550EX AF-assist with 40D

[FireRob]

Hello all, I am new to this forum and have found some very helpful topics. Thank you to all you active members out there who are making this site a very valuable resource.

I have recently upgraded to a Canon 40D (from a D30) and have been content with many of the features so far. That is until I try to use my Speedlite 550EX with the new camera body. I have found that Canon apparently "nerfed" several of the features that I have become accustomed to. (First it was the second curtain sync setting in the camera that I was able to work around within the flash.) Currently I am baffeled about why I can not get my AF assist beam to emit from the flash. Is this another issue of incompatability with the "older" Speedlites or is there some trick that I am missing? I have set the in camera c.FnIII:5 "AF-assist beam firing" to both 0:Enabled and 2:Only external Flash emits with no sucess.

Is anyone else haveing this issue with the 550EX and the 40D? Can anyone walk me through how to get the AF-assist beam to work with my 40D?

What I am affriad of is that Canon is trying to get me to go out and buy another flash (580EX II) even though the one I have is perfectly good.

Thank you all for your kind help and I look forward to your resonse!
-Rob

[CliveyBoy]

The 550EX should work fine with the 40D!
It's C.Fn 3 should be on 0.
AF in One-shot mode.
Camera not in Landscape, Sport or No-Flash modes.
Low light conditions as determined by the camera - the 40D will AF without assistance down to very dim light conditions.
There can be problems due to dirty contacts on the flash foot or camera shoe.
My 550EX works fine with the 50D, so there should be a solution. Your camera makes full use of the 550EX feature set, and you should be able to see its Custom Functions on your camera's Flash Control menu.

[FireRob]

The 550EX should work fine with the 40D!
It's C.Fn 3 should be on 0.
AF in One-shot mode.
Camera not in Landscape, Sport or No-Flash modes.
Low light conditions as determined by the camera - the 40D will AF without assistance down to very dim light conditions.
There can be problems due to dirty contacts on the flash foot or camera shoe.
My 550EX works fine with the 50D, so there should be a solution. Your camera makes full use of the 550EX feature set, and you should be able to see its Custom Functions on your camera's Flash Control menu.

Thank you for the reply. Even after pouring over the manuals and this forum I failed to notice that I needed to be in "One Shot" mode. That did the trick.

You say that I should be able to see my flashes Custom Functions in the Flash Control menu. When I go the External Flash C. Fn setting menu the flash control menu I get a message that says "This menu cannot be displayed. Incompatible flash or flash's power is turned off." Also in the External flash func. setting menu All the options are grayed out except Flash exp. comp and E-TTL II. This was where I was trying to set the Shutter sync. to the second curtain but I found on this forum that you had to do that in the flash unles you have a 580EX II.

Can you tell me if you have access to these functions with the 50D? If so I wonder if Canon will ever enable these features for the 40D.

Thanks again!
-Rob

[CliveyBoy]

Oops, sorry Rob. The 550EX is too early for that feature. I do not know if the 580EX can be read by the camera, but the 580EXii sure can, and it's great!