Weird problem with 40D and internal flash.

Hi,

I was using my 40D indoors yesterday (w/ Tamron 17-50) and noticed that in the creative zone modes, AV, P, and M my internal flash would not fire. Even though I had popped it up just like I always do.

In the Auto (green box) mode, it would fire like normal. But not in the creative mode. After some playing around with it, I switched from One Shot to AI Servo mode and it proceeded to work fine. Switched back to One Shot and it once again would not fire.

Is this normal? I was taking pics of stationary objects and for some reason, it just wouldn't work like it normally does even though it appeared to work for the last 4 months just fine while in One Shot mode.

It's a sign that you need to buy a speedlight

Seriously, a flash that allows you to bounce off of walls/surfaces, has WAY MORE power, and supports shutter speeds faster than 1/250s will make you wonder why you ever bothered with the pop-up flash.

I have a 430EX. Just bugs me trying to figure out this problem.

Don't let it bug you....Since you have a 430EX, why would you possibly want to use the pop-up flash? I think I used the pop-up flash ONCE on one of my Canon bodies, and the picture was quite awful looking.

Well I am thinking that if my camera isn't transmitting data correctly for the on board flash to work, is it transmitting data correctly enough for my 430EX to work? That is my concern.

I guess that's possible, but have you experienced any problems with the 430 firing/not firing? You were shooting Green box just to test the flash, right? You'd never actually use the Green Box mode for any real pictures?

Just bustin' your chops a little, I try to "wean" folks off of the pop-up flash as early as possible, glad you're using a speedlight

Check the flash setup menu screen. Most probably you've disabled the flash, but that's not possible to do in any of the "idiot modes".

Oops, I now noticed that it works in Servo AF but not in One Shot AF. Usually if there's no flash in One Shot AF it's because there's no picture either, which in turn is because it was too dark to focus, but I assume you do get pictures, albeit dark ones, right?

apersson850 wrote in post #7950558
Usually if there's no flash in One Shot AF it's because there's no picture either, which in turn is because it was too dark to focus, but I assume you do get pictures, albeit dark ones, right?

Not always, sometimes it will not even focus enough to let me take a pic.

Well, if it can't focus, there will be no image, hence no flash, of course.

Do you use AF assist?
If you set your camera to manual focus, does it then fire all the time?
You are also sure it fires every time when in Servo AF?