Footprints in snow without people

AlanADale wrote on 1/7/2010, 2:34 AM
I saw a video on Vimeo a while back showing the effect of someone walking down a hallway leaving wet footprints although no person was to be seen. It was as though an unseen Ghost was walking whose only presence was leaving these wet footprints.

I'd like to achieve this affect but with footprints in snow. Anyone have any idea of how to go about this and is it achievable in Vegas Movie Studio Platinum?

Comments

Chienworks wrote on 1/7/2010, 3:23 AM
If your field of view is close enough you can have someone walking some sort distance beside the path with a pair of shoes on long poles. Have that person make each foot print one at a time, remove the shoe, then take a still photo of each additional footprint. Drag all the stills in order onto the timeline with a very brief crossfade inbetween.

If the field of view is far away then you might be better off doing it in a photo editor, creating a foot-shaped mask, and adding a bump mask and darkening each footprint shape. Save a new image as you add each footprint, then import into Vegas as above.

Real low-ball method would be to have the person walk backwards in their own steps after each new additional step and take a still picture after they're back out of the frame. Then the walk forward again in their own steps to make the next footprint. Problem with this is that they'll mess up occasionally and older footprints will start getting bigger and fudgier.
GerryLeacock wrote on 1/7/2010, 3:27 AM
Just off the top of my head, because I've never tried it, but...

Take 2 stills. One of the snow covered path. Take a second one with foot prints in it. But them on separate tracks and slowly blend one into the other. Something like that.

If you're short of snow, I can send you some.

Gerry Leacock
Winnipeg, Canada
AlanADale wrote on 1/7/2010, 4:30 AM
Ha ha Gerry LOL. Snow is something that we're definitely NOT short of here in southern Germany.

Some interesting idea so far - thanks.
Eigentor wrote on 1/7/2010, 6:21 AM
How bout having someone dressed in one color (not white) walk through the snow and then use the chrome effect to remove them from the video, like the green screen thing.

Viel Glück und sagt hallo zum hofbrauhaus für mich.
AlanADale wrote on 1/7/2010, 8:14 AM
Reply by: Eigentor
How bout having someone dressed in one color (not white) walk through the snow and then use the chrome effect to remove them from the video, like the green screen thing.

Now that idea I like - any possibility of linking to a tutorial on how to achieve this?

Reply by: Eigentor
Viel Glück und sagt hallo zum hofbrauhaus für mich.

Will do but it'll have to wait until October. Being approximately 150km north of Munich it's not exactly what one would call my local pub.


MSmart wrote on 1/7/2010, 8:58 AM
The way I would do it is to have the vidcam on a tripod and don't move it while filming. Shoot a long enough segment of just the snow longer than the duration of the effect desired. Have a person walk across the field of view. Using other tracks if needed, slice and dice the footprints to add them in in sequence keeping the previous footprints in view. Maybe use a fade-transition to have them "appear" more softly rather than abrubtly appearing.
Eigentor wrote on 1/7/2010, 10:45 AM
Should be easy, right? I've only been at this for a year, but do a search on "chroma key".

You would video the person walking through the snow, dressed in one color dfferent from any others, then add the chroma key video FX to the clip and select with the ink dropper the person in the video. It should then remove them from the video. directly below on the next track, add identical video without anyone, obviously taken before they left the foot prints. This should fill in with background (snow, trees...), where the person was.
richard-amirault wrote on 1/7/2010, 11:46 AM
How bout having someone dressed in one color (not white) walk through the snow and then use the chrome effect to remove them from the video, like the green screen thing.

You mean like:

http://www.thedvshow.com/250-for-a-green-screen-body-suit-never/

http://cgi.ebay.com/Chromakey-Green-Screen-Body-Suit---Video-Effects-Muslin_W0QQitemZ370315398484QQcmdZViewItemQQimsxZ20100104?IMSfp=TL100104217005r4542

http://www.chromakeysuit.com/

AlanADale wrote on 1/7/2010, 1:09 PM
LOL - my other half is going to love this dressing up bit. Time to get my order in before all this snow melts. Thanks one and all for some very interesting alternatives. One last question - would it be wise to inform the Police first of my intentions prior to someone calling in stating that they've seen green Aliens walking through the woods?
Tim L wrote on 1/7/2010, 2:22 PM
I would go with MSmart's version above.

Be sure to lock the exposure on your camera before you start shooting. Otherwise, the camera's autoexposure system will change the brightness of the snow as the person moves in and out of the shot.

Locking the exposure would also apply if you do the chromagreen alien version of the effect -- which I'd love to see but which I think will be difficult to do well. Don't forget that if it's a bright day the alien's shadows won't key out. But I'd still love to see the attempt... :-)
richard-amirault wrote on 1/7/2010, 5:49 PM
Don't forget that if it's a bright day the alien's shadows won't key out.

Yes, I forgot to mention ... if you do this do not do it on a sunny day, the shadows on the green person (say from the sun on one side) will not key out .. plus the shadow on the ground (but that might be a nice effect)

I would try this on an overcast day. That way you get a nice even lighting on the person.
MSmart wrote on 1/7/2010, 8:04 PM
I'm still liking my idea.
Eigentor wrote on 1/8/2010, 5:16 AM
"One last question - would it be wise to inform the Police first of my intentions prior to someone calling in stating that they've seen green Aliens walking through the woods? "

In Germany you're "Guilty till proven innocent", so yeah!
Also, don't dress like a bear.

Post your results. I'd love to see if I know what I'm talking about.