Please help me understand flash sync speed.

[JustJazzie]

Nikon lists my flash sync speed as
"Flash sync speed
X=1/200 s; synchronizes with shutter at 1/250 s or slower" I've read the manual, but I still just don't quite get it.

if I shoot anything above 1/160, I am experiencing the black banding in the lower frame. (I've tried with both my flashpoint strobes and my yognuo speed light. I do not have a nikon flash)

So, what am I doing wrong here? Or do I need a compatible flash to make this work?

 

[tirediron]

I assume it's a flash issue; what sort of triggers are you using with your Flashpoints? I have no problem triggering my Speedotron lights with a PW. I would think the YN would have no problems, but it's not unheard of.

 

[Forkie]

Do you still have the instructions or access to the specifications for your flashgun? It could be that the flash duration on your flashgun could be slower than (or equal to) 1/160. It would be unusual, I think, but possible. That would also cause the banding at the bottom of the frame.

 

[JustJazzie]

I am using photix ares triggers with the flashpoint and the speed light. I've also tried the speed light in the hotshoe. The speed light manual says flash duration is 1/200-1/20000

Amazon.com : Phottix Ares Set Wireless Trigger (Black) : Photographic Lighting Slave Remote Triggers : Camera & Photo

 

[JustJazzie]

Hmmmmm.... maybe what I am seeing is actually just strong fall off from the flash?? It's not completely black just nearly....

 

[tirediron]

Post a picture.

 

[Braineack]

I can only sync up to 1/160 with my YN603 triggers even though I have a flash sync of 1/200.

Put the flash directly on the camera and it's back up to 1/200.

 

[TCampbell]

The flash sync speed assumes the flash will fire when the camera sends the trigger voltage is sent to the hot-shoe.

If you mount a wireless trigger on the hot-shoe and it has to react to the trigger voltage then send a signal to a remote system... which then has to detect that signal and fire it's local flash, you'll incur a slight delay/penalty. It's not much... but often enough that you can no longer run at max flash-sync spneed to dial back the shutter speed by a notch to avoid the banding.

Your camera is probably working just fine... it's "everything else" which is delaying the flash just barely enough to cause the banding.

 

[gsgary]

Why are you using 1/160 ? The flash freezes the action unless there is ambient light

 

[xzyragon]

You might get better results if you put your flash in HSS. But if there's enough ambient light to warrant using a flash at over the sync speed, it's time to reposition your model, or use reflectors.

 

[Braineack]

she might get better results if she uses a 2sec exposure and the flash at 1/128 power.

 

[JustJazzie]

Thanks all! You've been super helpful. I won't bother posting a picture as I think I have enough info to trouble shoot. Fyi- this isn't an actual "issue" as I've never needed to shoot above 1/160 just trying to understand a little better.

 

[KmH]

Is your camera set up to sync the flash on the front/first curtain or the rear/second curtain?

Take note - the image the lens projects onto the image sensor is upside down.
So the top of the image is at the bottom of the image sensor. Unless you are shooting in portrait mode. In portrait mode the black band would be on the right or the left of the image.

So a dark band at the bottom of the image frame would indicate the flash may be firing after the rear/second curtain has started closing to end the exposure.
But at the x-sync speed of your camera 1/200 the rear/second curtain should not be closing at shutter speeds of 1/160 to 1/199.
At any shutter speed below 1/200 both shutter curtains are fully open during an exposure.

So. it sounds like your triggers are the issue. It's likely that 1/160 is the max shutter speed they can perform at.

 

[JustJazzie]

Is your camera set up to sync the flash on the front/first curtain or the rear/second curtain?

Take note - the image the lens projects onto the image sensor is upside down.
So the top of the image is at the bottom of the image sensor. Unless you are shooting in portrait mode. In portrait mode the black band would be on the right or the left of the image.

So a dark band at the bottom of the image frame would indicate the flash may be firing after the rear/second curtain has started closing to end the exposure.
But at the x-sync speed of your camera 1/200 the rear/second curtain should not be closing at shutter speeds of 1/160 to 1/199.
At any shutter speed below 1/200 both shutter curtains are fully open during an exposure.

So. it sounds like your triggers are the issue. It's likely that 1/160 is the max shutter speed they can perform at.

I do think I have rear curtain sync on now that you mention it! I was testing it out with the boys on their dirt bikes trying to pan and then flash. Perhaps this is my issue!

 

[qleak]

Thanks all! You've been super helpful. I won't bother posting a picture as I think I have enough info to trouble shoot. Fyi- this isn't an actual "issue" as I've never needed to shoot above 1/160 just trying to understand a little better.

(Please excuse my inner mathematician he really likes to compute log base 2 of quotients)
1/160th is only 0.64 EV brighter than 1/250th. So approximately +2/3 EV that's not a huge advantage

I do think I have rear curtain sync on now that you mention it! I was testing it out with the boys on their dirt bikes trying to pan and then flash. Perhaps this is my issue!

This is still a hardware compatibility issue, but presumably not a big deal when you actually want rear curtain sync right? You'd be dragging the shutter anyway