# Calculating the Blender Camera to Match a real anamorphic Camera

So, I'm trying to model an object based on a film. I have several angles of the object from the film, but I'm trying to set up Blender's cameras to match the actual cameras used on set. I know that if I can determine the filmstock used, I can match up the 4 shots and get a relatively accurate representation.

I know the film was shot on 35mm film (not super 35) which has an image plane width of 21.95mm, but I also know that it was shot with anamorhic lenses giving the image a 2.35:1 aspect ratio.

So, here's the real question: If I want to match Blender's 3d cameras with the real ones, do I give the Blender camera sensor a width of 21.95mm or do I multiply it by 2, since it's using a 2x anamorphic lens, for a width of 43.90mm?

Edit #1 I was just thinking about it an in the Blender camera tracker there is the option to change the pixel aspect ratio. I just realized maybe if I add in the data (sensor width, and correct 2:1 pixel ratio) and track the shot, it may come up with the correct focal length, and when it puts the camera back into Blender, I can see what values it uses... but if anyone can give me any input in the mean time, (or in case that doesn't give me something useful) please feel free to share!

Edit #2 I tried this and the footage itself distorted out to 2x the 2.35:1 ratio, so now I guess I'll resqueez it so that Blender can then re-desqueeze it... rolls eyes

• Use the sensor size that matches the aperture used on the camera. Then use the aspect ratio 2:1 in the render settings and use the same lens size used on the shoot. Question for you: Is the footage you are trying to match squeezed or has it been unsqueezed and is using square pixels? – user1853 Sep 26 '17 at 0:43
• I guess I'll quit being secretive. I'm recreating Yoda's Hut from Empire Strikes Back for a short film. Progress here: blenderartists.org/forum/… – Blazer003 Sep 26 '17 at 17:07
• Whoops, I accidentally posted and it timed out my edit. Anyway, in order to get it as accurate as possible, I'm taking all the shots from the movie and trying to line up my geometry with each. So I have virtual cameras scattered around the model hut, but I'm having trouble getting some geometry to line up properly. I was using 21.95mm as the sensor size, then trying to match the focal length of the cameras to the shots, but this is where I was wondering if the sensor size should be 43.9mm since it was shot on anamorphics. – Blazer003 Sep 26 '17 at 17:15