Canon 430ex ii

[Ballez]

Hello,

Little while ago a bought a 430EX II flash unit, I'm using it with canon 40D EF-S17-85 MM. I'm having hard time using it in dark light, most of my images are pretty grainy. I am probably doing this wrong, for me to achieve a descent image that is not blurry I have to go a high ISO 400 to 640 and then choose a fast shutter speed but like I said little better focusing but way to grainy.

Please help,

thanks!

[OsmosisStudios]

Remember: you can crank the shutterspeed up to the max and it wont affect how the flash lights the image (only the ambient light). The flash is affected by the aperture of the lens and, to a lesser degree, the ISO used.

Were you bouncing the light? if so, off what? If not, why? How far was your subject?

[inkista]

Short answer: switch the camera to P mode.

Slightly longer answer: if you use Av, you can set the custom functions so that the shutter speed is forced to be higher, and balance you more towards flash than ambient. The default assumption by the camera's AE system is that if you are in Av or Tv mode, that you want the flash for fill, and that most of the light will come from the ambient.

Long answer: every flash photo combines two sources of illumination: the ambient and the flash. You can balance those two light source against each other any way that you want, so there's so single combination of "good exposure", as there is with ambient. You can go all the way from no-ambient/all-flash (black background, lit subject), to all-ambient/no-flash.

The best way to control this balance is to use the camera in M mode, and control the balance with your shutter speed. (read: Dragging the Shutter). The higher your shutter speed, the less ambient you'll have. HOWEVER. Your camera also has a max. sync speed, probably 1/250s. If you go faster than this, you'll have to use high-speed sync, and the power output of your flash will be reduced.

Your ambient exposure is controlled by iso, aperture, and shutter speed. This you know (or should know. If you're not comfortable shooting in M, yet, I'd say put away the flash and practice ambient-only photography for a while. It won't take long to master).

Your flash exposure, however, is controlled by iso, aperture, power output, and subject distance. Note how shutter speed is not in that list. This is because the flash burst duration is shorter than your fastest shutter speed.

You also need to know your flash has two modes: eTTL and M. eTTL is kinda-sorta like Av mode on your camera. Just as Av on the camera can slide your shutter speed around to match what the metering gives, eTTL will slide your flash's power setting around to match what the eTTL "preflash" metering gives. With eTTL, your camera tells the flash to send out a "preflash" burst of a known brightness, meters it, and then sets the flash power to where the AE system thinks it ought to be for good subject illumination.

So, if you're using eTTL, you can change your iso and your aperture, and you may not see any exposure difference at all, because the flash's power output will have been adjusted to match the change you made. This can be a good thing, or an incredibly frustrating one. Which is why there's also FEC. Just as EC lets you bias the metering in an automode on the camera, FEC lets you bias the flash output in eTTL.

And in M mode, you simply set the flash output level and it sticks. Just as you use M on the camera for control and consistency, you can use M on the flash to do the same thing.

You have to understand that your meter can only measure the light that's in the scene. With ambient photography, this is a fine way to set your exposure settings. But with flash, you have to mentally envision what adding the flash will do, and then bias the metering taking the flash that isn't in the scene yet into account. This is why most of us use M on the camera with flash: because we'll start out underexposing the ambient anywhere from 1 to 5 stops, to get a specific flash/ambient balance.

[Ballez]

Thanks guys, I'm off to practice!

[karencphoto]

Originally Posted by inkista

You have to understand that your meter can only measure the light that's in the scene. With ambient photography, this is a fine way to set your exposure settings. But with flash, you have to mentally envision what adding the flash will do, and then bias the metering taking the flash that isn't in the scene yet into account. This is why most of us use M on the camera with flash: because we'll start out underexposing the ambient anywhere from 1 to 5 stops, to get a specific flash/ambient balance.

First, thank you. Your post is amazingly helpful. I just bought a 430EX off KEH. Trying to figure out how to use it and feeling like the village idiot in the process. I shoot manual on my 60D normally, but was starting to think I needed to shoot green box using the flash. (Yes, I feel that dumb.)

So, I think I am starting to get this. Please correct me if I'm wrong!

1. Flash in ETTL mode.

2. I set up my shot just like normal, using the meter in-camera to read the ambient light.

3. Underexpose a bit to account for the flash, which for me, is generally messing with shutter speed.

4. Get a half decent shot.

Still trying to wrap my head around it... I just did two test shots - one underexposed and the other exposing for the ambient light. The underexposed definitely turned out better. The exposed for ambient was way too harsh, even with the flash angled 45 deg.

[ddr]

while ettl is definitely an excellent piece of technology in many situations, you don't have to use it. after several experiments, try playing with the flash power manually, and its zoom settings.

you also don't have to underexpose the ambient. perhaps that's the kind of look/style you like. in many situations, the flash is used for fill and not the main light.

[inkista]

Originally Posted by karencphoto

1. Flash in ETTL mode.

This is like saying "put the camera in Av mode". Sometimes it's right, sometimes it's wrong. You use e-TTL if you need the camera to automatically adjust the power setting for you. You use M if you want to take charge of the power setting for yourself.

2. I set up my shot just like normal, using the meter in-camera to read the ambient light.

You just need to know where the ambient is, first.

3. Underexpose a bit to account for the flash, which for me, is generally messing with shutter speed.

Again, this is like saying, "to expose properly, I always put the needle on 0." This may be ballpark, but it won't always get you what you want, and it really depends on what effect you're going for, what kind of flash/ambient balance you want, and what the light from your flash is going to illuminate. If the light from the flash is controlled/flagged/gridded/snooted NOT to hit stuff, you may not need to do this. It's like choosing whether or not you want a silhouette in ambient shooting. It all depends on the light and what effect you want to achieve.

4. Get a half decent shot.

Actually, I think this is step 0: compose the shot well. Without a good shot to begin with you got nothing.

The exposed for ambient was way too harsh, even with the flash angled 45 deg.

Actually, this could be a matter of judgement, and how you use the flash. Just angling the flash up 45° or 90°, but still having it pointed straight ahead is still not using your bounce to best effect. Choose the light direction, this is what the swivel is for. Wherever you'd be putting a softbox? That's the spot at which your flash head should be aimed.

Sometimes, when you're power-limited, letting the ambient do all the heavy-lifting can be a good technique, too. Think through the light. Don't just try and follow a formula. If you don't understand what's happening, then when the formula doesn't work, you're going to be up a creek.

[ddr]

Originally Posted by inkista

Think through the light. Don't just try and follow a formula. If you don't understand what's happening, then when the formula doesn't work, you're going to be up a creek.

should be stickied

[karencphoto]

I think I still have a million questions, but I'm going to reread your advice tomorrow when my mind is fresh. Been a long day here.

Thank you SO much for taking the time to reply - both of you. Much appreciated.

[inkista]

No problem. I'd also recommend bookmarking Neil van Niekerk's Tangents blog. It's chock full of great information on using on-camera flash. Start with his Flash Photography Techniques (which have been collected and expanded into a book), and then go through the flash articles.

Then you might be ready for the Strobist and off-camera flash.