The Carrara Camera

gregoryhilldesign

I have a question about the camera (specifically the conical camera) function in Carrara.

I'm doing more and more 3D modeling for the films I work on, which is great for my concept work. However, on my current film the production designer is getting me involved in doing some previz work. This is also great, since it seems nobody here in NY does that.

The problem is that previz is usually done using Maya where there are a selection of "real world" cameras to choose from in rendering the scenes. It's usually done to pre-visualize action scenes, set camera angles, and pre-determine how built sets merge with digital set extensions.
Generally, the previz is created using the digital version of the real camera the DP will use, and has lens info, and all that. I've never had to get that technical before.

The Visual Effects supervisor (who had never heard of Carrara... no surprise there) asked what cameras were built in, and I told him that there is just the one. I found in the Carrara guide that the camera simulates a 35 mm still camera. In movie terms that means Vistavision. Does anyone have any experience with using Carrara for previz and how the camera relates to other motion picture film formats (anamorphic, etc.)?

Thanks
Gregory Hill

thoromyr

That's an interesting question and... I'm not who you directed it at, but some checking turned up the following. It appears that Maya's camera definitions consist of a name, sensor width and height, and focal length. The width and height are used to generate aspect ratio (and perhaps the resolution?) while the focal length is of course the focal length.

The carrara camera settings allow controlling the focal length from 6 mm to 500 mm in increments of 1 mm. The width and height are characteristics of the render settings, output tab, Image Size (though IMO it would be much handier if they were moved to the camera). There is also a "Distance to near plane" setting which controls how close an object can be to the camera and still be resolved.

So... within those limitations you should be able to set the carrara camera appropriately. It appears that you can convert other sensor sizes to an equivalent 35mm which should allow you to reproduce arbitrary cameras in carrara by using an appropriate mix of camera and render settings.

Of course, getting the appropriate information to replicate a particular camera is another matter.

References
Maya Camera Preset Information
Focal Length and link to conversion

Milo

Once you get the Camera's saved you can save them as a Scene Preset by dragging the Camera to the Scene tab (setting up your own folder first). You could also save a scene with no lights and just several cameras for a quick start.

Though that might be interesting to develop a set of Camera presets for just this reason, then everyone could drag away with all the proper names etc.

thoromyr

Daz is a bit behind in notifications -- i just got the email for this thread...

That's a good tip about storing camera presets, if I'd known you could do that I'd forgotten.

However, because Carrara doesn't allow all the information to be stored in the camera (e.g., resolution/display ratio) I recommend that if saving them as presets to include that in the name. Though I haven't had any reason to use camera presets I have used multiple cameras in a scene, one positioned for a 4:3 shot, another for 16:9. I find it helpful to have the ratio in the name for sanity checking when selecting a camera and setting resolution in the render room.

wetcircuit

A quick google for "lens mm calculator" gave me this site:
http://www.digified.net/focallength/
among others...