Background Colouring using Gels

[inView]

Have a photoshoot soon with a dance troop doing portraits. Was gonna set up a white paper back drop and use a gel to colour it. Then use my 60" brolly as the main light on the subject.
Now problem time, I know that I cannot control the spill on my Brolly so I will need a large separation between the subject and the background, but can I colour the backdrop using a single gelled speedlight and keep a consistent colour and not have spill from my brolly?
I had tried this and seemed to have inconsistent light across the background ( a wall in this case as seen here)

Unfortunately I will have literally 3 or 4 frames with each person as time is v limited and I have very little time to set up so trying to prep before I got to the shoot. Anyone have any Views ?

 

[Garry Edwards]

A white background is a poor choice, unless you want the colour to be pastel - grey will give you the option of a more saturated colour, and if you had powerful studio flash then black would give you the ultimate choice.

I'm assuming from your question that you want a uniform colour - if so, then your better choice would be a coloured background but it can be done with a single speedlight and a gel, simply by lighting it evenly. I suggest that you use a reflective umbrella facing square on the the background and placed immediately behind the subject.

 

[ranarama]

I think you'd be surprised what a bit of black cloth used as a gobo on one side of an umbrella would make for reducing spill.

I don't think white is a bad choice necessarily but you need to reduce spill from the main light and a lower power on the background light will give a more intense colour.

 

[inView]

Thanx for the input, ironically had thought about using a reflective brolly to light the backdrop just after posting but never considered the actual colour of the paper so thanks for that.
Will try using the convertible section of the brolly as a gobo to prevent spill.

 

[snappingsam]

use a grey or black cloth - then light it with more power. That way the white spill won't show as much - but you will need a lot of power on the background light.

 

[riddell]

If you want the colour to be absoluetly even then you are much better off using a coloured background.

Usually gels are used to obtain these fall off effects.

Spill is easily controlled with flags.

Otherwise if you want it more even use multiple lights

 

[HoppyUK]

Good advice above. I'm guessing that you maybe want to gel it so you can change the colour easily? If not, a coloured paper background will surely be easier. Half width rolls (4' 6") are quite cheap.

Here's a good example of changing the background colour with a gel - this one has gone from blue to red! http://www.talkphotography.co.uk/forums/showthread.php?t=217214