, time how long your flash takes to recycle when set to a transmission power setting of i/8 (almost immediate) and so come across how long information technology takes when fix to full (about v to 10 seconds).
Maximum Frame Rateback to top
Yous can’t shoot your side by side shot until the flash is ready. When the flash recycles faster y’all can shoot faster and at a college frame rate. Virtually flashes are however ready to go when used at lower powers at the larger apertures y’all can use with higher sync speeds.
Buffer Depthback to top
Nigh flashes can shoot continuous bursts at lower powers. The lower the power, the more flashes they can burn down off at a time. If more flash ability has to be used for each shot due to smaller apertures caused by slow sync speeds you cannot get every bit many continuous flashes without breaking cadence and having to expect a few seconds for the flash to recuperate. When you lot loose your flash oomph you tin’t go along shooting your sequence.
Allows Use of Smaller Flashesback to top
For every stop of increased sync speed yous just need half the flash ability. Thus a smaller, less expensive wink may be all you need. Even better, the congenital-in flash might be all you demand for fill up!
Faster Sync (one/500)
Slower Sync (one/125)
Depth of Field Flexibility
Fewer large apertures available
Flash Battery Life
Wink Recycle Time
Maximum Frame Rate (FPS)
Allows utilize of smaller flashes
What Limits Sync Speeddorsum to top
Electronic flash is an instantaneous blast of light. At full power your flash may only last for a thousandth of a second. At typical power levels and with automated settings it’due south probably be closer to 1/10,000 of a second.
The mechanical focal-airplane shutter of film 35mm SLR cameras and Leicas are two defunction of metal or cloth that zip across the front of the film. At slow speeds like a full second they zip fast plenty to appear to open and close immediately.
What’southward non obvious to the naked eye at fast shutter speeds is that the second curtain has to commencement zipping across the film correct backside the offset pall. Information technology has to do this considering the curtain speed is not instantaneous. At fast shutter speeds the film is effectively exposed through a slit that zips beyond the film.
If you pop a flash at 1 of these faster speeds and so only the part of the film behind the open part of the slit would be exposed to the wink.
The sync speed is the fastest speed at which the entire pic or CCD can be open to light. This is determined by how fast the shutter curtains move.
At speeds faster than the sync speed the slit that travels across the pic or CCD narrows. If y’all used wink at faster than the sync speed (y’all can’t do this on modern cameras) you would only expose the part of the film behind the slit to the wink.
Nikon has done the world a corking favor in the D1, D1X, D1H and D70 cameras by calculation an electronic shutter to accept intendance of the faster speeds. By doing this the sync speed becomes unlimited. The merely reason the D1, D1X and D1H (and for all I know the D70) limit the speed to 1/500 is because of the loss of efficiency above that speed for shoe mounted flash.
Apprentice digital SLR cameras omit the electronic shutter and are express by the mechanical focal plane shutter.
Betoken-and-shoot digital cameras usually sync at high speeds like 1/500 because they too have electronic shutters.
Leaf shutters as used in professional person cameras like the Hasselblad and large format cameras tin can sync at any speed. This is because their leaves open completely at all speeds, at which bespeak the flash is fired. There is no slit or partial opening at the fastest speeds.
(as well called High Speed/FP flash sync on Canon) dorsum to height
Now that y’all know that the shutter needs to get all the style open to allow the instantaneous pop of an electronic flash expose all of the film or sensor, what if instead we fabricated the flash stay on long plenty to let the curtains of a focal aeroplane (FP) shutter complete their travel from one side to the other? Nosotros could allow the flash betrayal the moving-picture show or CCD at any shutter setting during the time it takes the curtains to travel from ane side to the other.
You can do that equally a play a trick on mode with many loftier-terminate flashes and cameras. Information technology’s called the FP mode.
There are many disadvantages, which is why I don’t e’er use these modes.
ane.) FP mode often reverts to totally manual exposure calculation. If so, it’s simply useful for shooting things that stay at the same distance so yous tin can summate it. I saw this feature illustrated in a Nikon brochure, and lo and behold, the two examples were i.) a water skier shot from the boat (the rope stays the same length) and ii.) a shot of a race motorcar made from a photographic camera bolted to the auto and fired remotely. Some newer cameras like the D2H have automated this, finally.
2.) The wink always pops at full power on the flashes I’ve seen. Thus as above you lose battery life, have long recycle times, no high frame rates and all the other disadvantages above.
3.) Since merely a fraction of the light at whatever time is exposing the film or CCD you lose a lot of calorie-free, again getting y’all dorsum to the bug of limited flash range. The loss of light also depends on the shutter speed you apply, thus the flash guide number used in manual calculations in one.) above changes with shutter speed! You lose almost of the low-cal at the faster speeds and lose less at slower speeds.
