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EEFX
FREQUENTLY ASKED QUESTIONS
How do I
clean the backdrops?
Can I walk on the green
screen?
How should I light the backdrops?
MiniDV vs Solid State, P2 Memory Card, and
Hard Drive cameras. What is Better?
Do the seams cause a problem
when color keying?
Do grommets or Rod-Pockets come with the standard orders?
Does it cost extra to add extra features?
How much do grommets Cost?
How long
will it take for my order to process?
What is your
standard shipping carrier?
How is the
fabric shipped? Do you fold it?
How
should I store my backdrop?
How do I remove wrinkles?
How does foam-backed fabric compare
to other fabrics?
What makes
a larger Chroma Key backdrop better?
What Color is Better
(BLUE or GREEN)?
How do I clean the backdrops?
You can wash this fabric in
the washing machine then hanging it up to dry. For larger
backdrops (too big for a washing machine), put a little soap on a
cotton rag (mild soap or laundry detergent) then run the rag under
water to dilute the soap (if the soap is not diluted, it will foam
up). Use the rag to spot clean the fabric. If the spots are bad,
you can also use stain remover or spray it down with a water hose.
After your done, hang out to dry or use a hair blow-dryer for spot
drying. The important thing is to clean away any excess soap and let it
dry completely before using. If the backdrop is not dry, dirt might attract to
the wet spots. Don't be scared to use lots of soap if necessary but
don’t use any chemicals that will harm synthetics (IE: 409, bleach,
Tilex, etc).
Can I walk on the green screen?
This fabric is very durable and will not rip or
tear when walking on it. The Chroma key fabric is made of very strong
nylon/polyester so you won't have problems with it ripping. To give
you an idea of how strong it is, we've attached 40lbs of lead weight
to a 1/2inch wide strip without it ripping
(click here to see image). It is also very
difficult to cut. You would need sharp scissors or a matte
knife to cut it. When walking on it, just clean any loose mud
or dirt off your shoes.
How should I light the backdrops?
Daylight corrected HMI's are
wonderful if you can get them. To keep cost down we
often use 1k Tungsten hot lights with diffusers or umbrellas
instead. They are easier to find and cost less. Most Mini DV
cameras as well as any HD camera should have white
balance options with a settings for Tungsten. If you are shooting on
film, then HMI's would be a lot easier to work with. If you can't
get access to HMI's when shooting film, you will need to correct the
Tungsten lighting using optical filters. We would recommend consulting your
camera DP for more info.
The best way to successfully
pull a key is to evenly light the entire backdrop. Try to eliminate
any hot spots inside the frame. Light the screen from the sides at 45 degree angles.
Place 1-3 lights (w/ diffusers or umbrellas) on each
side of the screen. Placing your actor 7ft -
10ft away from the backdrop will eliminate most shadowing problems
and also eliminate a lot of the color bleed issues. Keeping the
actor this far away also makes it easier to light them
separately. The way you light your subject/talent depends a lot on the scene
you’re compositing them in. After lighting the talent correctly, we
often place a rim light either behind/above or to the side of the
screen shinning on to the back. This gives you a good
separation line and also helps eliminate color bleed issues.
MiniDV vs
Solid State, P2 Memory Card, and Hard Drive cameras. What is Better?
MINIDV:
MiniDV should not be confused with an uncompressed format. It is
indeed a digital format, but it is compressed the moment you
recorded to the tape. The camera records to the tape at a 4:1:1
color space. To keep it simple, for every scanline (720 total NTSC)
every group of 4 pixels in a row are sampled down to a single pixel.
So basically, the color channel on a MiniDV tape is actually only
180x480 chroma samples and not 720x480. The reason it doesn't looks
like this is because the Luminance channel is recorded at the higher
sample, which give the eye the illusions of color shift. That is why
it is difficult to work with Green Screens on MiniDV. If you've
every attempted to color key DV footage, you will see white colored
stair step patterns on the edges. This can be minimized
significantly by using a good keying package. Some of the better
color keying programs have built-in settings to eliminate these
artifacts.
SOLID STATE AND STRAIT TO HARD DRIVE FORMATS:
Some strait to hard drive or memory card cameras (Example:
Panasonic’s HVX-200) can record at a 4:2:2 color space (or better).
To keep this from being a novel, we won't explain too many details,
but basically the color pixel information on the Panasonic memory
card camera has twice as many color pixels as a miniDV camera even
when recorded at the SD 720x480 TV resolution. This means the stair
step patterns are cut down by half compared to a miniDV camera.
HDV
format:
HDV
cameras are becoming more readily available and extremely cheap. Be
warned that all HDV cameras that record to tapes are compressing
chroma channels at a 4:2:0 ratios and in turn, your chroma channel
on HDV is 1/4th compressed simliar to DV 4:1:1 footage. Really the
main difference is the image size, but your stair step problem will
be just as bad on HDV footage.
Recommendation:
We
recommend a 3CCD professional 4:2:2 (1/2 compressed chroma channel)
or a high-end 3CCD 4:4:4 (uncompressed chroma channel) camera
format.
Will the seam cause a
problem?
The seam is so small it
should
not effect your color key. For most productions, the camera will
also be at least 8 feet away, making it hard to notice the seam.
Click here
to see a shot that utilizes a seamed backdrop. If you look
closely, you'll see the seam next to the actor's elbow. It is not
large enough to effect the keying.
Do grommets or Rod-Pockets come with the
standard orders? Is there an extra charge for these additional
features?
