Color Gel Filters

[walkien]

I just bought some color gel filters today, and did some test shots with 1 light point to a white paper backdrop(about 2 feet apart),1 light point to a subject, the distance of both lights is about 7 feet apart, but I don't know what I did wrong, the back drop did not show any color at all, I've try different settings (1/16,1/8,1/2 power....etc), I'll post some sample later when I get home.

[tim]

So one piece of paper is white (with flash/natural/tungsten lighting) and one is white paper gelled... what color gel? I'd try a custom white ballance on the white paper.

[walkien]

let me rephrase the question again, 1 strobe light pointed to a white backdrop with a blue color gel filter on (background light?), and 1 strobe light pointed to a subject with no color gel filter(main light). What I want to achieve is a blue background effect.

[walkien]

This is the effect I want to get.
http://photography-on-the.net/forum/showthread.php?t=133322

[LightingMan]

Dear Walkien
Your question about using gels and not getting the deep saturated color that you desire is an extremely common one. I don’t think a week goes by without several questions on this topic coming my way.

Using gels is actually very simple once you understand the concept here. I looked at the image you are trying to emulate. The photographer used a white background which is quite unusual when you are wanting a deep saturated color. The reason he succeeded was because he was very careful in how he lit the subject. He directed light ONLY to the model’s face and of course the hair light was never facing toward the background so it was a none issue. I saw no evidence of a fill light so there was no light reaching the background from a fill source. In the absence of light, even white paper will appear black. In his case, the gelled light was the only source of light reaching the seamless.

The reason photographers get pastel colors or even white when they are wanting deep colors is mostly because the are using white seamless instead of black. Stop and think what will happen when your main light spills light onto a white background. It will go some shade between gray and whited depending on how much light reaches is relative to how much light reaches the face. Blue light on white paper that is already getting white light from another source will always be pastel or baby blue. It’s like mixing paint. Blue paint plus white paint gives you some shade of pastel blue. If all you want is solid blue, then you had better not get anything othing other than blue light onto the background. With white paper it takes very little light to make it look light.

You also didn’t say how much light you are allowing to reach the background so that is probably a problem as well. You are most likely over lighting it IN ADDITION to using white seamless. Photographers tend to over light the background in an effort to (their words)”blow out the background”. What is actually needing to be done is to illuminate the background so that it receives 1 and 1 1/3 stops more light than the subject receives. If the taking aperture is f*8, then a reading at the white seamless facing the lights needs to be f 11 and a third. No more. Over lighting the white seamless will produce a reduction in contrast and color saturation. Your large white background that is over lit is actually causing lens flare. In this case, it manaifests itself as a mudding looking image frequently with the edges of the subject blending right into the white background.

When you are using gels for a saturated color effect, It’s very difficult to use white seamless and not have at least some white light from the other lights reach it. If you use any kind of fill as you most likely need to, that fill will also be putting white light onto that white paper.

If you desire deep saturated colors, you must begin with a dark background and then work toward not allowing white light to reach it. If you can light your subject so that virtually no light reaches the background, you will have a suitable canvas for painting with deep saturated colors but even with a dark background, if you contaminate it with white light, you can forget getting the saturated color you desire.

Using gels has been a very large part of my photography for 25 years. I couldn’t imagine not having color gels to use in my images. Below are two of my images that show the deep, saturated color on a black seamless background. I hope this helps you solve your problem. Feel free to contact me if you are still having difficulty. Happy to help.
Best wishes,

[walkien]

Scott,

Thank you very much for the info, I'll try again sometime this weekend.

[nimzo]

I'm doing fine getting the deep color, but I am also getting a color ring outlining my subject. How do I get rid of that?

[rabidcow]

I'm doing fine getting the deep color, but I am also getting a color ring outlining my subject. How do I get rid of that?

usually this is caused by a background overexposure. Meter your background light (to the background) no more than one stop over your meter reading for the subject.

[nimzo]

usually this is caused by a background overexposure. Meter your background light (to the background) no more than one stop over your meter reading for the subject.

Thanks for your suggestions, but no matter how far I turned down the background light, I continued to have the same problem. However, I was using a white seamless paper background, and after reading your prior post, I switched to black. Not only did this solve the problem, but the background color, as you suggested, was much richer. I think that light was reflecting back from the white background and creating this glow around the subject. I would, however, like to retain the flexibility use the white background, particularly where I want more pastel background colors. Any additonal thoughts on solving this problem?

[rabidcow]

Try metering the the backgound light with gel to 2.8 or less (assuming that you are shooting at f/8-f/11) this might work for you. My white sweep at the studio requires about f/2 in order to obtain good color, anything more causes a white hot spot that halos out to original color. I do not shoot on seamless all that much, but I would imagine that it is pretty close to my painted sweep.

