What modifier would I need?

I have the two speedlights and an ocf cable.

I want to do an environmental portrait of a person, full body standing next to a racing kart on the starting line of the race track with a full background. I only want to light the kart and the driver and expose properly for ambient somewhere around the golden hours....

This is the kind of kart and driver I am talking about.
Kart Racing
I would shoot around steering wheel height with either my 50 or 100 or even the 24-70 at 35mm.....not sure yet and capture a full background/sky.

I don't know if I explained well, any ideas? Big softbox?

can you link to the particular picture, right now link goes to smugmug gallery.

you should be able to use Qbox24", umbrella, softliter, even bare flash etc, all depends on the look you looking for.

bobbyz wrote in post #13714548
can you link to the particular picture, right now link goes to smugmug gallery.

you should be able to use Qbox24", umbrella, softliter, even bare flash etc, all depends on the look you looking for.

well, none of the pics on my site are what I am talking about. i just wanted to show the kart to give a general size of the subject. i'll try to find a pic on POTN....

Like this but with a kart and person rather than the car.....

Like this

Looks like he just used a 580 and that's it?