Fast Sync

[frankie_frank1]

What is that? What is the benefit?

[mark_sirota1]

Search for "high speed sync" or "FP sync".

[hans_janssen]

You can use big aperture in bright conditions, so a fast shutter speed, and still use your flash. Normally the min sync speed is 1/250 or 1/500.

[fk319]

Fast Sync is when your flash is much longer than your shutter speed.

This has the neat effect being able to take a picture of city lights, need a slow shutter speed, and a person in the foreground.

The flash is at the beginning of the shutter cycle, there is also rear sync when the flash is at the end of the the shutter cycle.

for stationary objects, it does not make a difference, but for taking a picture of a car at night with the tail lights it does.

Taking a Fast Sync of a car would flash the car, and the rest of the shutter would get the streaking lights. The effect would appear that the car is going backwards. In this case you want to catch the lights streaking then get the cars position at the end lights.

Basicly you use this feature when you are taking a picture of two sceems in one, one is dimly light and far away, ie needs a long shutter speed, and one that is closer and can be illuminated with a flash.

[lex_jenkins]

The FP setting, at least on my D2H with the SB-800, automagically modifies how the flash works to accomodate shutter speeds faster than the true 1/250 sec. sync speed for a typical focal plane shutter.

 

With most non-dedicated flash units, when the shutter is set faster than its real sync speed, part of the frame will be darkened due to vignetting caused by the shutter curtains.

 

The SB-800 output is modified to evenly illuminate the entire frame. Some folks criticize this "feature" because the flash duration must be slower to accomplish this trick. To me, it's a non-issue. If I need a shutter speed faster than 1/250 with flash, it's because I'm using fill flash in daylight. The shutter speed freezes the action, not the flash.

 

And if I need to freeze action using flash, it's because the surroundings are dark. So it doesn't really matter that the shutter speed is "only" 1/250 or slower.

 

However, some Nikons with "hybrid" shutters (I'm not sure whether that's what Nikon officially calls 'em) can naturally sync beyond 1/250. I think these include the D70 and D1-series (D1, D1H, D1X). It works pretty much the same way most CCD P&S digicams do. There's either no mechanical shutter, or a mechanical shutter that comes into play only at certain shutter speeds. My "ancient" Olympus C-3040Z P&S digicam will sync at all shutter speeds, up to the max of 1/800 sec., so it'll perform tricks like freezing spinning fan blades if for some silly reason I want to do that instead of just turning off the fan and then photographing it.

[cenelsonfoto]

I've no idea how to accomplish this with other Nikons, but my D70s will hit full 1/8000th sync via the following:

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1) I connect an SC17 to the hotshoe of the camera<br>

2) I plug an SC19 into the connection on the SC17 shoe<br>

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Using step one, I can only attain 1/500th max sync. Via the combination of the SC17/SC19, I can reach max-shutter sync.

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I do believe this can also be accomplished by masking off one of the contacts on the camera hotshoe, as illustrated here:

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<img src="http://www.photo.net/bboard-uploads/00CbX2-24229784.JPG">

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In fact, I'll try that on my morning shoot. One less cord to worry about, though the added reach comes in handy when shooting the speedlights into umbrellas on stands.

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C.