[Inspired Photography]

Nimzo, you probably need to put more distance between your subject and background to stop those reflections.

Rob

[LuisE]

Dear Walkien
Your question about using gels and not getting the deep saturated color that you desire is an extremely common one. I don’t think a week goes by without several questions on this topic coming my way.

Using gels is actually very simple once you understand the concept here. I looked at the image you are trying to emulate. The photographer used a white background which is quite unusual when you are wanting a deep saturated color. The reason he succeeded was because he was very careful in how he lit the subject. He directed light ONLY to the model’s face and of course the hair light was never facing toward the background so it was a none issue. I saw no evidence of a fill light so there was no light reaching the background from a fill source. In the absence of light, even white paper will appear black. In his case, the gelled light was the only source of light reaching the seamless.

The reason photographers get pastel colors or even white when they are wanting deep colors is mostly because the are using white seamless instead of black. Stop and think what will happen when your main light spills light onto a white background. It will go some shade between gray and whited depending on how much light reaches is relative to how much light reaches the face. Blue light on white paper that is already getting white light from another source will always be pastel or baby blue. It’s like mixing paint. Blue paint plus white paint gives you some shade of pastel blue. If all you want is solid blue, then you had better not get anything othing other than blue light onto the background. With white paper it takes very little light to make it look light.

You also didn’t say how much light you are allowing to reach the background so that is probably a problem as well. You are most likely over lighting it IN ADDITION to using white seamless. Photographers tend to over light the background in an effort to (their words)”blow out the background”. What is actually needing to be done is to illuminate the background so that it receives 1 and 1 1/3 stops more light than the subject receives. If the taking aperture is f*8, then a reading at the white seamless facing the lights needs to be f 11 and a third. No more. Over lighting the white seamless will produce a reduction in contrast and color saturation. Your large white background that is over lit is actually causing lens flare. In this case, it manaifests itself as a mudding looking image frequently with the edges of the subject blending right into the white background.

When you are using gels for a saturated color effect, It’s very difficult to use white seamless and not have at least some white light from the other lights reach it. If you use any kind of fill as you most likely need to, that fill will also be putting white light onto that white paper.

If you desire deep saturated colors, you must begin with a dark background and then work toward not allowing white light to reach it. If you can light your subject so that virtually no light reaches the background, you will have a suitable canvas for painting with deep saturated colors but even with a dark background, if you contaminate it with white light, you can forget getting the saturated color you desire.

Using gels has been a very large part of my photography for 25 years. I couldn’t imagine not having color gels to use in my images. Below are two of my images that show the deep, saturated color on a black seamless background. I hope this helps you solve your problem. Feel free to contact me if you are still having difficulty. Happy to help.
Best wishes,

Dear lightingman,

Your explanation is really amazing. I was trying to use gels some days ago with no success.
Thanks for this valuable info.

LuisE

[coreypolis]

Here is part of an assignment I did for school. the idea is to match clothing to a background, so in order to do this we had to test various gels. I started with the lens that had the largest aperature range tht I had (135L had 9 stops), put the gel over the light, metered it until it said f/8 (in the middle of the range), and then shot from f/2 to 32, and you can see how exposure changes the intensity

http://img.photobucket.com/albums/v721/viperx27/IMG_2193.jpg



and here was the final image


http://img.photobucket.com/albums/v721/viperx27/Brooks/IG3Q56791.jpg



this was done with a white seamless, 2 strobes with umbrellas

[TSP2010]

Just a little something I have learned. The darker the paper, the richer the color is. I use a dark brown paper with my gels and the colors are amazing!





I just bought some color gel filters today, and did some test shots with 1 light point to a white paper backdrop(about 2 feet apart),1 light point to a subject, the distance of both lights is about 7 feet apart, but I don't know what I did wrong, the back drop did not show any color at all, I've try different settings (1/16,1/8,1/2 power....etc), I'll post some sample later when I get home.

[pcj]

When you have a home studio, with limited space - how do you prevent light from hitting the backdrop?

I'm still experimenting, but my model stands maybe 6' in front of the backdrop, I turn my genesis lights down to 20/25, and fire my 580 ex II with gel at 1/2 (full seems to blow through the gel).

I have umbrella's on the genesis lights, but do have a set of barn doors and a grid on order (should be here today) - I've had a little success, but not brilliant.

See here (http://www.flickr.com/photos/paulandbeth/4228909822/) and here (http://www.flickr.com/photos/paulandbeth/4217020745/) for what I consider my best efforts yet.

[TSP2010]

Explain it a little what do you mean by keeping the light from hitting the backdrop?