Overhead shot of dancers' hard shadows - 1.8HMI?

[Josh Dunleavy]

This shot will be from directly overhead, with the dancer herself in the bottom 1/3 of the frame, and the shadow taking up the top 2/3 of the frame.

 

So, I obviously need a strong/bright, hard source that creates a nice sharp shadow.

 

The floor will be WHITE and approx. 15'x30', so this source needs to be able to fill up this entire space from a ~15 foot distance, and create/expose for pure white at 640 ISO, 1/240 sec exposure, f/1.4-f/2.

 

Will an Arri 1.8 HMI with a wide lens suffice? Is there any other unit I should consider that can run off house power, is very bright with a WIDE spread, and is less than 30lbs? The light will be mounted onto a jib/dolly combo so it can move up and down, left and right.

[Leonardo Brocato]

i think white floor it's a little bit overexposed ever!!!

m18 will be more than you need if i had understand settings

anyway arri site gives you all photometric datas you need here http://www.arri.com/lighting/lighting_emea/photometric_calculator.html#

 

m18 does not have lenses, you have the flood spot knot and changes really the beam,in my experience it's better not full flood because the reflector on the edge casts strange reflections
1.2k sun par will be cheaper and less power, at 15foot with flood lens throw 377foot candles and a beam of 19x12,at 500 iso (arri use 500 and 800 iso) at 1/192 (45°) more than f5.6++
Many posts here says that m18 for a house power it's border line in the Us due to the ampere differences between 110v and 220v of the european system so i suggest the dear old sun par 1.2k.
L7c led it's not enough at 15foot.

Leonardo Brocato
Gaffer Rome Italy