Can I get a short exposure and adjust the aperture with external flash?

I'm trying to work on my goal of understanding flash lighting better, but for such a nuanced subject there is so little good information, either in the manual or in books that I've read. I would really appreciate any help you can give me.

I have a 30D with the Metz 58 AF-1 external flash. When I bought the camera in June the salesman raved about the Metz and since it was cheaper than the 580 EXII I trusted his judgement. Overall I've been pleased with it.

Let's say I'm in a relatively dim room with my EF-S 17-55 2.8 lens and the flash attached. From reading and experimenting I know I can set the camera to Av and I will get a long or longer exposure depending on what aperture I select; I can set the camera to Tv and I will get a short exposure with a 2.8 aperture; and I can set it to M and I will again get a long or longer exposure depending on what aperture I select.

But what if I want a short exposure (I have shaky hands and need a faster shutter speed for well focused pictures) and I want a greater depth of field than f2.8? It seems that with plenty of light from that flash a smaller aperture should be no problem but I haven't been able to figure this out. Is this possible? Or have I misunderstood something along the way (which is entirely possible since it seems like the only way to really understand flash is by trial and error, the manual and the books just give it the briefest mention).

Have you tried it?

Manual mode, 1/200 f/8 ISO 100

Flash in E-TTL mode, flash head pointed straight forward.

Take a picture.

If you don't like the exposure, adjust FEC and try again.

Kent Clark wrote in post #4719845
I'm trying to work on my goal of understanding flash lighting better, but for such a nuanced subject there is so little good information, either in the manual or in books that I've read. I would really appreciate any help you can give me.

I have a 30D with the Metz 58 AF-1 external flash. When I bought the camera in June the salesman raved about the Metz and since it was cheaper than the 580 EXII I trusted his judgement. Overall I've been pleased with it.

Let's say I'm in a relatively dim room with my EF-S 17-55 2.8 lens and the flash attached. From reading and experimenting I know I can set the camera to Av and I will get a long or longer exposure depending on what aperture I select; I can set the camera to Tv and I will get a short exposure with a 2.8 aperture; and I can set it to M and I will again get a long or longer exposure depending on what aperture I select.

But what if I want a short exposure (I have shaky hands and need a faster shutter speed for well focused pictures) and I want a greater depth of field than f2.8? It seems that with plenty of light from that flash a smaller aperture should be no problem but I haven't been able to figure this out. Is this possible? Or have I misunderstood something along the way (which is entirely possible since it seems like the only way to really understand flash is by trial and error, the manual and the books just give it the briefest mention).

In Manual mode, ignore the built-in meter (it's only metering the ambient light) and set the aperture and shutter speed to whatever you want.

As long as the meter blinks at the far left, the shutter speed doesn't matter. It can be 10 minutes long and the flash burst is so quick that you won't have a shaky photo.

In other words, shoot at the aperture you need, keep the shutter speed short enough to not let much ambient light in, and you're good to go. FEC is your friend.

All three of you have pinpointed my problem. In Manual mode I was being an obedient guy and adjusting the meter to zero, which of course gave me a long exposure in dim lighting. Thanks for the help. I'll try it tonight.

Now why can't a book or the manual dedicate a few lines to something so simple and straightforward that it took you guys only a few sentences to enlighten a dim flash like me?

Kent Clark wrote in post #4721797
Now why can't a book or the manual dedicate a few lines to something so simple and straightforward that it took you guys only a few sentences to enlighten a dim flash like me?

Good question. And one that no one knows the answer to.

Kent Clark wrote in post #4721797
Now why can't a book or the manual dedicate a few lines to something so simple and straightforward that it took you guys only a few sentences to enlighten a dim flash like me?

Kent,

There's some good info in the EOS Flash sticky thread. You may want to start here:
https://photography-on-the.net/forum/showthre​ad.php?t=171657

Curtis, just before you posted that link I noticed it in your signature. I've put it in my favorites and will be studying it. Thanks.