chroma key question

musman wrote on 7/30/2004, 4:11 AM
I'm shooting a new short where I'm trying to show the screen of a palm pilot. Unfortunately, the first time we shot the image was too soft, dim, and generally hard to read. Part of the problem is that it's not a color screen.
So now we're going to reshoot and I was wondering if I should try:
1- Putting a piece of greenscreen on the Palm Pilot and chroma keying out the screen and replacing it with a still photo.
or
2- Getting a Palm Pilot with a color screen- unfortunately the palm pilot we've used to this point is black and the only palm pilots available these days are silver. So, I'd have to try to replace the silver with the black of the older palm pilot.
I suppose I have to make a decision as we're shooting on film and this is really getting expensive. So, does anyone have any thoughts?
thanks ahead of time for any help.

Comments

Grazie wrote on 7/30/2004, 4:35 AM
R U using V5b? Bezier Cutaway using Key Frame moves? - G
Grazie wrote on 7/30/2004, 4:40 AM
A mini lcd that "looks" like a Palm Pilot?
Grazie wrote on 7/30/2004, 4:40 AM
Cutt he guts outta the PP and stick in your own LCD with the video in it!
JaysonHolovacs wrote on 7/30/2004, 7:48 AM
Green screening can be done but you have to make sure the lighting is uniform for it to work well. Might be easier on a pilot than a full size scene. Bezier curves would work well if the scene doesn't move too much, otherwise, it's a lot of work.

How about track motion? Instead of trying to make a clear portion of the image to see the generated screen through, how about using track motion in 3D to align the fake screen over top of the real one and give it the right angle? Then the text on the screen will have the right perspective to it, where it might not have if you have a flat, 2D image appearing through a transparant hole.

-Jayson
Grazie wrote on 7/30/2004, 7:53 AM
3d track motion . .that's the way! - G
Fleshpainter wrote on 7/30/2004, 10:52 AM
Actually did this once, looked quite real. Painted a dead TV screen blue and placed another track behind it. It's not that hard. Green is better unless there is foliage or something else green to screw it up. The above mentioned techniques should be used for warping the picture to make the perspective look right.
musman wrote on 7/30/2004, 12:14 PM
Wanted to thank everyone for the help. I did try and use the rotoscope or bezier curves thing and it does work okay. But the palm pilot is hand held, so it does move around a bit. The actor also moves his hand and a pen in front of the palm pilot at one point to push an onscreen button. I just thought that would be some pretty tricky keyframing to cut out on top of a cut out where a chroma keyer would do a lot of that work for me. Am I missing something here?
epirb wrote on 7/30/2004, 2:50 PM
does the old P/P have a black frame all around and you 've got shots of the Face already? If not i have an old color screen Ipaq(has a black sleeve) you could use.
Other than that I like Fleshpainter's idea,...you can buy those screen protector stick on film deals they make for palms and color that green.
JaysonHolovacs wrote on 7/30/2004, 2:57 PM
If you actually have something moving in front of the screen, then yeah, Chroma might be your best shot, because the track motion idea can only work if it's on top, and Beziers will be a pain.

Unless of course you consider re-composing the scene in such a way that it won't happen... sometimes it's easier to work around the technical diffilculties than to fight with them... depends how much time you are willing to spend on it.

-Jayson
Fleshpainter wrote on 7/31/2004, 1:35 AM
The chromakeyed palm pilot is your top layer. Next place your insert picture behind the chromakeyed palm pilot. Now the hand will be in front and small movements won't matter. You won't really have to crop the bottom layer because the top layer will cover it. Just re-size, warp, and twist the bottom layer to match what the palm pilot is doing. Use the level slider to make the top layer transparent so you can see behind it while making the adjustments. When you're done be sure to set your levels back to 100%.
musman wrote on 7/31/2004, 1:05 PM
Thank you everyone for your help! I did my first chroma key test last night. I had ordered a lot of green screen paper roll a while ago and cut out a piece big enough to fit the screen. And the importance of even lighting is now fully appreciated.
This might work, but we'll hve to wait and see. I'm a bit concerned about a shadow from the actor's hand and his pen when he reaches out and pushes a button on the screen. That actually presents a few problems. All I can do is give it a go and see what happens I suppose now.
Wish me luck!
johnmeyer wrote on 7/31/2004, 3:52 PM
When it comes to masking, I always find lots of ideas by looking at this demo:

Cat Demo

You will find that it involves both compositing and masking out foreground and background. After you click on the link above (which takes you to a Vegas thread), click on the "this page" link.
farss wrote on 7/31/2004, 4:23 PM
So long as most of the arear you are trying to key is preserved you can extract the keyed area as a mask and then tidy that up.


Bob.