Need Some Flash Tips::::

[mikec]

Hey guys,

Looking some some quick and dirty tips for an event I need to cover next week. It's a local thing and I'm basically donating my time and using it as a learning experience plus I'm getting special access for some posistions for different angles etc...

Anyway I checked out the lighting on Monday night and it's terrible. I was getting about 1/3 sec at f3.5, ISO1600 which is way to slow since the event is an indoor climbing event. So I figured a faster lens still wouldn't cut it so a flash was my only choice.

I'm hiring a 430EX II for the night (trying to accomplise this on a budget) and I'm after a few pointers.

I'm going to bounce / difuse the flash as much as I can with a home made bounce card or diffuser. There isn't much opportunity to bounce the flash off anything else.

I'll be shooting manual, around 1/200th sec or faster with F stop and ISO to what they need to get sharp results.

Anything I should look out for or try?

Thanks in advance for any help you can provide.

Cheers,
Mike.

PS. Yes I know it'd be better to do a trial with the flash the night before but it's not an option at the moment, damn shoe string budget.

[pollen]

If it's like those typical high ceiling rock climbing type events, you'll be wasting your time with flash, better to get a f/1.4 or f/1.2 lens, that way you'll get a shutter around the 1/30 region and if you take it up to ISO 3200 you'll get at least 1/60 shutter, though it'll be a bit noisy.

With home made bounce cards/diffusers, unless you are drastically increasing the surface area of the light source, they will be not much different than just direct flash (if you can't bounce). The further away from your subject, the crapper the results will look when using flash.

Unfortunately your best bet is probably natural light unless you can bounce the flash off a wall though if I could I would probably bounce off a wall (and ditch the diffusers). At times the subject might be a bit too far away though. Flash is horrible as the subject distance increases though

[mikec]

Unfortunately I can't push up to ISO 3200. I don't think 1/30th is going to cut it either, I'll get lots of blurry climbers! The event is at night in a poorly light industrial shed, more or less.

I might be able to bounce the flash off the climbing wall but it's a light purple / grey colour which probably won't lend itself well to bouncing I'd imagine. Can colour cast from bouncing be corrected in PP with WB?

Any one else have any thoughts?

[swifty]

Wow.. that's some tricky lighting situation.
I'm trying to figure out where most of your stand point would be. I doubt you'd be dangling on a harness on the same level as the climbers so from below you're throwing light potentially an awful long way.
And you say there's not much opportunity to bounce either...

FWIW this is probably what I'd do.
-ISO: take it up as high as you/your cam is comfortable shooting. If results are only used as small web sized presentations, you can push it quite high.
-If all the competition is taking place around one wall, you have the advantage of knowing which wall you might be able to utilise for bouncing. Try to colour balance manually but I'd still shoot RAW to be safe. I would still avoid direct flash if possible.
-Open up aperture as large as you can. Here you gotta be careful to see how fast your cam will sync at. With fast syncing I believe you start to sacrifice your flash output ie. guide number goes down.
- Put your flash in rear curtain flash mode.
- Experiment with slower shutter speeds with rear curtain flash to increase ambient light - this introduce slight motion blur whilst the flash freezes the end position.

That's about all I can think of for now.

[jev]

-Open up aperture as large as you can. Here you gotta be careful to see how fast your cam will sync at.

Aperture has nothing to do with how fast your camera will sync. Keep shutter speed at 1/30 or so and try to balance the light.

- Put your flash in rear curtain flash mode.

That is useless with slow-moving objects like climbers (unless they fall down ). Better use first curtain so that you maximize the chance to have an okay position of the climber during the flash.

My advice would be:
- camera in manual
- shutter speed somewhere around 1/30 or so (depends a bit on how close you can get to the climbers - if you need a long telelens without IS, you might need to speed things up a bit!)
- aperture f/5.6 or so, depends mostly on required DOF. Don't go much larger or you'll end up with only half-sharp subjects.
- ISO as high as possible (mind the noise; if your camera is okay up to 800 ISO thna don't put it much higher!)
- bounce the flash if you can and if the flash can provide the power. If not, try to balance the ambient light as good as you can against the flash output and try to minimize shadows falling on backgrounds.

