View Full Version : Syntheyes to LW

03 March 2005, 06:41 PM
Ive been tracking shots in Syntheyes and they look good. However when I export to LW the Focal Length of the camera is way to long. Any suggestions on what to do in Syntheyes? If not, does anyone know of any Syntheyes forums that get a lot of hits?


03 March 2005, 07:15 PM
There could be a number of reasons why it is too long and one major reason is because LW's focal length does not follow the norm of other 3d packages. Here are some solutions:

1. What focal length did u use in the initial match? Did you set this correctly in the match? Go to the camera's company's web-site and find out what the camera's focal length is when it is equivelent to a 35mm film camera. (For example, the Panasonic dvx100, its widest focal length is 4.5mm, which (according to its web-site) is equivelent to a 32.5mm film camera. So in order to convert the camera's focal length to use in Matchmover, I just multiplied the camera's focal length by 7.22222 ) So you might have to some converting.

2. LW's focal length might not match Syntheye's focal length. So you might have to do a conversion. Most other packages (Maya, Houdini) have equal focal lengths between them, meaning that a 35mm Maya focal length == 35mm Houdini focal length. However, LW's focal length does NOT match Maya's or Houdini's. The point is is that possibly Syntheye's exported focal length will fit the majority of package's other than LW. From a recent project that I worked out, we took Maya's and Houdini's focal length and multiplied it by 1.2 and that gave us our LW focal length. Though, This was @ a pixel aspect ratio of 1.2. If your pixel aspect ration is 1.0, then multiple your focal lenth by 1.19.

These are just possible solutions. Hopefully one of them will point you in the right direction.



03 March 2005, 07:39 PM
Thanks a lot man. Im still kinda noob'n my way around the program. I found out what lens the production used and entered that amount into Syntheyes. This seemed to help a lot. Half the time I dont know what Im doing but things still seem to work out.

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03 March 2005, 07:39 PM
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