Sych Speeds faster than 1/500 of a second with D70

Started Apr 2, 2004 | Discussions thread
SteveL54 Senior Member • Posts: 2,709
Re: Sych Speeds faster than 1/500 of a second with D70

You won't need any tape modification for the D200 to do FP sync. The D200 comes directly with the support for FP sync.

FP sync is a special way of driving the flash unit so that it can be used at shutter speeds higher than the normal sync speed. This is done to deal with fact that the shutter curtain for speeds greater than 1/250s on the D200 (mechanical shutter) forms a narrow slit as it crosses the sensor. So the entire frame would not be illuminated by a standard single burst of flash. So a series of very rapid but small bursts are output.

However FP sync comes at the cost of greatly reduced flash output. I understand the output is at least an eighth that of normal flash. So it can't be used to illuminate things nearly as far away. That represents 3 full stops. Look at table on page 31 of SB-800 manual. At normal sync, ISO 100, f/2.8 and 35mm zoom head position the max range is 44 ft. At FP sync you are down to at least 16 ft and maybe less. I think the effective output is reduced even further as shutter speed goes up.

The D70 has an electronic shutter combined with a mechanical shutter which allows it to sync to a flash at higher speeds than those bodies that contain only mechanical shutters like the D200 and D80. This is where the tape trick comes in on the D70. It can actually sync at much higher speeds than 1/500s as the OP has demonstrated. Although I'm sure there are potential flash loss effects at speeds above 1/1000s for the SB-800. That happens to be its flash duration at full output. (see page 122 of SB-800 manual). At 1/128 power the flash duration is only 1/41600s.

If the tape trick were to allow one to set the shutter speed above 1/250s on the D200, operating the flash would result in a partially exposed frame unlike on the D70.

BTW: The OP could have gotten the same shot by just using the flash at 1/128 output and a normal sync speed as long as there is little or no ambient light contibuting to the exposure. At 1/41600s the flash freezes the water.

The D200 Users Manual may have some detailed info on FP operation. You should be able to download the manual from NikonUSA web site to do futher research.

What exactly do you intend to use the camera for that requires these special shutter and flash speed combinations?

Steve

lexygirl wrote:

Looking strongly at purchasing a D200 but wasn't making any quick
moves to do so before a great deal of research. I really need this
feature and wasn't pruchasing anything until I found a compatible
camera in my price range.

Do you know if this feature is completely accessable WITHOUT the
tape modification...for sure?????

lexygirl

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