FX: Blood, Eyes & Composite at DVinfo.net

Go Back   DV Info Net > Special Interest Areas > Techniques for Independent Production

Techniques for Independent Production
The challenges of creating Digital Cinema and other narrative forms.


Reply
 
Thread Tools Search this Thread
Old December 5th, 2005, 02:42 AM   #1
Tourist
 
Join Date: Dec 2005
Posts: 4
FX: Blood, Eyes & Composite

I've got a few questions regarding effects and am hoping someone out there with experience of them can help me out. I've checked the net and looked up techniques, but to have advice from some of you guys would be great too.....

Blood - what's the best recipie for fake blood? I tried one I found on the net and it was terrible. Also, I'd like to splatter it a bit on someone's face at the point of a wound being inflicted. What would be the best way to do that?

Eyes - I need to make someone's eyes completely black. No white, no cornea, no iris, just black. Any idea how I could accomplish this in post? I had thought of rotoscoping but that could be pretty lengthy. Or would I save time and hassle by getting lenses or something?

Compositing - I need to have an actor approach a version of himself sitting on a bench. A lot of this can be done with angles and cuts, but I'll be needing shots with 2 versions of the same person in frame, interacting with each other. What's the best way?

Many thanks in advance for any help/advice you guys can give.

Doonae
Chris Dunne is offline   Reply With Quote
Old December 5th, 2005, 06:12 AM   #2
Wrangler
 
Join Date: Oct 2003
Location: DFW area, TX
Posts: 6,108
Images: 1
Chris,

The best recipe for fake blood if it will be in your mouth is corn syrup mixed with red food coloring.

If you want the entire eye area black, that will have to be done in post but there are contacts that will make the actors pupil and iris solid black. Be forewarned that some of the cheap contacts along with improper use can lead to serious eye infection. So if you go this route, be sure to have the lenses fitted with instructions for proper cleaning and wearing.

Can't help with the compositing shot.

-gb-
Greg Boston is offline   Reply With Quote
Old December 5th, 2005, 07:44 AM   #3
Inner Circle
 
Join Date: Sep 2002
Location: San Mateo, CA
Posts: 3,840
Lots of variations on the blood recipe, but it's basically corn syrup and food coloring. My mix is a ratio of 3:1 (3 parts syrup, one part water) Add red food coloring, then a touch of blue to darken it. (SOme people like to use a touch of green. Check under your lighting conditions)

For blood on costumes, baby shampoo works best. Buy clear brand, with 'no dyes'... then add food coloring as per above.

Spattering on camera can be accomplised a number of ways, depending on how far away from your 'sprayer' the 'sprayee' is. Could be a simple as putting a bunch on a spoon, then flinging it at their face. Could be loading a syringe and squirting it. (Squirtguns tend to gum up with a thick base... try diluting at 1:3 if that's the case). High pressure sprayers work GREAT for long distance, high volume throws, and are pretty much the industry standard. (Pick one up at a hardware store... in the garden department.)

Greg's advice on the contacts holds. The good ones are expensive, the cheap ones dangerous.

Dual images are usually accomplished with a variation on a 'split screen' composite. DO a search for that on the forum. It can get complicated if the camera is moving.
Richard Alvarez is offline   Reply With Quote
Old December 5th, 2005, 03:14 PM   #4
Regular Crew
 
Join Date: Nov 2005
Posts: 49
They made people's eyes blue in Dune, it means rotoscoping. If you want to do less, have them wear sun glasses or something.

http://ryanw.michaelfrisk.com/ryan-w/index.html
That site has some info and example on cloning & compositing.
Adam Keen is offline   Reply With Quote
Old December 5th, 2005, 06:00 PM   #5
Regular Crew
 
Join Date: Sep 2005
Location: Montreal, Canada
Posts: 142
For the blood, the usual recipe is corn syrup and food colouring, but I've had great results with a flour-based recipe, though it takes more preparation. Take a look at this page:

http://www.exposure.co.uk/eejit/blood/blood.html
(look at the MB2 Blood recipe, but there are other recipes as well)

As for compositing 2 people in the same shot, it all comes down to being well prepared. Shoot some tests, and keep it simple. Some tips:

