Paul C. Buff, Inc. Technical Forum

Hello,
I just purchased a pair of WL Ultra 1800’s. With unit turned on, set at full power, and the green light lit the unit will flash when the test button is pressed. I was trying the built in slave tripper today and have encountered issues.
My camera is a Nikon 7000. Iso 200 5.6f @ 1/250.
At lunch time I was in my kitchen with the WL 1800 sitting on the bar pointing at the living room wall about 15ft. away.
I was standing behind the WL 1800 and trying to use my on camera flash to trip the unit.
I can see the WL 1800 flashing but my photos are dark.
With everything set the way it is and in the small are that I was shooting the WL 1800 should have totally blown out the photo (all white). Is there an issue with my sync speed? It seems that the shutter is doing its thing before the WL 1800 is firing. Is there lag time between the on camera flash firing the WL 1800 firing?
I have to be able to shot at least 1/250 because I bought these WL 1800 to use in poorly lit rodeo arenas.
Will radio triggers sync the flash speed better to the shutter?
Thank you,
Fred

What is actually happening is the flash is firing before the shutter "does it's thing". All digital cameras differ from typical film cameras in that they fire two flashes. The first is a known output and is used to judge how much light should be applied for proper exposure during the second burst, when the sensor is exposed. This pre-flash, as it is known, is enough to trigger the monolight. But since it comes before the exposure, it does not contribute to the exposure (and will render an underexposed image).

Fortunately, the camera you are using will allow you set the flash to manual, which results in a single burst timed correctly. You can also dial the power of the pop up down so that it does not significantly contribute to the exposure. On Nikon cameras, it is generally in the pencil menu, under the heading of "built in commander" or something similar to that. Your camera manual will provide specifics.

I will have time this evening to experiment more.
Thank you for the information.

Works like a charm now.
Thank you

no problem, glad it is working for you now!