Unless specified otherwise in the title or
description of our item/auction, rod pockets or grommets are not
included with the standard backdrops and are an additional cost.
How much do grommets
cost?
The price varies depending how
many edges you want
modified and the space you want between each grommet (standard is
every 2ft).
In order to give an accurate quote, we need to know specifics about
what you are looking for. . The edges on grommet orders are normally double tucked
(folded over at the edges for reinforcement) and sewn down before
grommets are placed. Double tucking the edge takes extra time to
manufacture, but makes the edges stronger. This extra
strength insures the grommets won't rip out, especially on larger
backdrops.
How long will it take for my order to process?
Order
manufacturing times changes depending on current demands. The
estimated processing and manufacturing times are posted in the
shopping cart and order confirmation
email. This is generated from an average of our current order
processing and is not a guaranteed a shipment date. In
general, the larger customized backdrops tend to have longer
processing times. Although faster shipping methods are normally processed first, don't assume your backdrop will arrive in 1 day if
you pay for overnight shipping. Manufacturing times also applies to
Overnight Air and 2-Day air orders. Expedited processing is
sometimes available for a minimal service fee. For more information
please call our sale office at (805.462.EEFX).
What is your standard
shipping carrier?
Because most of our orders require large boxes, we normally ship via FedEx Ground. Depending
on the size and priority of the package or the ship to location, UPS
or USPS Air Mail may also be used.
How is the fabric
shipped? Will it be folded?
The backdrops are rolled up then folded to fit in
an optimally sized box. This saves you money on shipping. We will
gladly ship the backdrop rolled instead of folded, but it is
considered over sized and can cost 2-3x more to ship. Please
contact us directly at
sales@eefx.com for info regarding the rolled shipping method.
Are you worried about
wrinkling? You should be happy to hear that the foam core of
our fabric bounces back amazingly well. For storage, fold the fabric
at the seam, then roll up on a pole or on itself. Another option is
to loosely fold it up. Remove every month or two and refold
differently each time to eliminate any creasing.
How should I store my
backdrop?
The best method would be
to fold the fabric at the seam, then roll the fabric up on a pole or
on itself. Another option is to loosely fold it up. Unroll it
every month or so and refold differently each time to eliminate any
creasing. If you keep it folded, once you hang or lay it out, the
foam core bounces back amazingly well
How do I remove wrinkles?
Once you hang or lay the
fabric
out, the foam core bounces back amazingly well. Let it hang up for a day or so, depending on the
extent of the wrinkles and the wrinkles should disappear. If
you need them out faster, fill up a spray bottle with water and
spray the back side (in the area with wrinkles). The water will
speed up the foam expansion process and remove wrinkles within
30-45Min's. Use a hair blow drier if you need to dry the fabric
quickly. The foam back fabric is the best in the industry when it
comes to wrinkle removal.
How does foam-backed fabric compare to other fabrics?
Our fabric is used by most
visual effects supervisors and is preferred by artists because of
many reasons. First of all, it is composed of a three layer laminate design.
The layers include a foam core center, nylon mesh backing, and
chroma key diffusion face. The nylon backing makes it almost impossible to tear. The foam core
gives it the ability to stretch and also bounce back from wrinkles.
The chroma key face layer is very strong and is composted of a
series of tiny loops that diffuse light for a more evenly exposed
backdrop. There is no other fabric like it in the industry.
Although it may cost more to manufacture compared the other single
layer woven fabrics, our prices are extremely competitive for quality
foam-backed fabric.
EEFX.COM is owned by a visual effect
artist that has worked on projects ranging from feature films to
commercial spots and has used all different types of chroma key
fabrics and paints. As most visual effect supervisors will agree,
Foam-Backed Fabric is FAR SUPERIOR because of its
versatility, durability, ease to evenly light, thickness, color
fastness, diffuseness, and strength.
What makes a larger chroma key backdrop better?
When the backdrop is smaller, the actor has to stand closer to the
screen.
If your subject is
to close to the screen, you may have problems due to the chroma key
color reflecting off the screen and bouncing onto your subject. This
is called "color bleed" in the industry. Too much bleed can cause
the subject to become transparent where the green hits their skin
and clothes. Bleed can be removed by bouncing white light into the
problematic areas or by moving your actor further away from the
screen. This is one reason why a large backdrop is extremely
beneficial for a successful color key. The larger the backdrop, the
further you can pull your actor away from it.
Having a larger backdrop also makes it easier to light the backdrop
separate from the subject. With more space between the backdrop and
the model, you can easily light the backdrop without casting dark
shadows on the back of the screen. We
recommend placing the subject at least 8'-10' away.
A larger screen will also give you
more range of camera movement. If you plan on shooting multiple
angles (IE: close-up, wide, side, low POV, moving shots, etc.) then
make sure your screen is large enough for its application.
What color is better (BLUE or GREEN)?
Both blue and green work very well for color keying. Green tends to
be more popular for DV because the camera's CCD is more sensitive to
the frequencies in the green color spectrum and requires slightly
less light. Blue, however, can be easier to work with when color
bounces onto the subject (bleed). Most of our customers purchase
green, but both colors are industry standard. Keep in mind that the
Chroma key backdrop shouldn’t resemble colors in your scene. For
example, if you are taking photos of a person wearing green clothes,
then Chroma key Green may not be your best choice. The same is true
for blue. If your subject is wearing blue clothes, then you
shouldn’t use a Chroma key Blue backdrop. Photography studios often
buy one of each color so they have a Chroma key screen for any
situation.
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