John,
the advantage of modeling lights is that they close down the pupil so that more of the iris shows in the eyes. The dimmer the ambient light, the wider the pupil when the strobes go off and the greater the chance of red-eye. Try it both ways and see what works with each individual dog. I've found that when the ambient light level is high enough, I really don't need the modeling lights to focus and the eyes look fine.

Good luck with the outdoor shots today. It's going to be a challenge because the weather calls for overcast and windy. The good news is that it will be cool. If the Chihuahua is a short hair, that may mean he/she will be shaking so take that into account.

Good thing you're not doing a group shot -- they can be a bear! My record is 7 Duck Tolling Retrievers in one shot. I had a full head of dark hair before that session. When you meet me you'll appreciate that comment.

Please share some of the shots from today.

Jim