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Green Screen Question???
Have never shot using green screen before, do i have to get from a special background dealer... or can i go to my local fabric store and get a bright green felt fabric to use?? tia Apr 24 16 05:26 am Link Ive bought store fabric that was bright and very saturated and it worked out fine. Just dont go into the reds or yellows or orange colors...the colors that skin is made up of. The green and blue colors have been optimized for TV and software extraction with people as the foreground. Make sure you have a way to stretch and hang your fabrics tightly to smooth out those pesky wrinkles that dont key well. Some photographers prefer Chroma Key seamless background paper or painted foam core panels. Dont get shiny or glossy fabrics...the shine sometimes doesnt cut out cleanly. Apr 24 16 06:00 am Link Local camera shop sells kits which essentially contains a green cloth backdrop and software. You can probably find same at B&H. What I wonder is how good it really works. I use a white backdrop and remove the background in Photoshop. That leaves a white edge around the object and I have to manually erase the edge which is tedious. I wonder if those kits leave an edge too. Apr 24 16 06:35 am Link There are paints made specifically for chroma key. A pure colour from your local paint store will work as well. A painted flat is much easier to use unless you have a way to stretch your fabric to a wrinkle free state. Apr 24 16 07:35 am Link i want to use it with this software..... http://www.owens-originals.com/green-sc … -p/gsw.htm Apr 24 16 07:46 am Link Shoreline Pictures wrote: ^This^ but whether you paint or use fabric, be sure that the material you use absorbs light as much as possible rather than reflecting it. I made the mistake of using a medium luster latex wall paint and had to be extra careful to pose the model away from the green screen to avoid having a greenish tint to the skin. Apr 24 16 08:07 am Link MirrorImage Photography wrote: JoAnn Fabrics sells a green color called Kelly Green that is a near perfect match for some of the Chroma Green colors sold by background roll paper companies. Apr 24 16 08:20 am Link I use royal blue seamless paper which seems to work great for me as a chroma key color as well as a color in general. Apr 24 16 08:34 am Link the software program has a built in feature, that you can just brush out the dark wrinkles... one easy step Apr 24 16 08:54 am Link I watched a two-day live event with a composite photographer on Creative Live last month who uses a gray paper for her green screen. She explained a lot of valid reasons for it, most of which I forget. She does show some before-and-afters here with the gray and the composites off it halfway down the page: http://petapixel.com/2015/09/15/renee-r … cle-crash/ She also shows it in her cool video on the same page too. Gray? But it works for her. Apr 24 16 09:40 am Link For professional photography and real composite work , forget any green/screen backgrounds or any chroma key software. Green/Blue Screen is for video composite work . Even in video composite work chroma key is just a basic step for extraction, for top results later you have to work rotoscoping very often frame by frame. For image composite work white/grey background is industry standard . Chroma key software with sliders and green/blue screen backgrounds is for quick amateurish results with tons of halo edges and problematic colors cast around, with some file maybe you can get some decent results with low res images but for serious results no. If you want to learn composite work - Photoshop only and white/grey backgrounds . You can also work in PS with green /blue screens but you have to now how to make decontamination of green color cast. Best Apr 24 16 10:22 am Link ST Retouch wrote: This. Apr 24 16 12:15 pm Link Apr 24 16 12:42 pm Link anchev wrote: Yes, fine for moving pictures. I don't understand how anyone would use green screen for stills, though. Apr 24 16 01:46 pm Link Kent Art Photography wrote: Moving pictures = sequence of still pictures. I don't understand how anyone would use green screen for stills, though. It depends on the purpose. Apr 24 16 02:39 pm Link anchev wrote: Anchev, thank you for link. Apr 24 16 03:26 pm Link ST Retouch wrote: Hi, Apr 25 16 01:26 am Link Kent Art Photography wrote: Green screen works fine if you have enough space so that there is no spill - if there is spill (which most here will face) it's a nightmare. If you have a good 12 feet or more between your subject and the background, and you light it properly, green screen is very easy to work with. Apr 25 16 07:31 am Link I've done some green screen. With proper technique one can reduce any green fringing to a point it won't be noticeable even if superimposed on a white background. Minor blue fringing is much less noticeable against most new backgrounds than green is, so consider using that instead. The problem is blue clothing is much more common than green. You'll also have to mask a model's eyes if they are blue, or you see the background through her eyes which is kind of creepy. I would agree that learning to extract from a white background in photoshop is probably a good skill t have, but having an instant software extraction has it's place. Apr 25 16 07:58 am Link Giacomo Cirrincioni wrote: You can kill green spill by using a magenta filter on a light that shines on the model's hair and shoulders Apr 25 16 09:12 am Link Light and Lens Studio wrote: In theory yes, the colors cancel each other. In practice in anything other than the most controlled still life, you'll wind up with magenta spill that then has to be dealt with. Personally, I'd rather deal with the green contamination in post. Apr 25 16 09:29 am Link Light and Lens Studio wrote: I don't really do compositing - but from purely a lighting perspective I would not want to deal with the headache of this approach with partially crossing casts. Apr 25 16 01:46 pm Link For the OP...the Color... or the Kind of material you use... is only part of the keying formula. Here are 6 general guidelines for Chroma Keying that most commercial studios will keep in mind when setting up for a shoot. Apologies for the length. 