A bit faster

[markyboy.1967]

my wife wants me to do some fun images of the dogs after seeing dogs catching treats on FB. I have only ever used shutter speeds up to 1/200th with the studio lights which wont be fast enough. I have access to different lighting at work but do i need to buy something like the superfasts or is there a way to catch them without blurring. I would use a white black or grey background. What settings are required for this type of fun shot in camera?

 

[Phil V]

Try it with what you have, remember regular studio heads are at their fastest at high power, and that the effective 'shutter speed' is actually the flash duration.

 

[markyboy.1967]

Thanks Phil, i would think i would require around 1/800th or faster. My heads are just the 2x Lencarta 200w and a 300w so not sure if they will be up to the job. The guys at work us video equipment including lighting for another option. Camera will be my D4s so it will be fine. Any idea of settings to try to catch some action?

 

[Phil V]

Thanks Phil, i would think i would require around 1/800th or faster. My heads are just the 2x Lencarta 200w and a 300w so not sure if they will be up to the job. The guys at work us video equipment including lighting for another option. Camera will be my D4s so it will be fine. Any idea of settings to try to catch some action?

The t.5 flash duration of your Smartflash is much faster than 1/800th.

Which is why I think you should try it with what you have, because a SS to 'freeze motion' is a moving feast, depending on a number of variables.

 

[Faldrax]

Mark - as Phil says, the actual flash duration is much less than 1/200.

The reason you use a max speed or between 1/160 and 1/250 (depending on exact camera and triggers), is that for flash to work the camera shutter must be fully open at the instant the flash fires.

A camera shutter is actually 2 shutters - you start with 1 open and one closed.
When you trigger the camera, the first shutter opens, then after required exposure duration the second one closes.
But the shutter actually takes a bit of time to open (and close).

So if the shutter takes 1/230s (for example) to fully open, then if you had a shutter speed of 1/250, the second shutter is actually already closing before the first shutter has fully opened.

By setting the max shutter to 1/200, there is time for the 1st shutter to open, then the flash to fire, then the 2nd shutter to start closing - but since the flash is much brighter than the ambient light, you just see the scene as illuminated for that brief instant of the flash, and the additional exposure from the ambient light vanishes to black.

 

[markyboy.1967]

Given the above info i will try it this weekend. My camera is the D4s with tge Smartash 200x2 and an Elite Pro 300 head. I will try with the Elite Pro i think. Where should i start with the camera shutter speed? And should i be at close to full power on tge Elite Pro?

 

[Garry Edwards]

The SmartFlash 200 has a t.5 duration of 1/2700th and a t.1 duration of 1/900th - that's at full power, so as Phil says, shoot at full power and see what you get, it may well be enough. Just use ND gels over the flashes or an ND filter over the lens if you can't reduce your camera ISO enought to allow full power shooting.

If you're not happy with the results then consider the SuperFast, which has a t.1 flash duration of 1//20,000th, at minimum power.
As Faldras pointed out, just shoot at 1/200th - the shutter speed is all but irrelevant.

 

[Phil V]

Given the above info i will try it this weekend. My camera is the D4s with tge Smartash 200x2 and an Elite Pro 300 head. I will try with the Elite Pro i think. Where should i start with the camera shutter speed? And should i be at close to full power on tge Elite Pro?

The shutter speed needs to be below sync. It's relatively unimportant, if you use a high power on the flash it'll keep the flash duration short and the aperture small which also helps to knock out the ambient.

 

[mike weeks]

just because you have a short flash duration it does not follow that you will freeze the action, why? Because the exposure is made up of the flash and the ambient, so you need to keep the ambient low in relation to the flash so that the ambient is not powerful enough to record on the image.

Mike