Flash sync speed?

[Jarrell]

The answer to this is probably in my instruction book.... if I could find it.. so maybe you know the answer.
With my D100 and sb-80 flash, why does the camera seem to default
to 1/60th second shutter speed when using the flash unit (d-ttl mode) instead of its highest sync speed of 1/160th? It does this in A and Program mode and will only use the higher speed if that is what is chosen in S mode.
Jarrell

 

[Baywing]

Is there enough light? In bright conditions, my D100/SB 80 combo shows the correct shutter speed, and goes "HI" if the shutter speed goes over the 1/160. I dial in more f stop to bring it down. I always shoot in A, so I can't say about P. As for slower shutter speeds, I select rear/slow sync on the camera and the flash relies on the selected fstop/shutter speed. I run the flash in the TTL mode, turn off the flashing matrix symbol.

 

[gho]

instead of its highest sync speed of 1/160th?

The D100's sync speed is 1/180.

I think in P mode, the camera will try getting 1/60.

 

[Jarrell]

Is there enough light? In bright conditions, my D100/SB 80 combo shows the correct shutter speed, and goes "HI" if the shutter speed goes over the 1/160. I dial in more f stop to bring it down. I always shoot in A, so I can't say about P. As for slower shutter speeds, I select rear/slow sync on the camera and the flash relies on the selected fstop/shutter speed. I run the flash in the TTL mode, turn off the flashing matrix symbol.

Hi Baywing,
Actually I had noticed this before but just never followed up on it. Last night right at sunset I was trying some 'action' shots of Hannah chasing a ball and I was using the flash, in A mode. The shutter speed didn't vary from 1/60th sec. I had always assumed the camera would select the highest possible sync speed when using a flash unit. Evidently I assumed wrong.
Jarrell

 

[Jarrell]

instead of its highest sync speed of 1/160th?

The D100's sync speed is 1/180.

I think in P mode, the camera will try getting 1/60.

Thanks for that correction Gregory. I just wonder why the camera would default to a lower speed instead of the highest it's capable of. It's true that the actual exposure is made at the duration of the flash, but when in P mode in conditions that have some 'fairly' bright ambient light I would have thought it would opt for the higher speed.
Maybe I just didn't read the instruction manual well enough and it must say (if I can find mine) that if you want the highest sync speed you'll have to use S mode and set it there and leave it.
Jarrell

 

[Baywing]

Jarrell,
Most of the Nikon bodies I have had default to 1/60 for flash when the ambient light isn't enough. I would guess that 1/60 was the norm for many years (for many years, it was THE sync speed, maybe had to do with flashbulbs...) and it also allows for as much ambient light for background as possible. In the conditions you describe, if you had dialed in slow sync on the camera, I think you would have found a base exposure slower than 1/60. The solution, ultimately, is to do what you suggest and set the camera to S priority and dial in what you want.

 

[David H. Lewis]

I had the same question about my D70. Yes, you'll collect more ambient light at 1/60th, but the chance of losing some sharpness to camera shake is much greater at 1/60th than, say 1/250th.

 

[Baywing]

True, David, but I think this all goes back to the days of flash bulbs, where there was a distinct "delay" in firing. It took the bulb a little longer to get burning than the capacitor discharge of today. I would bet the D70 works the same way, it seems to be a tradition.....