Family Portraits Event

[littlevoice]

I am going to be taking portraits of families immediately after an event around 1 in the afternoon in open shade. These portraits will be posed for Holiday cards. I would love for some practical advice... lighting, preferred lens and Manual setting preference. I'm shooting with the Rebel xti
Here are the lenses I have to choose from:
EF 70-300 f/4.0
EF 28-135 f/4.0
EFS 18-55 f/3.5
Tamron 28-75 F2.8
Nifty 50 1.8

I can use any help/insight you have to offer. Thank you!

[EL Photo]

Hmmmm... Settings will depend largely on surroundings & light so I think that is pretty tough to answer over a forum board. It is also preference as well depending on "artistic vision" of the photographer. If your background is simple then you can get away with higher f/stops. However if you have trees or other distracting elements you will want to use lower f/stops for a more shallow depth of field. With what lenses you have I would use the Tamron 28-75, and or the 50 1.8 and wouldnt touch another lens. You may however find some use for the 70-300 at f4 to blur backgrounds, but you will be a ways away from the families depending on how large they are.

Hope this helps... Good Luck!