Quick question about P mode

Never ever have used it (p mode or second curtain sync) until just 5 minutes ago. Had a 430exii flash attached in high speed burst mode. Iso set to 100. I think second shutter sync was enabled on the flash. When shooting in high speed burst, after 3 or so shots, the camera would just stop midway of the shutter opening and closing and the screen said busy. This does no happen in manual or tv mode. Camera in this circumstance is a T3i.

Usually that means it is writing to the card but you should be able to handle a burst of more than three shots. Try another card and see what happens.

Good Luck
Mike

I'm wondering if in p mode the camera is setting the shutter slower and slower as the flashes go off and hence a longer shutter time for the second curtain sync...

The buffer was crippled because of raw +l. Never realized how much that slowed it down, not really a high speed shooter most of the time. But with that being said, p is always playing with shutter during metering. So it slowed the shutter from 1/60 to 1/20 by the third exposure. Only thing I could figure is from camera metering the flashes.....

Flash is best done in Manual mode on the camera and ETTL-II engaged on the flash.

With flash, the flash capacitor needs to the filled with electricity because it is near empty...analogy you use an 8 oz cup to very rapidly throw water (HSS) but then the bucket is nearly empty so you have to let the bucket fill from the hose before you can resume throwing water with the 8 oz. cup again!

If the flash is recycling (filling the bucket from the hose) there is no light coming from the flash, so P mode says "I need to open the shutter long" because the ambient light is low and the shutter speed of 1/60 which is set when P mode is chosen (and flash is turned on) is too fast.

Thanks Wilt. That explains it perfectly. I always shoot manual with ettl. I for some reason was fooling around with P and noticed this for the first time. Thanks guys.