Chroma Key Question
 

I have been asked by a local health authroity to shoot a short film displaying the correct techniques used in emergency resuscitation. For safety reasons this can't be done on a 'live' person (its normally done using a dummy), however, the end result is that they want me to present the film looking like its being done to a real person.

OK...so i've intend to film the trainer performing the chest compressions to 'thin air', then film a real person lying on the table against a blue screen and key these two together.

Now the bit i'm struggling with....is there a way in vegas to convincingly make the chest of the 'real' person appear to be being compressed (say 2 inches) ?

My first point would be to ask you why complicate things? You can easily make it look like he's performing the procedure on a real person without the CSO.

I'd be inclined to shoot it with a real person pretending to drown etc, being dragged out of the pool etc but as soon as he starts compressions keep the real person out of shot for example. There are dozens of ways to shoot that.

I think you wanting to use CSO will really make this a difficult job for you, it could lead to all sorts of problems to overcome.

Keep it simple! It'll look much more realistic!

They specifically want a 5 second wide shot showing both the person performing the chest compression on the unconscious individual.

Then have them find a volunteer and have him sign a waiver. They are making it unnecessarily difficult for you. As a member of a fire department we do CPR video quite often. I can see no reasonable reason to have a shot such as you describe. There are many creative ways to make it appear that it is being done on a live victim without a single wide shot showing both continuously in the frame.

find a trick, use the dummy, add head of a real actor in post, mold a silicon dummy chest to add to the actor, got to the nearest hospital where they do that probably everyday, go to the closest morgue and use a real dead body....

Yes I already suggested we find a dead body to use from the morgue but it didn't go down too well !!

Looks like i'll have to keep on at them and try and convince them that its not going to look too good, and will probably end up looking less convincing than just using a 'dummy' as with other CPR sequences.

cut a part from one of these many "hospital" series...they are doing this every 5 minutes...

You have not mentioned anything about the shoot but can't you use the dummy and a person dressed the same (fully clothed) and people standing around at just the right locations to give you a wide shot and still look real? Everything else is a combination of real and dummy and edited right it could look pretty good. I think this is clever filming and editing more than anything else.

I shot a corporate earlier this year and the talent is now a leading character in a UK daytime BBC soap called 'Doctors'. We keep in touch and having read this thread I asked he if she could find out what they do at the BBC.

They do exactly as Harold suggests. They have an identically clothed dummy which is cut in with the real person. Nothing overly complicated, just clever shooting and editing. Of course, this assumes your patient is clothed.

Someone earlier made the assumption that the patient was being pulled, drowning, from a pool - if this is the case then you will clearly have to find a VERY realistic dummy!

This may not suit your clients needs but if it is the case that to perform this kind of resuscitation on a person who doesn't need it is actually dangerous, then could you maybe make that point in the video and explain that this is why you are using a dummy? No idea who the intended audience is but you can bet your life someone will want to try it out on their buddy!