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View Full Version : HD camera setup.... help please!

rbinny
06-16-2006, 04:34 PM
Hi

I'm just doing some previs work for a movie that is currently shooting. It's being shot on a HD Viper camera (1920x1080). I'm doing rough 3d extensions to things that have been shot and also assiting the production design dept by showing what certain sized sets would look like through certain lenses.... so they know how much to build.

The problem i've run into it that i have a basic shot in front of me (camera in front of a bit of flat set) i have the lens, the tilt, sizes of set, position of camera to set etc... - i have roughly modeled the piece of set, but the 3d and real set don't line up in C4D.... ug!

The only way i can get them to line up is by changing the aperture width - From what i understand the camera has a 2/3" CCD (which i believe is measured diagonally) which makes the actual aperture width 14.75mm - this ties in with when you load footage into Boujou and it says...HD footage...therefore the film back is 14.75x8.3mm.

Unfortunately the 14.75 doesn't line up and only changing to 9mm do things match.

If anyone can shed any light on this it would be much apprieciated.

Many Thanks

Robin
LemonNado
06-16-2006, 05:03 PM
You WANT this:

http://www.vreel-3d.de/plugins/PhotoMatch/links.html

Excellent for callibration... Now even with a lens shader for distortions.

Mega cool and mega cheap for what it does!

Rainer
rbinny
06-16-2006, 05:08 PM
thanks - i'll certainly give it a try.
LemonNado
06-16-2006, 06:06 PM
Check out the intro videos they have. They are showing nicely what you can do. Set extension should be a breeze. For tracking, in case you need that one day, I can recommend syntheyes.

cheers
rainer
lightdog
06-16-2006, 08:47 PM
For a project using a Panavision/SONY Cinealta HD camera, I used 9.601 for the aperture width. If memory serves, this value is calculated from the actual imaging area for the chip, not just from the 2/3" spec. I can dig up some more info, if anyone is interested.
rbinny
06-16-2006, 11:05 PM
9.6 certainly sounds more along the lines of the result i was getting. Having less active area than the 2/3" would make sense but as yet have found no one to tell me what that number is....if you can give some more info on what you discovered that would be great!

Many Thanks

Robin
lightdog
06-22-2006, 01:23 AM
I did a quick search at

www.viperfilmstreamcamera.com/

and the relevant docs do not list anything other than the 2/3" spec. for the chip. Wikipedia

http://en.wikipedia.org/wiki/Digital_cinematography

has some comparison info and suggests that the chip specs are similar to other HD cameras (in terms of dimensions), but a call to

http://www.thomsongrassvalley.com/products/cameras/viper/

might yield further answers...
rbinny
06-22-2006, 08:00 AM
Thanks mainly to the nice people at 2d3 (makers of Boujou) i think my problem is now solved -

"....2/3" doesn't actually mean 2/3"! It's a
description of the 'type' of CCD rather than an actual dimension. The
physical size of the sensor is 8.8mm wide by 6.6mm high, and these are
the numbers that you should use as your filmback"

also intersting other info...

http://www.cinematography.net/HD%20TOC.htm

and also this is about digital stills camera i think it's still along the right lines

http://www.dpreview.com/learn/?/Glossary/Camera_System/Sensor_Sizes_01.htm


cheers

robin
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06-22-2006, 08:00 AM
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