On Camera Fill Flash Above Max Sync Speed

[billross77]

Ok I came across this yesterday. If I am shooting outside in good light at say f2.5 on a portrait but I have some shadows that I want to fill. First though in my head is to throw on my 430ex II and use either manual or eTTL with FEC turned all the way down. Now Ill throw in that using f2.5 on Av mode, my shutter speed is 1/1000. My 430exII has a max sync speed of 1/200. Is it best to shrink the aperture to lower the shutter speed but give up the shallow depth of field or is there a way to do this in LR to cover the shadows?

 

[analog.universe]

You'll actually want to be using a neutral density filter for this. If you want shallow DOF and you want to shoot at f/2.5 to get it, and the ambient light is coming in at 1/1000, the solution is to decrease the intensity of the ambient light. With a 3-stop ND you'll get that same shot at 1/125. Your flash will need to fire 3 stops hotter to make it through the filter, but that shouldn't be a problem considering you've got it turned down anyway.

 

[Opher]

you can also set your flash to "high speed sync" read your flash manual and it will give you more info. but it can only be used like this on camera or with a ttl cord. adide from that you can use a ND as analog said

 

[billross77]

Ive never used an ND filter. I'll have to check it out.

 

[MReid]

high speed sync, or change your location or time of day

 

[jwbryson1]

Will high sync speed yield enough power to give him sufficient fill light?

 

[MReid]

Yes I use it all the time.

 

[Trever1t]

Yes it will. I took my last set with camera set manually and fill flash at -1 stop TTL. Shutter speeds well over 1/800+

 

[Big Mike]

My 430exII has a max sync speed of 1/200.

That is actually a limitation of the camera, not the flash. The camera's shutter works at two curtains. Both starting from the same side, the first one opens to start the exposure and the second one follows it to end the exposure. At speeds over 1/200 (on your camera) the second curtain starts moving before the 1st curtain is all the way open. So at speeds higher than the maximum sync speed, the sensor is never fully open, so the burst of light from the flash (to the subject and back) could not illuminate the whole scene.

As mentioned, you can use the HHS mode on your flash. This causes the flash to use multiple pulses of flash, rather than one burst...so you can use flash at any shutter speed on your camera.
The down side is that it greatly reduces the output (working distance). So you could try it, but be aware that it may not work if your subject is too far away.

 

[billross77]

I'll give it a shot. I did look in my bad and find that I had a 58mm nd4 filter still in its packaging. The day is looking up.

 

[KmH]

Here is an excellent video that explains Shutter/Flash Synchronization very well.

 

[Tiberius47]

With HSS you lose about a stop of flash power, but it's by far the easiest option for what you want to do.

 

[Dominantly]

Will high sync speed yield enough power to give him sufficient fill light?

Not always. High Sync Speed is a power killer for your flash.

 

[Derrel]

Will high sync speed yield enough power to give him sufficient fill light?

As you can see by the replies of MReid and Trever1t, HSS works because outdoor flash FILL-IN lighting needs to be somewhere around 2.5 to 3 f/stops LESS than the ambient light level, so...full power flash is the exact OPPOSITE of what is desired....one actually wants the flash to be well,well,well "under" the ambient light exposure, so the flash acts merely as shadow-FILL, and not as the primary/main/key light source. And, at wide apertures, even a teensy little bit of low-powered flash is easily bright enough to register as being "three stops under" the main light's intensity level.

I just want to point out that my comment is directed at using HSS flash as FILL-IN lighting, and NOT as the "main" lighting source...trying to use HSS as the MAIN source of light at longer distances can be problematic, or even a total failure. Success or failure "depends" on several factors.

 

[Tiberius47]

Will high sync speed yield enough power to give him sufficient fill light?

As you can see by the replies of MReid and Trever1t, HSS works because outdoor flash FILL-IN lighting needs to be somewhere around 2.5 to 3 f/stops LESS than the ambient light level, so...full power flash is the exact OPPOSITE of what is desired....one actually wants the flash to be well,well,well "under" the ambient light exposure, so the flash acts merely as shadow-FILL, and not as the primary/main/key light source. And, at wide apertures, even a teensy little bit of low-powered flash is easily bright enough to register as being "three stops under" the main light's intensity level.

I just want to point out that my comment is directed at using HSS flash as FILL-IN lighting, and NOT as the "main" lighting source...trying to use HSS as the MAIN source of light at longer distances can be problematic, or even a total failure. Success or failure "depends" on several factors.

This. The only time when you are likely to have trouble with HSS outdoors is if the flash is far away, or if you are trying to overpower the sun. Fur use a fill light just a few feet away, the reduction in power caused by HSS is unlikely to cause any significant problems.