XTI mode confusion

I have a question I feel a bit silly for asking considering I've been shooting in full manual mode in my home studio for about a year, with no real problems.

I'm shooting an indoor event, my first, and will be putting my 580exII with Lumiquest Pocketbounce attached and mounting this on an ETTL cable on a flash bracket on my XTI.

I'm doing some test shots with this rig in my home prior.

Noise is a problem on the XTI for me, so I have ISO400 and auto white balance, with a center auto focus point.

When I shoot in P (or even full auto, but I want RAW, so I don't plan on using it) mode, just to gauge things, it sets to f4 and 1/60th

When I shoot in AV mode at f4, the shutter switches to something like 1/6th, or even slower.

Why is this happening? I have rarely, if ever, shot in P, so I've never noticed.

When in Av the camera meters for ambient light, even with the flash attached and turned on.

Av mode with flash is shutter dragging though on some models you can tell it not to go below 1/60th or 1/200th, 1/250th. Really if you don't want this shutter dragging, however, you should use manual mode with your flash. If you lock Av down so it can't drag the shutter then it is pointless to use it.

in auto the camera wont set a shutter speed slower than 1/60th to help avoid camera shake...if you take a picture you will see the background is underexposed while the subject is properly exposed/over exposed...

oldvultureface wrote in post #9492985
When in Av the camera meters for ambient light, even with the flash attached and turned on.

That would explain it - thank you.

I'm going to assume my best option is to meter in P, then switch to full manual?

bdpaco wrote in post #9493027
in auto the camera wont set a shutter speed slower than 1/60th to help avoid camera shake...if you take a picture you will see the background is underexposed while the subject is properly exposed/over exposed...

I rarely shoot in anything but AV or M, so I hadn't noticed this - thanks!

pcj wrote in post #9493036
I'm going to assume my best option is to meter in P, then switch to full manual?

What I do indoors with ETTL flash is meter in manual mode and set the shutter speed a stop faster than indicated. If the camera recommends 1/30 for proper exposure I'll set 1/60. This allows some ambient light to show in the photo but the flash provides most of the light for the subject(s). With your LumiQuest and a reflective ceiling that should provide a pleasing exposure.

oldvultureface wrote in post #9493124
What I do indoors with ETTL flash is meter in manual mode and set the shutter speed a stop faster than indicated. If the camera recommends 1/30 for proper exposure I'll set 1/60. This allows some ambient light to show in the photo but the flash provides most of the light for the subject(s). With your LumiQuest and a reflective ceiling that should provide a pleasing exposure.

Thanks, I just tried that method and it ended up being the exact same as shooting in AV mode - I'll chimp the exposure in manual on the day, I think, and see how it goes.

When shooting with flash always use manual mode.. Adjust your aperture and shutter speed to match the subject and available light..

yogestee wrote in post #9496963
When shooting with flash always use manual mode.. Adjust your aperture and shutter speed to match the subject and available light..

I'm at work without my camera - but wouldn't the flash just over expose the scene if I metered for ambient?

pcj wrote in post #9497290
I'm at work without my camera - but wouldn't the flash just over expose the scene if I metered for ambient?

Possibly my reply was over simplified..

If you are shooting indoor events the flash will govern the exposure.. This is the case unless you use a very slow shutter speed so the ambient light is registered with the combination of a large aperture..

This all depends on the brightness of the available light but with shutter speeds of 1/30th or faster, overexposure of the subject won't be a problem..

If for example you are shooting outdoors in sunlight, meter for the subject and adjust your flash so it underexposes by around 1 1/2 to 2 stops.. This is call fill flash and is a different topic..

Um, so I don't need to worry about this so much anymore - I just got home to a very early birthday present from my wonderful, supportive wife.

A nice shiny Canon 7D!

So I guess I need to figure this out before the shoot tomorrow afternoon! I have 3 shoots booked this weekend, and now I have a new toy too!

If you get back to the flash thing from enjoying your new 7D (enjoy ), read everything this guy has posted - it's great stuff for using flash:
http://www.planetneil.​com …h-photography-techniques/

stsva wrote in post #9501030
If you get back to the flash thing from enjoying your new 7D (enjoy ), read everything this guy has posted - it's great stuff for using flash:
http://www.planetneil.​com …h-photography-techniques/

Bookmarked, thanks!