Hi everyone!

I am always asking question, and his time I need help..
How can I take a good picture of my grand daughter blowing bubbles?

Visit my Nikonians gallery.

Your question seems a little vague, but....

Depending on her size, sit or kneel so that you are down at her level.

The direction of the sun will have a color effect on the bubbles. I would start with the sun coming through the bubble from the back toward you.

---------+---------+---------+---------+
Joseph K
Seattle, WA, USA

D700, D200, D70S, 24-70mm f/2.8, VR 70-200mm f/2.8 II, 50mm f/1.4 D,
17-55mm f/2.8 DX, 70-300mm f/4.5-5.6 VR, 18-70mm f/3.5-4.5 DX

I'm more concerned about the bubbles I want to be able to capture them floating in the air...

Visit my Nikonians gallery.

You may need to use manual focus if the bubbles are your focus target. Just a guess as I have not tried this, but there is not much there to focus on.

Instead, I would place the child in profile such that the bubbles were blown across the frame so that they are in the same plane as the child, and focus on the child. As you move away from profiles, a smaller aperture will get you a bigger depth of field to include the child and the bubbles, assuming you want the child in focus.

---------+---------+---------+---------+
Joseph K
Seattle, WA, USA

D700, D200, D70S, 24-70mm f/2.8, VR 70-200mm f/2.8 II, 50mm f/1.4 D,
17-55mm f/2.8 DX, 70-300mm f/4.5-5.6 VR, 18-70mm f/3.5-4.5 DX

What would be the best camera postion in terms of aperture, iso, etc...

Visit my Nikonians gallery.

That will depend on your artistic desires.

Personally I would start with f/5.6 and adjust from there to get the depth of field I wanted (probably more shallow).

I would start with 1/125 (or higher) to freeze most of the child's motion, assuming she is relatively stationary. Adjust as needed to get the bubble effects you are looking for.

Lastly, I would adjust the ISO to whatever level was needed to make the above settings work.

Don't be afraid to experiment. Digital film is cheap.

---------+---------+---------+---------+
Joseph K
Seattle, WA, USA

D700, D200, D70S, 24-70mm f/2.8, VR 70-200mm f/2.8 II, 50mm f/1.4 D,
17-55mm f/2.8 DX, 70-300mm f/4.5-5.6 VR, 18-70mm f/3.5-4.5 DX