580EX Overxposed

[aWebJam]

I have a Canon 50D. I was doing a few test shots last night with a used 580EX before I purchase it and I can not get a decent picture with it.

I first set my 50D to AV mode (F8) ISO 400 and the flash to ETTL. I was shooting indoors with adequate lighting All the shots were overexposed. I then played around with different AV and ISO settings with no luck

My next step was lowering the flash comp.

First try was 1/3 stop still over exposed
second try 2/3 stop over exposed but not as bad as the first
Third try 1 full stop and the picture was underexposed by quite a bit

I then set the 50D to Auto mode and left the flash in ETTL mode and the shots were no better still overexposed by quite a bit.

I read the manual and cannot figure out what could be causing the overexposure. Anyone have any ideas or suggestions?

thank you,

[inkista]

Get your camera out of Av and into Manual. Or, if you just want the speedlight to act like the built-in flash of a P&S, you can shoot in P or adjust the C.Fn.I-7 to 1 or 2 to bring the shutter speed up.

Take a look at this article which explains how the flash will behave in the different camera shooting modes.

Basically, the assumption is that if you're using a speedlight in Av/Tv mode, you just want the flash for fill, so the exposure is going to be set pretty much as it would for ambient (i.e., the available light), with the flash burst to illuminate your subject shadows. If you tell the camera to use a faster shutter speed, you will effectively be relying on the flash as your main source of illumination, and you'll have much less of the ambient.

You will, essentially, have robbed yourself of the capability of balancing the flash/ambient the way you want it. Shooting with the camera in M will give you much more control over this, even if the flash is in eTTL mode.

[aWebJam]

Thank You Thank You Thank You Inksta.......both articles are an excellent resource. I cant wait to get home and try out the flash again...

thanks again

[LoveDSLR]

Originally Posted by aWebJam

I have a Canon 50D. I was doing a few test shots last night with a used 580EX before I purchase it and I can not get a decent picture with it.

I first set my 50D to AV mode (F8) ISO 400 and the flash to ETTL.

Try TTL instead of eTTL. It does the trick with my 5D Mk II.

[inkista]

You're welcome! Shooting with flash is more complex than available light, but it can be much more rewarding. The resources I'd recommend for learning about this stuff would be:

POTN's Flash Photography 101. A quick spin through the basics, useful for us 50D shooters, because it's written from a Canon hardware perspective.

Planet Neil's Flash Photography Techniques section (it also comes in book form; and the rest of the blog is great, too). van Niekirk is a wedding photographer and his knowledge is all about on-camera flash and eTTL, although he also discusses off-camera and video lights.

The Strobist. It's the motherlode on off-camera lighting techniques and a lot of good basic flash knowledge, but it's a blog, and so it's not organized as cleanly, nor is it as basic as Planet Neil, so I'd recommend going here second. Also, you may want to feel your way through the "On Assignment", "Flash 102" and "Flash 101" sections, more or less in that order, although a lot of folks will tell you Flash 101 and then Flash 102. When Hobby initially wrote Flash 101, he assumed most folks reading were professional pjs with basic flash/lighting knowledge who just wanted to figure out how to get the light off-camera. Between that and 102, he realized he was also attraction a number of complete tyros who knew nothing about flash at all, so 102 sort of "wraps around" 101--it starts off more basic, and then bypasses it to more advanced material. So, my recommendation is to start with 102, when it gets confusing, switch to 101, then go back to where you left off on 102.

And for reference:

The Strobist Flickr Group. A very lively active community that will have more research on hardware and hardware combinations than you can shake a stick at. Using it for learning isn't so great because information comes in a bewildering blitz, but for look-up, it rocks.

The "EOS Flash Bible" (where that article on the different modes came from). Ditto the look-up note, 'cause it's more of a historical overview of EOS flash equipment and contains a lot of "film-only" information, and it's about 100 pages when you print it out.

[Doug Pardee]

Originally Posted by inkista

The "EOS Flash Bible" (where that article on the different modes came from). Ditto the look-up note, 'cause it's more of a historical overview of EOS flash equipment and contains a lot of "film-only" information, and it's about 100 pages when you print it out.

I haven't checked recently, but as of a couple of years ago that site was getting very out of date. It was oriented toward the original E-TTL and the earlier systems, and had little information on E-TTL II.

What information it does have on E-TTL II isn't particularly useful. I would characterize it as mostly misleading and occasionally downright incorrect.

It's a great site for the older systems, and to get a general overview of Canon flash systems. But when it comes to the details of modern E-TTL II cameras and flashes and how to use them, it can be more misleading than helpful.

[inkista]

Different squids for different kids. For me, the bible has been useful. And that "EOS Flash Confusion" section has come in particularly handy.

But I do agree that it can be extremely tricky to pick your way through the sea of information to what's actively relevant to a dSLR shooter, which is why I tend to recommend it only as a look-up reference, and more specifically for someone wanting to know about older flash tech and how compatible it may be with current equipment.