#Blue Screen Problems
17 messages in this thread
Help! I am having trouble with the color Blue!
I have taken on a project that requires compositing scanned bluescreen footage
within some 3D animation. Here's the hitch…the color blue has some slight
red and green values mixed in. So, when using LW's foreground keyer, by
setting the low and high clip with more than blue (I have to add some red and
green), I not only (finally) clip out the blue, but part of the central image!
SO, I need a shade of blue paint with no trace of red or green, or
I need to color correct the back ground lighting and reshoot the footage, or
I need to find some program that will only clip a selected hue (either R, or G,
or B) from a range,
Or I need an ULTRAMATTE system that works with the toaster!
I have some ULTRAMATTE SUPER BLUE paint coming from Rosco…we'll see how that
works…but If anyone else has had this problem, and found a fix, please let me
know!
Thank You
Glen
Glen PLEASE try Imagemaster R/T Before going thru the expense of a
RESHOOT. I've had Excellent Results by simply shooting in front of a
Photographer Backdrop. Imagemaster's Variance feature lets you allow for
differences in shade due to lighting or shadws etc.
You need to paint a smooth backdrop with that Ultimatte blue your ordered
AND light it brightly and evenly AND use Imagemaster.
Background color and bright, even lighting are really key.
(Key, get it? <g>)
I once used a stretched white sheet as a backdrop. Lit the hell out of
the sheet, then lit the foreground subjects normally. I set the camera
iris to a bit underexposed for the foreground subjects. This made the
background sheet overexposed and clipped to 255,255,255 (or very close)
when I digitized it. I bumped up the brightness a bit on each frame which
ensured the entire background was pure white, and that enabled me to strip
it out cleanly. Worked like a champ. That was a while back and I had $0
budget. You'll get better results using Imagemaster's color variance
control. However, if I were doing this for pay, I'd get an MX-1 or a
TARGA+.
-Jerry
Good tips on the backdrop! I wish I just had the ultramatte system….maybe
Allen will write it into LW 4.0!
:}
GM
To further Jerry's answer, Imagemaster has a new way to specify color keys, in
addition to the old RGB. It now keys by hue as well. This means you can have
highlights or shadows in your background, and Imagemaster will pick them up
without forcing you to enter a variance that would've made the old RGB key pick
up bits of foreground objects as well.
Blaq!
It sounds like the Imagemaster programmers are trying to develop a Ultramatte
system for the Amiga! Now, If they are, I hope they will take it all the way!
GM
Would you, or anyone else, care to elaborate on this process?
It sounds like a very useful technique. As a new IM r/t user (2 months
old), I'd love to know how to accomplish this technique.
Stephen Bailey
Sawyer & Bailey Film and Video CIS # 72773,2451
Choose Adjust Background Color, set the color thats close to the color you
used to shoot against such as Blue, then set the Variance Slider to approx
30-50 in that range. Load the Background you want into the Secondary
Buffer and do a Color Keyed Rub thru or Color keyed Merge. To do a SERIeS
would need a Arexx Script or ALOT of patience. The Arexx script would
likely be fairly simple maybe 10-15 lines of code. I think we should have
Ben add a tutorial of this kind to the Appassist Docs.
I agree about the tutorial.
And, thanks so much for the details. I'm doing some FXs for a friend's
film, involving mucho keying. Lots of pseudo-television anchor stuff.
Stephen Bailey
Sawyer & Bailey Film and Video CIS # 72773,2451
Film???? Shot on Film??? What are you using to Scan the Film into yer
'Puter? Sounds Like ALOT of fun. I hope my explanation was coherent enuff
for you to follow. I tend to ramble and am not a very good teacher.
Maybe ya can get me in the credits as "Technical Consultant"
hehehehehehehe
Is the Film a Student Film or a Actual Independent production? Theatrical
release or Direct to Video? Detaisl Man Details… This way yer Amiga
Brethren can check out yer Work……
My friends film is his Thesis film, required for completion of an MFA from
Columbia here in Chicago (where I'm also an MFA candidate).
There is a ton of TV material in the film, lots of anchors, an election,
etc. We're doing the CGs for it, as well as some other stuff.
Right now, he's shooting the video portions, which we will take and key
CGs onto, etc.
Then, he will incorporate these images into the film using monitors and a
Arri (I think, I'm not sure what camera he's using) running at approx. 30
fps (29.???) in sync with the monitors.
If he wins a Student Academy Award, you may hear about the film.
Otherwise, unless you frequent the student screenings here in Chicago,
you'll probably never know it exists (unless it turns out great and I
start bragging around here <g>).
The credit is yours. I'll let my partner (the film's producer) know. No
guarantees, though. <G>
BTW, your explanation was right on. I haven't tried it yet, but you were
perfect in giving me the buttons and areas within which to work. IM r/t is
so complex and layered. Finding an effect is often hard because things are
spread out all over the place. There is logic. But, the quantity of
options is quite daunting. Then again, I love that. Power and more power.
Choice and more choice.
Take care.
Stephen Bailey
Sawyer & Bailey Film and Video CIS # 72773,2451
Glad you were able to follow my explanation. Well if yer Buddy becomes a
Famous Director we'll hear about EVERY Film he's ever done including stuff
shot on 8mm when he was 6 hehehehehehehe.
Good Luck to you both for your MFA(whatever that is) More Fat Angus
perhaps? Hope the film comes out well.
MFA = Masters of Fine Arts. (i.e. Gradual School <g> )
Stephen Bailey
Sawyer & Bailey Film and Video CIS # 72773,2451
Thanx, I figgered out what MFA was after I'd posted. Good Luck tho I think
More Fat Angus is more impressive hehehehehehe
Stephen,
Load an image of a model standing in front of a solid background as primary.
Load the desired background (e.g. an alien landscape, if this is a Peter Greci
anim B^) as secondary.
Choose the desired area selection tool from the palette. Enter Process/Define
Color.
Outline a background area containing a representative sample of the shades to
be deleted. Imagemaster will analyze the area and come up with a base color +
variance setting.
To use this setting in the following operations, switch to the "Color keyed
selection" tool, two left from Redo.
Click on "Mask". This lets you preview the active area in the blue-and-grey
display next to the memory gauges. SELECT "SET TO FOREGROUND", "KEY ON HUE" and
OK.
If the preview masks shows too little of the background being selected, or
conversely, parts of the foreground objects being selected, go back to "mask"
and adjust the Var (variance) slider accordingly.
When you think you've got a satisfactory mask, click on "redo" to _lock-in_ the
current area selection.
Go to the main panel, then Compose/Linear Compose/Merge. Imagemaster will let
the secondary image show through the solid background. Because you created the
image mask using "key on hue" rather than "key on RGB", Imagemaster will be
much more selective in isolating the background, even if shadows or highlights
change its brightness.
Blaq!
Thanks, Charles.
You and Peter have given me much to go on. I'll let you know how I come
out of all this.
Stephen Bailey
Sawyer & Bailey Film and Video CIS # 72773,2451
😉 I Want a Model of the Alien!!!! So much so That I'm trying to come up
with the $$$ for Impulses Digimaxx!!!! I do have a Lovely Plastic Model of
the Alien poised for attack, sorta protecting an Egg. It seems to be the
perfect size for the Digimaxx. Tho I can't wait till Affordable Auto 3D
digitizers appear. defining enough points to get a decent model is going
to be time consuming as H*LL methinks.