Flash Exposure Compensation at Weddings

[NJMAN]

I just wanted to get everyone's opinion on using Flash Exposure Compensation and whether it is necessary for indoor and outdoor flash shots during a wedding ceremony and reception where flash is allowed.

What do you typically set FEC to when indoors vs. outdoors based on available/ambient lighting?

 

[Big Mike]

FEC may need to be changed for each shot...or at least every time the light or even composition changes. Assuming of course that you are using your flash in E-TTL mode.

Typically, you want a nice blend of flash and ambient light to expose you subject. For many, the ideal is when it's hard to tell, from the image, that flash has been used. This will often mean that using a negative FEC works to accomplish this. However, if there is something that is quite reflective (white wedding dress), it can throw off the E-TTL metering and you will get less flash exposure than you want...in which case you may need to use a positive FEC.

In darker situations, you need to consider blur. It may be hard to get a fast shutter speed (without resorting to ISO 1600 or higher)...in which case...the ambient part of the exposure may be blurry. The flash exposure, however, is fast and therefore probably not blurry...so you might want to use a positive FEC...or just use a faster shutter speed and no FEC...which will give you less background exposure but probably a sharper image.

It's not a simple issue and it takes practice and experience to get it down pat...especially in a fast & stressful environment like weddings. Believe me...I'm far from being a master at this.

If you haven't yet...check out the EOS Flash Bible

 

[NJMAN]

Thanks Mike. I am a particularly tough situation because the wedding I am going to be practicing on is this Saturday, and I didnt have time or money to get a faster lens yet (f/2.8 or faster). So, I am probably going to be using my 18-55mm f/3.5 lens for the reception most of the time because I am going to need a wider angle for group shots. I will also have my 580EX flash with a stroboframe bracket and diffuser/bounce on the end of it. The other lens I will be using is the 50mm f/1.8 in the church with no flash.

So, what would you recommend for FEC in this case? I can usually squeak out pretty nice focused shots when I do ISO 800, widest aperture (3.5 on the 18-55mm), shutter speed somewhere between 1/60 and 1/80, and sometimes even 1/50. I also usually underexpose by about 1/3 or 2/3 stop for a slight shutter speed advantage. Will FEC help me with shutter speed here and still give me a good mix of exposure for foreground and background?

And yes, I have read these articles a few times, except there is a lot of information to sift through.

 

[Big Mike]

Will FEC help me with shutter speed here and still give me a good mix of exposure for foreground and background?

Just figure it out as you go and you will be fine. Take a shot, check the histogram and adjust the FEC to suit.

The power of the flash is tied to the aperture. So if you shoot at F8 the flash will give you light for F8. If you change to F4, the flash will put out enough light for F4....so ignoring other factors...your exposure won't change. That's where FEC comes in. If you take a shot at F8 and it's too dark...then dial in +FEC. If it's too bright, then use a -FEC.

 

[NJMAN]

Just figure it out as you go and you will be fine. Take a shot, check the histogram and adjust the FEC to suit.

The power of the flash is tied to the aperture. So if you shoot at F8 the flash will give you light for F8. If you change to F4, the flash will put out enough light for F4....so ignoring other factors...your exposure won't change. That's where FEC comes in. If you take a shot at F8 and it's too dark...then dial in +FEC. If it's too bright, then use a -FEC.

Thanks! This helps a lot.