Flash sync setting.

[Gigas]

Sometimes the normal setting for flash/strobes 250/sec gives me a black band at the bottom of the image. The 250/sec is the proper setting so wye is this happening? There is also a flash setting beside the "bulb" setting at 320/sec. but no luck there either!

[Ilkka Nissilä]

Sometimes the normal setting for flash/strobes 250/sec gives me a black band at the bottom of the image. The 250/sec is the proper setting so wye is this happening? There is also a flash setting beside the "bulb" setting at 320/sec. but no luck there either!

Are you using a Nikon flash? Which camera and flash model?

When using third party radio triggers, it can be a good idea to use 1/200s instead of the 1/250s as there can be a slight additional delay due to the trigger used. I notice this with Elinchrom Skyports in the normal triggering mode 1/250s causes a faint band which is absent at 1/200s. They also have a faster triggering mode which should make this issue go away but it may reduce the range.

[Bjørn Rørslett]

What camera? Not all Nikons support 1/250 sec as synch speed. Thus, the recommendation of using a slightly slower than the nominal synch speed, say 1/200 sec, is a good starting point to avoid further issues.

Like Ilkka, I have noted the occasional tendency to partial underexpose when a DSLR is combined with studio flashes and remote triggering (Pocket Wizard) is used.

[charlie]

The 1/320s sync speed is for use with Nikon speed lights, which shouldn't have a problem when used at 1/250s or 1/320s.

I can vouch that both Nikon and Canon cameras, when used in conjunction with pocket wizards & Profoto strobes (acute series at least), will need the shutter speed to be set a third of a stop slower than the rated sync speed to avoid this issue. I've not tested if it is a delayed trigger sync or slow flash duration that causes the issue, though if you use strobes with faster flash duration the issue does not seem to present itself. I suppose a test would be as simple as connecting directly to the pack instead of using radio triggers. Perhaps I will test this and report back.

Also when using the strobes mixed with ambient light often the ambient light will mask the light fall off and won't be noticeable.

[John Geerts]

I have the same experience as  Ilkka and Bjørn and need to use 1/200s when using radio triggers off camera flash.

[the solitaire]

And another vote of confidence, using Yongnuo triggers, I also need to use 1/200th or slower, where the Nikon SU-800 with SB-600 and SB-700 flashes worked fine at 1/250th with D300, D800 and D3.

[armando_m]

Depending on the studio/radios, I have used down to 1/160

but with nikon flashes there is no problem when on camera or using CLS

[David H. Hartman]

If the flash duration is too long there may be some shading at the top of the image at 1/320 and 1/250. This is shading not a black bar. This can occur when the power setting on an SB-800 or SB-700 is set to full or half power. One is most likely to see this if there is a white background. The cure is to use 1/200 if using full power or full power. I think I saw this with my Norman P2000X studio unit also. The reason this occurs is the t0.1 flash duration is longer than the shutter curtains remain fully open so part of the tail is clipped on a part of the image. This does not occur with the SB-800 and SB-700 at 1/4 power or lower due to the way the flash duration is truncated by the IGBT circuit. This is seen with other Nikon and Canon flash not just the units tested.

I use Phottix Strato II radio triggers and I'll lower the flash sync speed 1/3 stop slower shutter speed to accommodate the added latency.

Dave Hartman

Please note that Canon calls their flash "Speedlites" because they are less filling.

[Gigas]

250/sec with remote trigger do not work but with cable it is ok! As I have to crop quite a bit I can use 320/sec. with a smaller dark area at the bottom on my D810.

[Erik Lund]

Some Elinchrom Flash heads, strobes, can do 1/8000 with the remote trigger: Skyport PLUS HS, I use it at it works very nicely!