- When you use a split screen for a long dialog scene, it's really hard to get the two halves to sync. Get extra coverage in close-ups to patch it up.
- If shooting outside (as I assume you are): light levels can change as the sun goes behind clouds: be aware that it can make the 2 halves of the shot look different.
- Make sure your exposure is locked as well as the focus. You want the same exposure and focus distance for both halves of the shot.
- Make the split line between the two halves slightly feathered.
- Try to make the split line static for the whole shot. If it moves, it might make the division stick out. I'm not saying don't move it, but be aware that it will be harder to make it match.
- Choose the position of the split line wisely. If there are trees in the background, then leaves moving in the wind might break the illusion along the split line. It might be better to set the split line along a solid object, like a lamp post. Frame the shot so you can use the background to your advantage.
- The split line doesn't have to be a line but can follow around features of the background.
- Avoid having the line go through a continuous feature, like the sky, which can make it difficult to have a match.
- You can cheat it for some shots: use another actor with same hair colour, build and clothes for an over-the-shoulder shot, or a wide shot where one of the characters has his back to the camera. This would allow you to keep the camera mobile. You can even frame the shot lower if you can't find someone with the same hair colour.
- When you say you want real interactions, do you want the characters to move in front of each other? If that's the case, then a simple split screen won't do it. You either need to shoot the front character with a blue/green screen, or do some rotoscope work in post. If the overlap is complex, then keying is better, but for a short overlap, rotoscoping will be a whole lot easier. For instance, if the characters are talking, and character A's hand moves in front of character B for a second or two, then rotoscope it.
- If you want your characters to make physical contact (hand shake, exchange an object), then the OTS trick from above with another actor, or an insert of the hands is the easiest way to do it. Even for a fight scene, it's easier to cheat it with another actor.
Jean-Francois Robichaud is offline   Reply With Quote
Old December 6th, 2005, 08:58 AM   #6
Tourist
 
Join Date: Dec 2005
Posts: 4
Quote:
Originally Posted by Jean-Francois Robichaud
For the blood, the usual recipe is corn syrup and food colouring, but I've had great results with a flour-based recipe, though it takes more preparation. Take a look at this page:

http://www.exposure.co.uk/eejit/blood/blood.html
(look at the MB2 Blood recipe, but there are other recipes as well)

As for compositing 2 people in the same shot, it all comes down to being well prepared. Shoot some tests, and keep it simple. Some tips:

- When you use a split screen for a long dialog scene, it's really hard to get the two halves to sync. Get extra coverage in close-ups to patch it up.
- If shooting outside (as I assume you are): light levels can change as the sun goes behind clouds: be aware that it can make the 2 halves of the shot look different.
- Make sure your exposure is locked as well as the focus. You want the same exposure and focus distance for both halves of the shot.
- Make the split line between the two halves slightly feathered.
- Try to make the split line static for the whole shot. If it moves, it might make the division stick out. I'm not saying don't move it, but be aware that it will be harder to make it match.
- Choose the position of the split line wisely. If there are trees in the background, then leaves moving in the wind might break the illusion along the split line. It might be better to set the split line along a solid object, like a lamp post. Frame the shot so you can use the background to your advantage.
- The split line doesn't have to be a line but can follow around features of the background.
- Avoid having the line go through a continuous feature, like the sky, which can make it difficult to have a match.
- You can cheat it for some shots: use another actor with same hair colour, build and clothes for an over-the-shoulder shot, or a wide shot where one of the characters has his back to the camera. This would allow you to keep the camera mobile. You can even frame the shot lower if you can't find someone with the same hair colour.
- When you say you want real interactions, do you want the characters to move in front of each other? If that's the case, then a simple split screen won't do it. You either need to shoot the front character with a blue/green screen, or do some rotoscope work in post. If the overlap is complex, then keying is better, but for a short overlap, rotoscoping will be a whole lot easier. For instance, if the characters are talking, and character A's hand moves in front of character B for a second or two, then rotoscope it.
- If you want your characters to make physical contact (hand shake, exchange an object), then the OTS trick from above with another actor, or an insert of the hands is the easiest way to do it. Even for a fight scene, it's easier to cheat it with another actor.
This is all great man, thanks.
Chris Dunne is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

Professional Video
(800) 833-4801
Portland, OR

B&H Photo Video
(866) 521-7381
New York, NY

Z.G.C.
(973) 335-4460
Mountain Lakes, NJ

Abel Cine Tech
(888) 700-4416
N.Y. NY & L.A. CA

Precision Camera
(800) 677-1023
Austin, TX

DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > Special Interest Areas > Techniques for Independent Production

Thread Tools Search this Thread
Search this Thread:

Advanced Search

 



Google
 

All times are GMT -6. The time now is 04:42 PM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2017 The Digital Video Information Network