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Photography Question 
Teri F. Inman

Advice on chromakey backdrops

Hello, I`ve been interested in purchasing a green chromacolor backdrop and was wondering if they work like they advertise. I really like adding different digital backdrops but find it is very time consuming cutting out the person .Am I correct in assuming that you only need to use the magic wand to select the background in order to remove the subject? Any advice would be greatly appreciated as I don`t want to spend the money if they don`t really work. Thanks a bunch....

Teri in Canada

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8/23/2005 6:36:25 AM

Craig m. Zacarelli
BetterPhoto Member Since: 2/3/2005
  why not just use a white sheet or neutral colored sheet? I use a white sheet of paper and then extract by usint the square marquee tool... I do the pic in two halves... the top half then the bottom... I select the whole top half from side to side top to about halfway throught the subject, then I use the magic eraser to get rid of the background. then I do the bottom half the same way.. but I over lap onto the top half so theres no line running through the center of the pic. Then if there is any remnents left I just use the background eraser or regular eraser tool. Works like a charm.

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8/23/2005 9:57:38 AM

Teri F. Inman   Thanks Craig for your input. I have used a while sheet, also various other colors but seem to have trouble with consistent color. I have been doing the method you suggested BUT find it VERY time consuming and was looking for a quicker way. Guess I will just resign myself to the time......

thanks again
Teri in Canada

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8/24/2005 3:28:03 AM

Craig m. Zacarelli
BetterPhoto Member Since: 2/3/2005
  i have never used a chromakey so I dont know if it matters much. I dont see how it can be any different though. just get a few different colors... bright colors, so you can use what ever is more opposite than your subjects.

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8/24/2005 9:18:08 AM

Christopher A. Vedros
BetterPhoto Member Since: 3/14/2005
  Using a chromakey background makes it easier to switch out digital backgrounds because the color of the chromakey background is usually not found in any normal scene.

If you take a picture with the chromakey background, then you can select everything in the image that matches that color. In my editor, I use the magic wand, and uncheck the box in the dialog for "continuous area". This will select any area in the image that matches the color I click on, even little patches peeking through a person's hair or branches of a tree.

You could do the same with a white sheet, as long as there are no white objects in your image, which is unlikely.

It's more unlikely that anything in your image will match the color of the chromakey, unless Uncle Fred comes over in his bright green leisure suit again! ;-)

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8/24/2005 9:40:59 AM

Lauren Parker   Chris...
When I go to edit my photos I seem to have a green reflective edge around my subject. Do you ever get this? Do you light the backdrop or not? I think my light is spilling over to my subject, but they are far away from the backdrop and backdrop light. I am using a green chromakey. Any suggestions would be wonderful!

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3/3/2006 8:24:51 AM

Bret Tate
BetterPhoto Member Since: 11/12/2005
  Teri - Chris' response is correct. The Blue & Green Chromakeys are used to not match most other colors. You want a consistent color so you can set the tolerance to a very low value, 1 or 2, on the magic wand and get all of the background selected. The problems with using a white sheet are consistent color and it could match other colors in the photo.

Lauren - When using chromakeys it is important to get even light throughout the background. This is usually done by using two background lights set up for copy lighting. However, you need to be careful with the intensity of the light. If the background becomes too bright compared to you subject lighting you will experience some "wrap around" of the background. In any case, you will almost always need to do some clean-up of of some of the edges.

In our photo business we use chromakeys for magazine cover photos, some of our nostalgia photos, & school photos(this allows the client to pick a background from selections that include outdoor scenes).

I hope that this helps.

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3/3/2006 9:28:47 AM

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