Flash synchronization in 1/8000 with Nikon D70

I have a D70 and I am using my old Metz BCT4 flash. I wanted to

see that the photograph must be cut in shutter speeds faster

than 500 but it didnot. Then I made an experiment. With 50 mm

1:1.2 lens I set the aperture to 1.2. I set the flash power to M that

means it will deliver the maximum light. And took my son's

picture from 2 meters distance. The result was a white screen. I

started to increase the speed to 640 and so. First pictures

started to come speeds around 4000 and I have clear

photographs at shutter speed of 8000!!!. I told this to one of my

professional photographer friend who suses a Nikon D1. He told

me that this is against the nature of the camera. Yes it is I also

know that but he saw it and performed the same experiment with

his D1 using my flash and he could go up to shutter speed of

16000. This is the experience that we could not find an answer. I

am planning new experiments to prove the syncronization

speed. Does anybody have an answer to it or knows something

about the situation.

I would set things up so that the flash was providing the primary source of light for a picture, set the flash level so that the exposure was correct using a shutter speed that the camera is supposed to sync to (=> 1/500) and then keep increasing the shutter speed and see what happens to the exposure. A white screen isn't a usefull picture. If you can't take real flash pictures above 1/500 sec, who cares if you get a white screen.

I think you can rest assured that if the actual sync speed was 32 times faster than what it is advertised, that Nikon would be aware of it and would be advertising it with that in mind.

 

There are two possibilities:

1) You don't understand the inner workings of the flash exposure system and it is actually setting a slower shutter speed than what you are choosing. (I'm not familiar with those cameras, so I can't comment on that)...or:

 

2) The actual duration of the flash is longer than 1/500, so the flash is lit up during the whole time the slit in the shutter is passing over the sensor. I understand that typical flash duration is around 1/1000, so this could be the case. However, in this case, faster shutter speeds will give less and less light from the flash on the sensor. Try taking photos in a reasonably dark room at a fixed aperture, fixed flash setting, and see if they get darker and darker as the shutter speed increases. Normally, this won't be the case, and if a camera syncs at 1/125, then setting it to 1/30 won't let any more light from the flash in than 1/125. This effect would be similar to the high-speed sync used on some other cameras.

The D70 has a hybrid mechanical/electronic shutter. The mechanical part never goes faster than 1/125th second - above that the electronic shutter takes over (you can easily hear that this is the case from the sound it makes). This, of course, is the reason that it can handle the unusually fast synch speed of 1/500 in the first place.

 

I have a D70 and can confirm Kamil's findings. I suspect the reason Nikon don't advertise the synch speed as 1/8000 is that it doesn't work in all cases with all flashes (the Nikon flashes prohibit you from setting a shutter speed above 1/500) or that they didn't see why anyone could possibly want such a fast synch speed!

There's an older thread on this:

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00A0kp

A Vivitar 285 will indeed sync up to 1/8000 with a D70. The sb800 normally won't, because the camera "knows" there's a flash attached, and won't let you set the shutter above 1/500. But you can fool the camera with a Wein Safe-Sync since it just has the central contact and the dedicated pins aren't connected to anything. Keep in mind though that the maximum flash duration is typically 1/1000 sec. So if you have set the shutter to 1/8000, there's no point to full power on the flash. Very roughly speaking, every time you cut the power in half you cut the flash duration in half. But I don't think that's strictly true for all flash units at all times; some experimentation is in order.

<I>I have a D70 and can confirm Kamil's findings. I suspect the reason Nikon don't advertise the synch speed as 1/8000 is that it doesn't work in all cases with all flashes (the Nikon flashes prohibit you from setting a shutter speed above 1/500) or that they didn't see why anyone could possibly want such a fast synch speed!</I>

<P>

I can think of an application right away: duplicating the look of 1940s-style synchro-sunlight pictures taken with a 4x5 Speed Graphic and flashgun.

<P>

By shooting at 1/8000 outdoors with a powerful flash, you could dramatically illuminate the subject while plunging the background into darkness, even in broad daylight. Think Weegee!

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00AXnh

Except that even the most powerful electronic flash limited to a duration of 1/8000 sec isn't going to have anywhere near the light output of one of Weegee's bulbs.

Hello it is Kamil Again

 

I have started to make experiments on my D70 and Metz 30 BCT4. I tried to take frozen photographs of the propeller of my radio control plane. It freezes it with 1/8000 bu thave ghost image with 1/500 on 15000 rpm.

I performed the experiment of sync speed with a Cannon EOS 1 Mark2. With its dedicated flash you can set shutter and aperture to any measures you want with the flash but it changes the speed to 250 as you fire. It doesn't let you a faster speed then its sync speed. But we could cheat the EOS with my Metz so it did not see the flash. This time it fires as you choose and mambo! it cut the film and we could not be successful to go faster than 250. I used Cannon's dedicated flash on my D70. As the camera did not see it it worked as undedicated flash unit and shot in its full power. It worked as same as my Metz. We used the same flash on D1 it synched up to 16000. I am a neurosurgeon and I know what ?statistically significant? is. They are very few experiments but I believe that the setup is correct. It is tested in 3 cameras (2 Nikon 1 Cannon) with two flash units. It is worhing with Nikon D70 and D1 and they syncronize up to 8000 and 16000 respectively. Actually I don't know what to do with those speeds if you can't syncronize the speed with the event that may need dedicated equipment. If anybody wants the original photos I may e mail them.

Thanks Frank

 

I have my answer.

 

Best regards

Kamil Oge MD PhD

<I>Except that even the most powerful electronic flash limited to a duration of 1/8000 sec isn't going to have anywhere near the light output of one of Weegee's bulbs.</I>

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That's true. But I tested my Sunpak 383 with a Nikon D70 at high shutter speeds and it works. At 1/8000 sec, I got proper sync, though the picture is 1-2 stops underexposed. At 1/4000 sec the exposures are OK. Using ISO 200 and the Sunpak at close range, I can properly expose a subject while underexposing even a bright sunlit background by a few stops. The background isn't jet black, but it's dim.