high speed sync question: QuantumT2 with Canon 5D

[jay_kim6]

580EX and 5D can do a high speed sync. It goes over 1/250 of a second shutter

speed. But at the lowest ISO I shot and f stop 2.8 but it didn't work, it was

overexposed.

 

Any suggestions other than using an ND filter? I need 2.8 aperture.

 

I would really appreciate any advice.

 

Thanks very much.

 

Jay K

[Ed_Ingold]

Are you asking about a Quantum T2 or a Canon 580ex?

 

The exposure will depend on the power setting of the Quantum T2 and the distance to the subject, as well as the aperture and ISO setting. The shutter speed has no effect on flash exposure as long as it is below the maximum sync speed (e.g., 1/250) for the focal plane shutter. You will still get an overexposure situation if the ambient light is too strong at f/2.8 and 1/250 second.

 

Do you have the correct TTL Module for the Quantum? If not (or if it doesn't seem to work), place the Qflash in Auto mode, set the ISO and aperture to that of the camera (e.g., ISO 100 and f/2.8). If the flash is too powerful even yet, you will get a warning signal from the T2 (the ready light will flash). You can also set the Qflash in manual mode, and reduce the power to as little as 1/64 full power (-8 stops).

[jay_kim6]

Thank you so much for your help

 

Yes I am talking about Quantum T3DR I just updated to Digital unit from T2

I can sinc high speed with 580EX(goes over 1/250 of a second shutter speed)

But I can't do it with Quantum T3DR at QTTL mode.

I didn't try with manual mode or auto mode but I just worried that I am gona get half black( over 1/25o, First & second cutun problem )

[bruce_rubenstein]

The Quantum will not do HS sync (multiple flashes at shutter speeds above 1/250 sec.) in any mode.

[jay_kim6]

Mr Bruce

How are you shooting using the Quantum outdoors on a sunny day?

[conraderb]

jay - the T2 can't sync higher than 1/250th with your camera. the camera is actually the limitation, I think.

[bruce_rubenstein]

I don't use the Quantums for on camera flash; only lightstands. On a bright sunny day I would only use flash for fill anyway and the Nikon flash works for that.