[Jimbo]

Your question reminded me of this Strobist.com article. His ideas may help you...

[swifty]

Aperture has nothing to do with how fast your camera will sync. Keep shutter speed at 1/30 or so and try to balance the light.

You are, of course absolutely right in that aperture doesn't affect flash sync. Sorry I should've elaborated further. What I meant to say is that in chasing high shutter speeds, the OP may be using high iso and opening up aperture so the shutter speed may exceeds the flash sync speed (or manually setting high Shutter speeds), typically around 1/200 or 1/250th for many DSLRs. And in doing so, you have to use high speed flash sync which reduces the flash's guide number.

That is useless with slow-moving objects like climbers (unless they fall down ). Better use first curtain so that you maximize the chance to have an okay position of the climber during the flash.

My advice would be:
- camera in manual
- shutter speed somewhere around 1/30 or so (depends a bit on how close you can get to the climbers - if you need a long telelens without IS, you might need to speed things up a bit!)
- aperture f/5.6 or so, depends mostly on required DOF. Don't go much larger or you'll end up with only half-sharp subjects.
- ISO as high as possible (mind the noise; if your camera is okay up to 800 ISO thna don't put it much higher!)
- bounce the flash if you can and if the flash can provide the power. If not, try to balance the ambient light as good as you can against the flash output and try to minimize shadows falling on backgrounds.

Again I'm no authority on rock-climbing but from my limited experience, climbers are often in longer periods where they don't move much (where slower shutter speeds should be fine), followed by short bursts of quick maneuvering for tricky lunges and overhangs. I would think some of the better action shots can be obtained during these peak action and perhaps 1/30 may not be enough.
My comment on rear curtain also refers to artistic use of motion blur during these peak action. Generally their movements are more predictable than eg. erratically moving ball sports players so peak action can be anticipated and timed with slow rear curtain sync.
DOF of course is also not just a function of aperture so without knowing what lens and what distance the OP is shooting at its hard to know the appropriate aperture. But it seems in this scenario where light is the limiting factor, if the shot is tightly framed its unlikely you'd need a lot of DOF. And if its a wide shot showing climber and wall, then DOF shouldn't be a huge issue so I'd take the extra stop of aperture where possible.
Cheers

[bmxbandit]

How did the shoot go? What did you end up doing?

There are a few things that you could (for next time), depending on what the images are for.
There is the, I-have-nothing-to-lose mode where you set the shutter to what you think you need, open up the aperture, set the ISO to whatever, and shoot in RAW. In post, make the images black and white, and slide up that exposure and brightness control. Then, if the image is not too bad, you can use some noise controlling techniques to fix things up.
Here is an example of a picture that I have rescued.

The original


Moving those exposure and brightness sliders


And reducing the noise as per this post on my blog


Option 2, see if you can borrow a camera that has good ISO/noise ratio. So you can shoot at ISO 6400 with no qualms.

Option 3, borrow an SB-26 or something that has an optical slave on it, and shove it over the side somewhere. Then you have your direct flash, and another light source coming from somewhere else.

Refining this a little, you can have two strobes off to the side triggered via optical slaves, and use your camera's pop-up flash to fire them.
I had to do this once when I stupidly left my transmitter at home. (Turned out that I just didn't look hard enough in my bag!)


Hope this helps for next time.

[bmxbandit]

... For next time, a more details explanation to option 3 -- care of strobist.

[kiwi]

did we get across the concept that the flash freezes the action, not the shutter speed ?

[mikec]

Wow talk about digging up an old thread....

I think I've come a fair way since I posted this thread now. I'm using a 580EX II these days off camera with a set of PW's. Haven't had a chance to use them in this type of situation again but I think I'd be right now that I'm getting the hang of balancing ambient with flash.

[bmxbandit]

Cool.

[beckett5361]

Glad I'm not dealing with that under pressure, strobist has quite a few rock wall shots on it, they all seem to light the wall from behind objects, either climbers or equipment on the ground, good luck with it. Love the photo recovery and noise reduction information too thanks, I'll try that out.