Shooting Sports with Flash

[showtm490]

How do you shoot action sports (mx, autocross, etc) using a flash and still using a speed over 200 to stop the action?

[Songman45]

Bright daylight using flash as fill? Daylight as main? Night time? Be more specific about what it is you are trying to accomplish here and how much flash you are packing. Bear in mind, shutter speed has to do with flash photography than ISO and aperature.

[showtm490]

I'm using a Canon Rebel XT with a Sunpack 383 and the 70-200 f4. I'm looking to use it for fill light during mid-day sun and during the evening hours. Also I'm wanting to use f4 to blur out the background.

[Jacco]

In the daytime, with flash as fill, 1/200th won't be enough for pin-sharp moving subjects. You will need a camera with a faster sync speed.
In the evening, when flash is the main light, 1/200th will be enough, because then the effective exposure time is the duration of the flash (the actual shutter speed plays no part as long as it's 1/200th or less). The duration of the flash is anything between 1/1,000th and 1/20,000th of a sec. More than fast enough to stop any sports action.

[tdodd]

Originally Posted by showtm490

I'm using a Canon Rebel XT with a Sunpack 383 and the 70-200 f4. I'm looking to use it for fill light during mid-day sun and during the evening hours. Also I'm wanting to use f4 to blur out the background.

I would think your best bet is to practice panning with the action. That will automatically get you a blurred background (and foreground) but should keep your subject sharp. 1/200 should easily be fast enough, maybe even too fast in fact, if you want to emphasise motion.

To use flash faster than 1/200 with your camera you will need a flash gun with high speed sync (HSS). Then you can choose any shutter speed, but the power of the flash will be reduced and the flash duration will match your shutter speed. On a bright, clear, sunny day, at 100 ISO and f/4 you will need a shutter speed of around 1/1600 to get a correct background/ambient exposure. Your flash will be very limp at a shutter speed like that, even if you had HSS. You could add an ND filter to reduce the ambient light and enable a slower shutter speed but then the light from your flash will be weakened equally b ythe filter.

I think that if you want to use fill flash you're going to have to shoot at your max sync speed and either choose an aperture to fit the ambient or add an ND filter. The flash will just have to do the best job it can. Otherwise, don't shoot against the light but instead just pan and forget the flash. Let the panning action be the source of the blur, as much or maybe more than the aperture.

Here's a shot of mine taken last Sunday. This was shot at 190mm. Shutter is 1/100 and aperture is f/16. 100 ISO, no flash. EXIF is intact. Unfortunately I had some fencing in the way, which has been picked up by the large DOF, but I could not open up the aperture without losing my creative 1/100 shutter speed. The solution would have been to add an ND filter but I did not have one..... or chop down the fence

[showtm490]

thanks for the advice. i've thought about the panning so i'll try it out.

[tdodd]

Good stuff

Just a word of warning - in my limited experience panning is a skill that improves with practice. Maybe you will be a natural. I'm afraid I'm not. I don't shoot motorsports often, so I always get rusty in between events. I can see the quality of my shots improving as the day progresses. The first few hundred are mostly very dodgy. So if you try panning and it doesn't work out too well, don't lose heart. Maybe raise the shutter speed a little and keep trying. As you improve you can slow the shutter speed again.

If you pan with the 70-200 then set IS to mode 2, or turn it off altogether. Try using your fastest drive speed and shoot short bursts - say 3-5 shots in sequence. You may find that your first shot in each sequence is a bit rough, as you first depress the shutter button, then a few better ones, and then a dodgy one as you release the shutter button.