Exposure

[Wingerpaul]

Sorry if this has already been discussed.

I can't seem to get a good exposure when using my 420ex flash and studio lights together. Is there a custom setting that would tell the D20 to not underexpose just because it see's more light or what can I do? The only way I was to work around this with my 300D was to put a piece of tape over the 4 control pins on the shoe or use a generic flash to trigger the studio lights.:cry:

[Mike Panic]

do you by chance mean a 20d?
what studio lights are you using?
what exactly is the problem you are having, underexposure or over exposure?

could you post a problem pic and the exif data with it?

also - not many studio photographers that i am aware of are using an on camera flash to trigger their strobes.... you may want to look into an st-e2 transmitter from cannon

[scottbergerphoto]

The 420EX isn't designed to be used as a manual flash. If as I suspect you have the 420EX in the hot shoe and are adding some studio flashes, the pre flash from the 420EX is setting off the studio strobes which in turn shuts down the output of the 420EX. You can't combine ETTL and strobes. You need the hot shoe flash to be in Manual Mode (no pre flash) and use a flash meter to set your f stop.
Scott

[Wingerpaul]

How do I cet the Hot shot to Manual Mode?

[scottbergerphoto]

You have to set the flash to Manual Mode. The problem is the 420EX doesn't have one. You need a different hot shoe flash to do that, like a 550EX or 580EX.
Scott