Help this noob out with his flash

[Robin Usagani]

So I bought 550EX of craigslist. If I shoot in AV mode in lower light condition, the camera automatically set my shutter speed to a really slow speed. Isnt my camera smart enough to figure out that there will be more light from the external flash? It seems that the camera set the shutter speed based on the existing light without the flash. Thanks!

 

[MrBarney]

Deja Vu?

http://www.thephotoforum.com/forum/...um-photo-gallery/208881-link-flash-dummy.html

(the thread title is a little unfortunate!)

Av mode will ALWAYS expose for the background at ambient light levels - Auto Slow Sync.

 

[gsgary]

Deja Vu?

http://www.thephotoforum.com/forum/...um-photo-gallery/208881-link-flash-dummy.html

(the thread title is a little unfortunate!)

Av mode will ALWAYS expose for the background at ambient light levels - Auto Slow Sync.

I don't think so

 

[Robin Usagani]

Deja Vu?

http://www.thephotoforum.com/forum/...um-photo-gallery/208881-link-flash-dummy.html

(the thread title is a little unfortunate!)

Av mode will ALWAYS expose for the background at ambient light levels - Auto Slow Sync.

So dont use the AV mode?

 

[Bitter Jeweler]

that depends...

 

[Josh66]

Deja Vu?

http://www.thephotoforum.com/forum/...um-photo-gallery/208881-link-flash-dummy.html

(the thread title is a little unfortunate!)

Av mode will ALWAYS expose for the background at ambient light levels - Auto Slow Sync.

So dont use the AV mode?

With flash, yes - don't use Av. Unless you just want fill flash, with the primary light source being the ambient light.

edit
I posted this in the other thread, but I'll post it here too:
http://photonotes.org/articles/eos-flash/

It's a 3 part article/manual that will tell you how to do anything you could possibly do with flash on a Canon body.

It's long, but the index is good, and it's probably the most in-depth flash guide you'll find on-line. Tailored to Canon users too, so win-win for you.

 

[MrBarney]

Deja Vu?

http://www.thephotoforum.com/forum/...um-photo-gallery/208881-link-flash-dummy.html

(the thread title is a little unfortunate!)

Av mode will ALWAYS expose for the background at ambient light levels - Auto Slow Sync.

I don't think so

??

Perhaps I should have clarified. Canon EOS digital cameras, such as the one the OP asks about, always expose this way in Av mode. It's in the manual, it's in the link and it's in the link O|||||||O posted:

[FONT=Verdana, Arial, Helvetica, sans-serif][SIZE=-1]In Av, night and Tv (shutter speed priority) modes the camera meters for ambient (existing) light and fills in the foreground subject using the flash. It does not assume that the primary light source is the flash, and therefore the shutter speed it sets is the same as it would set if you weren’t using flash at all. [/SIZE][/FONT]

The only way I can see around it is C.Fn I: Exposure 3: Flash sync.speed in Av Mode. Personally I don't see the point as if you're going to do this, why no just switch to manual and set the shutter speed yourself depending upon what you want to achieve?

 

[MrBarney]

So dont use the AV mode?

I agree with Bitter - it depends. Av mode is perfect for portraits at night if you have a stable platform for the camera and want fill flash. It also works well with second curtain sync.

If you want to use the flash as the main light, either because it's too dark and you're getting blurry pictures, or because you want to underexpose the background, then it's no good at all. Either use (P)rogram or go to manual and set the shutter speed.