Forums > Photography Talk > Colored background using gel

Photographer

OLJ studio

Posts: 1550

Winnetka, California, US

I’m a little bit confused.
If I shoot against white wall and I’d like to use gel to get colored background
Should I set background light to the same F-stop as the key?

May 07 07 05:17 am Link

Photographer

Wolfdreamsphotography

Posts: 43

Sahuarita, Arizona, US

Quick answer, yes.  However, there are some things to consider, make sure you have enough distance fm model or you get bounce back color, also if you want to lighten the color you can up a stop or so,, etc.

May 07 07 05:36 am Link

Photographer

Sean Armenta

Posts: 1560

Los Angeles, California, US

LJO studio wrote:
I’m a little bit confused.
If I shoot against white wall and I’d like to use gel to get colored background
Should I set background light to the same F-stop as the key?

actually, it depends.

first off, gels show up easier on a gray background than a white background, as white will wash out the color and gray or even black will do a better job of holding the color.

depending on how intense or saturated you want the colors to be, you will have to underexpose instead of doing a 1:1 with your key.  overexpose and it will just go to white. 

blue, for example will need to be under by 1 or 2 stops.  i assume you are shooting digitally, which makes it much easier to figure out.  expose for your background first and shoot at different exposures to get the color you want.  then you can light for your subject (key), but be sure not to get any spill on the background as it will wash it out.

May 07 07 05:46 am Link

Photographer

Sean Brown Photography

Posts: 186

Dallas, Texas, US

It's not that simple, because saturation is a factor as is bleed from the main light.  The easiest approach for me has been to make the background exacly as I want it to appear in camera by stacking gels etc... and then add the model and the entire lighting system that the model will be lit with and very carefully control the light leakage between the two lighting zones.  This requires quite a bit of space usually so the colored background may need to be a bit bigger than you initially think especially if you shoot on a "normal" lens.  For head to toes gel is just not an option and colored paper is much easier.  In fact, colored paper is almost as cost effective as gel is and makes life much simpler.

May 07 07 06:14 am Link

Photographer

Clint Jeffries

Posts: 9

Helena, Montana, US

Grey background paper.  Used two different colors on the background.  I am sure there are those who could rip it to shreds.  But it does some redeeming qualities.  I kinda like it.  big_smile

https://www.modelmayhem.com/pic.php?pid=2661175

Other examples of grey background and colored gels here.

http://viewmorepics.myspace.com/Modules … &albumId=0
My suggestion however, go with the Savage brand.  I have both black and white by Savage and in my experience that is a much more durable product.  The grey I have is another brand which tears much more easily.  It requires more careful handling.

May 07 07 06:33 am Link

Photographer

Warren Leimbach

Posts: 3223

Tampa, Florida, US

LJO studio wrote:
I’m a little bit confused.
If I shoot against white wall and I’d like to use gel to get colored background
Should I set background light to the same F-stop as the key?

Gelled light meters differently than white light.  (That used to mean shooting a lot of polaroids to get make sure the gelled light really did what you expected.  Now with digital you can see your results much quickly and cheaply.)

Red light in particular is difficult to meter.  Usually underexposed 3 stops from the meter's recommendation.

For deep rich colors, shoot gelled light onto colored paper - blue light onto blue paper, etc.

Gelled light on grey or black background works well too.  Black takes a lot more power of course but it is less likely to wash out if the main lights spill on it.

Since you are shooting against white, I would meter the background at 1 stop below your shooting aperture.  Ex: meter lights at f /5.6   cameras aperture set at f /8



Good luck,


WCL

May 07 07 06:43 am Link

Photographer

Analog Nomad

Posts: 4097

Pattaya, Central, Thailand

You'll have a very hard time getting intense color from gelled lights against a white background. Much easier with black:

https://bangbangphoto.com/v-web/gallery/albums/Johanna/59AF0589.jpg

https://bangbangphoto.com/v-web/gallery/albums/Johanna/59AF1244.jpg

https://bangbangphoto.com/v-web/gallery/albums/Natalie_Studio/59AF7573.jpg

https://bangbangphoto.com/v-web/gallery/albums/Natalie_Studio/59AF7667.jpg

Just bring the lights up and chimp while varying intensities until it looks good.

May 07 07 06:48 am Link

Photographer

ChrisPaul- Chrispimages

Posts: 512

Los Angeles, California, US

Sean Armenta wrote:

actually, it depends.

first off, gels show up easier on a gray background than a white background, as white will wash out the color and gray or even black will do a better job of holding the color.

depending on how intense or saturated you want the colors to be, you will have to underexpose instead of doing a 1:1 with your key.  overexpose and it will just go to white. 

blue, for example will need to be under by 1 or 2 stops.  i assume you are shooting digitally, which makes it much easier to figure out.  expose for your background first and shoot at different exposures to get the color you want.  then you can light for your subject (key), but be sure not to get any spill on the background as it will wash it out.

YEAH! what he said!

May 07 07 06:55 am Link

Photographer

R Michael Walker

Posts: 11987

Costa Mesa, California, US

I too use black for most of my gelling. I have 3 colors of paper rolls hung in sequence above my shooting area. Black, white and green. I used to use Grey but it's to easy to get that color from the white or black rolls.

May 07 07 07:01 am Link

Photographer

OLJ studio

Posts: 1550

Winnetka, California, US

bang bang photo wrote:
You'll have a very hard time getting intense color from gelled lights against a white background. Much easier with black:


Just bring the lights up and chimp while varying intensities until it looks good.

What distance do you keep from background?
Do you flag background light from the subject?

May 07 07 10:17 am Link

Photographer

Analog Nomad

Posts: 4097

Pattaya, Central, Thailand

I try to set the lights a couple feet from the background -- usually one on each side, sometimes with a different shade of gel on each side.

I always flag the background lights, but tend to feather the edge so that a little of the gelled light hits the subject -- or not. Depends on the effect I'm going for.

LJO studio wrote:

What distance do you keep from background?
Do you flag background light from the subject?

May 07 07 10:20 am Link

Photographer

ward

Posts: 6142

Toronto, Ontario, Canada

Gels work best on dark greys and blacks.

May 07 07 10:28 am Link

Photographer

David Weiss

Posts: 7130

Oshkosh, Wisconsin, US

Another way would be to light from behind against an RP screen.  In the experimental shots in my port, the screen was a piece of smoked plexi with one side sanded with 120 grit.  Lighting was done with hi-intensity LEDs.

May 07 07 10:47 am Link