Shooting Laser light

[James Buck]

Has anyone used Red to shoot a laser light? ive got a shoot coming up where we want to shoot the 'beam' making a pattern on a surface at 100fps +. I can't think of any potential problems but was wondering if anyone had shot anything similar to this?
many thanks. James B. D.O.P

 

[Wayne D]

http://reduser.net/forum/showthread.php?t=16174&highlight=shooting+lasers
hope this is of some help

 

[NateWeaver]

I've seen a clip from a Sony F350 XDCAM where they were shooting some sort of laser skin treatment. It was short "zap" style discharges, shot from over 10 feet away as the wide shot.

After each zap, you could see a faint purple burn stay in the image, so after 5 zaps, there were 5 faint, but objectionable purple burns on the image.

BTW, I found this on the Sony service FTP site as an MXF clip somebody had uploaded to service!

I'd like to know how one can figure out whether a laser is going to be safe to shoot or not.

 

[Peter Versey]

I shot lasers and mixed slide projections on 35mm many years ago.
To see a consistent beam you need settled non swirling smoke and balance the smoke density with the brightness of the pattern formed by the laser. too thick you loose the screen pattern, too thin and the beam is weak.
Do you need 100fps ... you could slow the pattern speed of the laser and shoot 25fps. and see what you're getting realtime.
the important thing is to have the pattern completed each frame exposed or it will jump back & forth or travel (you might like that)
Lasers can be V dangerous for the eyes make sure you make everybody safe take your watch off they reflect lasers everywhere.

 

[Robert Berger]

I shot lasers and mixed slide projections on 35mm many years ago.
To see a consistent beam you need settled non swirling smoke and balance the smoke density with the brightness of the pattern formed by the laser. too thick you loose the screen pattern, too thin and the beam is weak.
Do you need 100fps ... you could slow the pattern speed of the laser and shoot 25fps. and see what you're getting realtime.
the important thing is to have the pattern completed each frame exposed or it will jump back & forth or travel (you might like that)
Lasers can be V dangerous for the eyes make sure you make everybody safe take your watch off they reflect lasers everywhere.

Not only bad for your eyes, it will kill your pixels of your sensor when it hits directly the lens if the laser is power full. A camera destroit by shooting a laser show what normaly was high above people in a discotheek. Camera was in a to high position and catcht the laser bean directly.

Robert

 

[Matthew Greene]

at 100 fps you're going to get some serious flicker too, LASERS, when they're drawing an image or pattern, they usually do so by usually moving the same tiny point or beam very quickly to create a shape.

I shoot (and use in theatre) LASERS quite often, you want to go as low as you can with framerate and as open as you can with the shutter speed to reduce flickering effects. He're's an example of a LASER shot on film 24fps with either a 180 or 220 degree shutter. (The laser would be a perfectly round cone, the black areas are the shadow of the talent breaking the beam by flying into the cone in mid-air.)

Had this LASER tunnel been shot with a narrower shutter or higher speed you'd only see part of the cone being drawn on each frame. Like here (Shot on video 1/60 shutter):

I've never shot a high powered LASER into my RED camera (or any camera except for film). I say avoid it, just like you avoid looking into a LASER

 

[James Buck]

Shooting lasers

Shooting lasers

Thanks for getting back to me everyone.

After a day of testing on the red we ended wanting to do a shot going from outside the 'cone' of the laser to the inside whilst looking at the centre point. This was obviously was not going to be good news for the sensor on the red so we ended up going onto 35mm. For the record we slowed the rate of the laser to as slow as possible and shot a 4 F.P.S on a motion control rig.

All the best

James Buck

D.O.P / London.