Nightski

I just got a 550EX flash for my Canon Rebel XTI. No instructions. I found a manual online, but I think I am doing something wrong, because when press the shutter button the aperture stays open a long time after it flashes and overexposes the photo. Am I suppose to set the flash up somehow so it works with my camera better?

robert-photos Loc: Chicago

What camera settings are you using?

Nightski

Manual F4.5, Exposure 0...am I supposed to have the WB on flash?

Nightski

I think I figured something out. There is a select/set button. If I push that and then push + or - then it goes from 1/1 to 1/128. At 1/128 the flash isn't blowing out the photo anymore. I wonder how you know exactly where you should have that set for the different F-stops?

robert-photos Loc: Chicago

If you are on camera manual what is your shutter speed.

Also, are you shooting the flash on manual or ettl?

WB doesn't ~ affect the exposure.

jdubu Loc: San Jose, CA

The 550 can be ettl or manual. It depends on the mode you set it for. It also is capable of master and slave modes to either direct other compatible speedlites (master) or be directed by another flash in master mode (slave)

Ettl is where the camera and speedlite talk to each other to come up with the proper exposure. You can dial in plus or minus compensation on the camera to increase or decrease the amount of flash beyond what they decide is the proper amount of light.

When you see the settings for power, 1/1, etc. that is manual mode and you are setting the power output manually by selecting one of the power levels. Remember, the speedlite is not actually putting more power out the brighter you set it. It is only increasing the time period the flash is energized.

Therefore, a 1/1 or full power setting means it is sending light out for the maximum length of time. A 1/2 setting cuts the time it is sending light in half, and so on.

Read the on line manual and have fun with it, experiment and see what happens. I still have 550's in my bag and they work well with the 580IIs when I want to fill large areas or need a pop of light somewhere. You can't go wrong with them.

As I recall we discussed speedlites before... I think you made a great choice for learning with and it will serve you well for a long time.

PhotoGator Loc: Florida

You camera Scene setting must be set to Flash.

Canon 550EX flash manual
http://mfaphoto.schoolofvisualarts.edu/pdfs/manuals/Canon_Speedlite_550EX%20.pdf

WAL

This is a quick answer. I have spent some time looking at this and will gather what I’ve found and send it later. For now Set the camera to shutter priority (T) mode and set it to 200/sec or less.
The problem is that the camera is trying to balance the environmental light with the flash. The idea is to avoid the usual flash look of a bright foreground with just a black background. What happens is that when the existing light is low the shutter stays open far too long in an attempt to balance the light.
It’s a case where automation goes too far.

PhotoGator Loc: Florida

Another thing your Shutter Speed should be at least equal to your Focal Length.

FL = 50 ------> SS = 1/50"
FL = 100 ------> SS = 1/100"

gypsylarry Loc: Lancaster, PA

I have the 550 canon flash and use it on both my 60D as well as my 5D. Put the flash on ETTL mode (throught the lens) until you get better acquainted with it's many uses.
If you are in a mode other than Auto, use your shutter speed setting at 1/250. This is what speed the flash works at. You'll find it sync to the camera best at this speed. If you need more light, you can increase the flash with the big button in the middle of the back, or increase your aperature, or increase your ISO.
Hope this helps.

rpavich Loc: West Virginia

How long are we talking?

the aperture and flash are separate....in other words...if you have the flash on "manual" then you are adding what YOU think is the right amount of flash...if you set it to ETTL...then the camera is deciding what is the right amount.

Do you have it set for ETTL or manual?

PM me if you want me to walk you through setting your flash up manually.

Coker Loc: Havana, IL

Test it on the (P) setting.. Please try again.

RocketScientist Loc: Littleton, Colorado

Hit the mode button until it says ETTL on the display. Master/Slave switch should be OFF. Put the camera on P for starters. From the menu on the camera you should be able to clear the custom functions that may or may not be set on the flash. And, of course, RTFM - Read The FINE Manual.

rpavich Loc: West Virginia

Well...except for the auto-ETTL mode...here is one common way to use that flash in manual mode.

Set your camera for a manual exposure that is correct for the scene. let's pretend:

ISO 1200
ss = 1/60
f/4


Set the shutter speed to remove two stops of exposure.
Result:
ISO 1200
ss = 1/200
f/4


That means that your image will be 2 stops underexposed.

Now turn the flash on and set it to 1/4 power.

Take a shot....how is it? Too hot?

Turn it down to 1/8 power.

Take another shot. How is it?

Etc.

The flash is just adding the key light and the ambient exposure is adding the shadow levels.

You can do the same with ETTL...just do it all except you don't change the flash power to adjust, you change the Flash Exposure compensation.


Here is a post in which I explained it and showed examples

http://www.uglyhedgehog.com/t-117173-1.html

And here is David Hobby explaining it..(very good post)

http://strobist.blogspot.com/2007/09/lighting-102-33-balancing-flashambient.html

Nightski

Thank you rpavich....I go look and then ask questions :)