ETTL II, "P", & Aperture

wolfejm

Hi Gang,

This is probably a silly question. I have a Canon XTi, a 430EX and recently upgraded to a 24-105L :wink. I take a lot of family photography in addition to my semi-serious hobby work. For the family shots, I'd really like to be able to use P mode on indoor shots. Here's what I've noticed since upgrading to the L lens. In P mode, the camera seems to select the widest aperture the lens supports. This wasn't a problem before I upgraded lenses, but now it always selects F4 which can provide too shallow depth of field for family shots.

Since I want the flash to be the primary light source for these shots, I'd like to be able to use P mode. Is there anyway to use P mode with the flash and change the f-stop? Seems like the ETTL II metering ought to be able to compensate for whatever the actual settings are at shot-time, but I can't seem to figure it out. :dunno

Thanks,
Jeff

Cuong

You cannot change aperture or shutter speed in P mode using flash. Your best bet is switch to manual mode (M) and set your desired aperture and set the shutter speed to your flash sync speed. ETTL will take care of flash exposure for you. For more reading on this subject, check out Pathfinder's posts http://www.dgrin.com/showpost.php?p=665711&postcount=3.

Cuong

pathfinder

This one will help also - http://www.dgrin.com/showthread.php?t=70330&highlight=fill+flash+pathfinder

For family candids, I like off camera ETTL flash as I wrote about here - http://www.dgrin.com/showthread.php?t=49999

Using Av, Tv and Manual gives you much more control and finesse than P, or Auto too

wolfejm

Cool!
Thanks for the great suggestions. Honestly, I hadn't really considered manual mode because I figured it would be too much hassle. I think I understand it much better now, especially that I realized even in manual mode, the flash is essentially auto exposing the foreground.

I also like the thought of off-camera flash essentially preconfigured for the room. Just one question. I have a 430EX, and can't really afford or justify the 580. Can I use the ST-E2 and one 430EX? I'm very excited about this idea.

Pathfinder, that diffuser, was it a foam brick or a foam card strapped to your flash? That part wasn't clear to me and your self portrait (I think) shows a difuser block over the flash. I just want to make sure I understood what sounded like a cool setup.

Thanks again!

pathfinder

The picture of my brother was with a 1DMkll with a Stofen on his flash.

But I used a foamie diffuser - a sheet of 1mm thick white foam that is used like a 3x5 card taped to the back of your strobe - I pointed my strobe at the ceiling ( which was white fortunately) and used the foamie to throw some light forward as well. I shot in Manual mode on the camera with the ST-E2 to trigger a EOS speedlite in ETTL mode. This trick will work with the 430ex or the 580ex, or even a 550ex.

I gave a link in that thread to another thread about the foamie diffuser. If you can't find that thread, let me know, and I'll see if I can dig it up this week end. I'll bet it pops up on a google search also. There was a nice video on YouTube about foamie flash diffusers also. The foamie diffuser is really cheap, easy and worthwhile. I leave mine on my speedlites, folded back, so they are always there when I need a little sparkle in the eyes.

wolfejm

pathfinder,
Ok, I found the thread on the diffusers and several youtube videos. I have gotten a ton out of this thread. I appreciate all the help.

For posterity in the search index, the foamies diffusers are also described at http://www.abetterbouncecard.com.

Thanks!

pathfinder

That's it!!