Motorsport and flash photography

desantnik

desantnik

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Vlad
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Ok, I am a 1 week old noob at flash and need to ask a question, so be patient!

Did a rally last weekend and used my shiny new flash a fair bit and discovered how this freezes the action - in particular wheels and thats a no-no in motorsport togging.

The problem I believe is actually the duration of the flash burst itself - I've read its very fast and I guess when there is little or no other light present regardless of the camera's shutter speed, the light was only there for a stupidly short time, hence the action freeze.

Have I got this right?

Would moving up to hi-speed sync (FP) mode which uses pulses of light rather than a single flash help? Unless this overall duration was more than about 1/125th or 1/250th at the most, it probably won't make much odds though.

I was using rear curtain sync (obviously not with FP...), is there a better bet than this?

Another idea today was to use a slow shutter with a series of repeated flashes - which should light the subject and allow the wheels to be in different places with each burst.

Anyone got any tried and tested ideas?

I am off to shoot a night race this weekend and would rather not just have frozen cars. Failing such a solution I'll just try some whacky stuff instead :D
 
No not really.
 
kalibre said:
erm, isn't pointing a flash at drivers in a night race a bit dangerous? :thinking:
Click to expand...

Not unless they're looking straight at the photographer, the light will be in their peripheral vision.

High speed sync will probably freeze the action even more as your shutter speed will come down too. This will also have the side effects of reducing the ambient exposure unless you open up the aperture to compensate (at the expense of DOF) and reducing the output power of the flash. You might also get more ghosting unless your panning is spot on due to the longer duration of the flash. I'll admit it's not something I've tried but it's what I would expect to happen.

I don't know where your rally is but you might be better off trying to find a street light or floodlights where the cars pass by and use the ambient lighting from them to give you enough light to blur the wheels.
 
Cheers Kev,

This Saturday is not a rally... its a "mini Le Mans" style event at a race circuit.

I've shot it a few times before and each time I've had random results, was rather hoping to go with something more predictable! :D

I think you are right about the highspeed sync, I *think* I tried that at last week's rally - but its hard to tell because the poxy flash data isn't saved with the exif - how annoying is that!

Ok, so its multiple bursts on a single exposure to try... failing anyone actually being able to tell me based on experience or science, I'll probably have to go out and try testing it in a car park one evening this week, if I can persuade a friend to hurtle around the car park at "race pace" :D (NB thats a joke before the fun police pipe up)
 
I'd go really long exposure with rear curtain flash and see how that works...
 
Yes, that is what I've done before, it doesn't really give the equivalent of a daylight panning shot though...
 
Is there a particular effect you're after with the flash? There's a lot of good night time le mans type stuff on here using what available light there is. I'm not sure flash is going to add that much in this particular situation tbh without seeing an exaple of what you hope to achieve.

As for predictability it's going to be all about shooting manual camera and manual flash and seeing what happens.
 
Well, the place in question will be dark - pretty much total dark in the section I want to shoot at (just as well, because elsewhere are nasty sodium lights...there goes all my colour!).

Last time out I was shooting things like this:

1954221697_0c550f071a.jpg


There were a couple of challenges with the kit I had last year, the main one being focus on a subject which isn't lit! I think based on last weekends performance should be overcome with my new kit.

Anyway, ignoring the fact that my example above is lit additionally by another car following it, am looking for that kind of lighting effect, but with some wheel blur...
 
I've got access to that Mike :D

Can you explain how this would help though? I've used off camera flash a few times for motorcross (daytime) and other than getting better lit subjects and some real punch to the bikes, I can't say I can think how it might offer motion blur?

Unless I suppose I had a line of flashes setup to flood a strip of track and fired them one after the other with a delay between them?

That sounds a little OTT :D
 
Never really works for me. It either freezes, losng the atmosphere, or does this;
n545295264_4714985_5799.jpg


Although that's all very nice it's not a daylight panning shot. I pretty much packed it in aftera couple of hours, not much you can really do til dawn.
 
What did you do with that one Jake? Can't see the exif and no idea about how the flash was setup..
 
Ok, just looking at my SB900 manual, the fastest rate of repeat flash is 100Hz, thats 100 flashes per second or a flash every 1/100th of a second.

Therefore to get more than one flash into an exposure I would need a shutter speed of longer than 1/100th of a second, in fact I'd need to be at 1/50th to get two in...

That's going to challenge my panning ability somewhat!
 
The other prob you are going to come across here is flash recharge/refresh rate. Can it recharge twice in 1/50th?
 
That depends on how much the output is... obviously it can't at 1/1 but maybe at 1/16.

The fact that it can be set to 100Hz suggests that a refresh rate is possible... the manual does give a table for number of flashes at various frequencies and power settings.
 
desantnik said:
I've got access to that Mike :D

Can you explain how this would help though? I've used off camera flash a few times for motorcross (daytime) and other than getting better lit subjects and some real punch to the bikes, I can't say I can think how it might offer motion blur?

Unless I suppose I had a line of flashes setup to flood a strip of track and fired them one after the other with a delay between them?

That sounds a little OTT :D
Click to expand...

Not tried it myself, I'm just thinking along the lines of illuminating part of the car from a different angle to the wheels.

Failing that, try experimenting with different levels of manual flash. If you're shooting ettl it's going to be all over the place trying to light everything up.

And I don't think if you're shooting into virtual pitch blackness you'll get much luck, you will need some sort of ambient light I think.
 
desantnik said:
That depends on how much the output is... obviously it can't at 1/1 but maybe at 1/16.

The fact that it can be set to 100Hz suggests that a refresh rate is possible... the manual does give a table for number of flashes at various frequencies and power settings.
Click to expand...


I agree but then the distance the flash travels is considerably less.


Here is a thread I asked a few questions about a while back. Have a read, I dunno if you get any info you require from it.

http://www.talkphotography.co.uk/forums/showthread.php?t=86517
 
Actually, one of the links from your thread did help.... and a further link from that helped A LOT!

I think now FP mode might give me the answer... had hoped to try it out before Saturday but looks like I can't... anyway will report back with my findings, successes and failures next week :D
 
Well, I tried and tried but couldn't find anything that would give you anything but frozen wheels... unless the flash didn't actually hit the subject...

Did find a really mad effect though... I tried the repeat flash with a panning shot. Was looking at it this morning and thinking "damn, still frozen" when I suddenly thought "thats strange two media togs stood next to each other"... then I looked again... there is two of everything static and one car.... hadn't thought that would happen!! LOL
 
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