1. The Color. Use the highly saturated and bright industry standard Chroma Key Green or Blue for the easiest way to get good results quickly. People in the industry have spent years fine tuning those special colors. If you have a robust keying program... then you could also possibly use a Light Battleship Gray color as the keying color in the studio. I use the $89 Fluid Mask program and a gray screen in my studio to get single hair strand precision much of the time. Fluid Mask is able to cut with ANY color... as long as the background is not too overly complex. If you are just starting out... or are doing a commercial job...then the specific ChromaKey Blue and Green colors and values are highly recommended. 2. Even Background Lighting. Keep the background evenly lit from top to bottom and from left to right. Diffused broad softbox kind of light from both the left and right sides is fairly good. If you use fabric...make sure you can stretch it so you dont have any wrinkles that wont key out well. Love using seamless background paper because it is easy to hang smoothly and it takes light well. Painted flats work well too. The key to good Chroma Keying is to get your background evenly and broadly lit with no wrinkles or shadows behind your talent. 3. The Cutting Program. The program you use to cut with is very important for great results. Some of the free programs dont cut anything but green or blue. The inexpensive programs can sometimes cut other colors... and some of them allow you to repair shadows or other problems with the background. (Big Help). The more expensive programs can cut any color, they can mask out bad places in your background, they can clean up the masks real well after the fact, they have tools to reduce spill or contamination, they have the ability to optimize the mask in many ways, and they are able to resolve even single wisps of hair accurately... if... the edges of your hair are against a smooth background, with a strong contrasting color, that is properly lit, with no complexity at the edges. 4. The Model Distance. Move your model at least 6-8 feet out in front of your green screen. Many people "Way Over Light" and even flood the background with over brightness. This causes a reverse bounce of bright green light to come back onto your model. This ruins the edges with false information. Use a light meter for measuring the background illumination... make sure the exposure is not more than 1 F stop above your main key light reading. Magenta is the opposite of green... yellow is the opposite of blue... you can sometimes use a small hair light with a 1/2 strength gel to neutralize the contamination in the body edges or hair. Remember: The further the model is away from the background...and the better the background brightness is under control...the more you wont have to worry about bad edges from contamination. 5. Kinds of Hair + Complexity. For me black hair is fairly easy to cut accurately because it has good contrast with the background. Dark Brown hair cuts really well for me. Reddish or purple hair cuts out fairly well. Blond hair IS TERRIBLE to cut out. Blond hair is sometimes translucent or even almost clear...the green background light shows right through the strands... and makes it almost impossible for the program to tell if the hair is blond or green... often it actually does look green... because blond hair picks up contamination colors real easily. I almost never use a hair light on a blond im cutting...the light makes the strands become several shades of blond...and that really confuses the program further. Put your hair shine in at the post production stage. 6. Masking Tools Inside Photoshop. In Photoshop... under the Main Menu > Layer > Matting... there are 4 special masking tools that will help remove some of the ugly, tell tale white or black outlining in your hair or body cutouts. They work real well. There is also a Defringe Tool and a De-Contaminate function at that same location that is also really helpful in cleaning up tough masks. There are also "Refine Edge" tools in the Photoshop Properties dialogue... that can be used to refine your mask for better results. There are about 5 functions that can be used to help make your cutout look better in there. You can also use the "dodge and burn tools" on just your Mask Only... to make some light areas lighter or some dark areas darker... or vise versa...this gives your mask more resolving power and you can control where it happens. Dodging and burning the cutout mask can sometimes make a very significant enhancement in your final end results. OP...Good luck in your green screen journey! When I remember to address all of these elements in my green screen sessions... I can usually get single strands of hair to cutout cleanly without any artifacts. Its amazing when everything comes together well ! Apr 25 16 03:21 pm Link |
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