At to the lowest degree FP manner gives yous the flexibility to employ whatever shutter speed and also considering you lose a lot of calorie-free yous can go to the larger apertures.
This can be a handy feature in limited applications, all the same in that location are so many limitations you run across why I don’t consider it anywhere every bit useful as a healthy true sync speed.
Some of the very latest cameras like the Nikon digital SLRs and Minolta Maxxum/Dynax 7 have FP modes that are TTL and do vary the power down from full. This mode you accept but the disadvantage of 3.) above. I have not researched these; believe it or not I’m besides lazy.
Survey of Sync Speeds
back to top
1/2,000 and in a higher place: Nikon D1, D1X and D1H cameras when used with an external PC cord. The Nikon D70 when non used with a dedicated flash, for instance, an old 1980s not-defended wink or probably besides when used with the shoe-mount sync adapter for external flash. Y’all tin fool the D70 by undedicating the flash past roofing all just the large primal hot shoe contact.
These camera’south electronic shutters are efficient enough to sync clear up to the full 1/xvi,000 or 1/eight,000 speed, although of course with most strobes you’ll lose a lot of light. You lot won’t get a partially black frame as you volition when using the wrong sync speed with a conventional focal aeroplane shutter camera.
Rollei PQS series foliage shutter lenses.
one/500: Almost professional DSLR and film leaf shutter cameras including Hasselblad, 4×5″ view camera lenses, the Plaubel 67, and the Nikon D1, D1H, D1x and D70 when used with shoe-mounted flash. Also most point-and-shoot digitals, since they often incorporate electronic shutters.
1/250: most good 35mm film SLRs from the 1990s through today. The Nikon D2H and D200 and Canon 20D and fancied DSLRs
1/125 – 1/250: Amateur SLRs from the 1990s and amateur DSLRs like the Canon 10D, Digital Rebel, Nikon D100 and the Sigmas etc.
1/60: Amateur SLRs from the 1970 and 1980s, like the Olympus OM-ane, Minolta SRT series and X-700.
one/fifty: Leica rangefinder cameras, even today (pretty poor!)
1/30: focal plane shutter SLRs before the 1970s, X-sync foliage shutters used with M type flashbulbs, Russian medium format SLRs similar the Kneb/Kiev.
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Flashbulbs apply magnesium foil that burns when triggered by an internal electrically fired squib. They usually burn for about 1/30 of a 2d and take a trivial while to reach full brightness. Thus shutters intended for flashbulbs have a position marked “M” which triggers the flash an instant before the shutter really opens.
You can utilise all speeds on a leaf shutter with flashbulbs and M sync, although of course at the faster speeds you’ll not capture all the light of the flashbulb. The guide number tables that come up with your flashbulbs reflect this past having unlike values for dissimilar shutter speeds. Flashbulbs, dissimilar electronic flash, are non very good for stopping action. That’south why Nikon named their electronic flashes “speedlights” when they came out in the 1960s.
For focal plane shutters you need special “FP” (Focal Aeroplane) flashbulbs if you lot want to use them at shutter speeds faster than 1/30. Only similar the screwy FP modes of some fancy electronic flashes, utilize at college speeds wastes a lot of calorie-free but it works. FP flashbulbs attempt to accept a constant light output across well-nigh 1/xxx of a second so every bit the focal plane’s slit moves beyond the film yous get even exposure. Regular flashbulbs accept a peak of light and are best used with leaf shutters if you need to shoot at faster than 1/thirty.
Older cameras and shutters intended for use with both electronic flash and flashbulbs take either a 2 position switch or ii separate sync terminals. “M” is for flashbulbs and “X” is for electronic wink. “M” fires the wink an instant before the shutter opens to allow the flashbulb to be at the best brightness. “10” sync triggers the wink the instant the shutter is completely open, since electronic flash fires instantly.
Yous can apply most flashbulbs on modern cameras at 1/30 at either sync setting.
If you use an electronic flash at the M setting y’all’ll see no flash on the film, since the flash would have been triggered an instant before the shutter opened. This used to mess a lot of people upwards in the 1970s since the flash would go off, but not testify up on film!
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As you’ve read higher up, “Yard” sync on older shutters fires the flash before the shutter opens, commonly ruining your photograph with electronic flash.
On the other hand,what if y’all photographed something that glows in the night? Aye, the wink will pump it and your exposure will exist made at the maximum glowing with no contribution from the flash. This is a cool trick for photographing phosphorescence.
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