Fill flash

[brian_byrne1]

Hi I'm new to the forum. I've got a Canon 30d with a 580ex speedlite. I've been

trying to understand fill flash and slow synch flash for weddings but am not

grasping it. How you you set fill and slow synch flash on the 580 ex

[derek_linney]

The gospel on EOS Flash is <a href="http://photonotes.org/articles/eos-flash/">http://photonotes.org/articles/eos-flash/</a>.

 

 

I just put the camera into Av select my aperture. Set the flash exposure compensation to -2. And it all looks after itself. This works fine provided there is sufficient ambient light to avoid very slow shutter speeds (i.e. you really are using the flash as fill).

[cliff_henry]

Then Photonotes.org site should be helpful as well as the followering:

 

 

http://planetneil.com/tangents/flash-photography-techniques/

 

http://strobist.blogspot.com/2006/03/lighting-101.html

[picturesque]

Cliff's sources are great. Also do searches in the wedding forum re fill flash and dragging the shutter. Lots of good stuff there.

[alan_myers]

Hi Brian,

 

Some people are just plain grumpy on Monday mornings. ;-)

 

Yes, read those tutorials by all means.

 

However, you may be able to simplify things a bit and I think I noticed a bit of incorrect advice.

 

Now, I use three 550EX with my 30D (and 10D and EOS3s), not 580EX in particular, but I think the general functions of 580EX are pretty much the same. I also try to avoid shooting weddings, but occasionally get talked into it.

 

When using Tv or Av auto exposure modes on your 30D, your flash should automatically do fill, rather than full output. I seem to recall it sets about -1.25 or -1.5 stops. So you may not need to dial in any additional flash reduction at all, in these particular modes. Try it and see what you think.

 

Personally, unless there pretty variable ambient lighting I usually switch to M and use a separate, handheld, incidence meter to set the camera's exposure. The flash will think it's the dominant light source whenever the camera is set to M, so here you *do* need to dial in between -1 to -2 stops, whatever looks best to you. I usually start about -1.33 and tweak it from there, using a little more reduction for closer subjects, a little less for more distant ones.

 

Using M (manual) takes the internal camera meter out of the equation. Particularly with the classic, difficult-to-meter examples of a bride's white dress and a groom's black tux. An incidence meter measures the light falling onto the subject, not what's being reflected from it (the way a reflective meter does, including all camera TTL meters). So, it's more accurate in situations with overly light or dark subjects, and I prefer it to seeing the internal meter hunting all over the place and trying to guesstimate what compensation to dial in on the camera.

 

Leave the flash in ETTL with either method, so that the fill is still metered and controlled automatically.

 

Using M also gives you more complete control over the shutter speed. You can set the flash to High Speed Sync if using speeds above the 1/250 sync on your camera, but the flash's reach will drop off quickly when you do this. Via a custom function you can set the camera to default to 1/250 when using flash in Av, however I never do this and leave the Cfn set to "Auto". I often use flash with both higher and lower shutter speeds, balancing it with the ambient light.

 

It all sounds complicated, but in truth for me using M mode seems simpler. I set it and forget it so long as the ambient light doesn't vary. Check the histogram every so often, and re-meter every once in a while, just to be sure. Any time you change locations, or a cloud goes over the sun, you'll need to re-meter and reset the camera.

 

You can use the camera's internal meter to arrive at M settings. Aim it at an 18% gray card or anything that approximates a gray card pretty well, to get the most accurate metering. An actual gray card can be handy setting custom white balance, too.

 

Finally, if you shoot RAW, you can tweak exposure quite a bit, later on in Photoshop (or whatever). It's best get the exposure fairly accurate, but this gives you a fallback if something is off a little.

[bill_mussett1]

I strongly second Nadines suggestion to search the Wedding Forums; especially the Technical

sub-forum.

[William Michael]

. . . search the Wedding Forums (NOh & BM)

 

Ditto. Excellent information there.

 

Key words: `Fill Flash` `Dragging the Shutter` `Flash Fill`

 

WW

[pkallos]

You can check out a post I just did asking for critique on fill flash. I was using aperture priority with a Canon 30D. I'm not 100% happy with the pictures, and maybe someone will have more info there.

 

Manual mode is nice, but unfortunately for the pictures we took we were constantly moving around into different lighting conditions, so that wouldn't work for me.