This shows you the differences between two versions of the page.
Both sides previous revision Previous revision | Previous revision | ||
rhino:rhinolensing [2016/05/13] |
rhino:rhinolensing [2020/09/24] (current) jb [Lens Questions] Added credit to Sam Page |
||
---|---|---|---|
Line 1: | Line 1: | ||
+ | ======Lens Questions====== | ||
+ | Written by Sam Page: https:// | ||
+ | =====What am I seeing when I assign a lens to a viewport? | ||
+ | |||
+ | When you assign a lens to a Rhino viewport using ViewportProperties, | ||
+ | |||
+ | =====Why do different sized cameras result in different angles of view with the same size lens?===== | ||
+ | |||
+ | Lens length is the distance from the focal node to the film plane. So with a 50mm lens, the focal node of the lens is, you guessed it, 50mm from the film plane. So with our standard Rhino viewport (and a SLR camera) the resulting view angle in plan view would be 39.6 degrees: | ||
+ | |||
+ | {{: | ||
+ | |||
+ | Now, if we pop that same 50mm lens onto a motion picture camera, the film plane size changes to 24mm (this format is called Super35): | ||
+ | |||
+ | {{: | ||
+ | |||
+ | So although you are keeping the same lens length, by changing your film size, you change your field of view. | ||
+ | |||
+ | =====So how do I get the view angle I want when using a " | ||
+ | |||
+ | There is now a script to do the heavy lifting for you: http:// | ||
+ | |||
+ | For the nitty gritty of what the script is doing, read below: | ||
+ | |||
+ | The first thing you need to do is to figure out the aspect ratio of your viewport. The easiest way to do this is to use the command ViewportProperties with a " | ||
+ | |||
+ | Now that you know your aspect ratio, you can figure out the film size that Rhino is showing you. Using our 1:1.67 aspect ratio, we know that the minimum aspect dimension in a Rhino viewport is always going to be 24mm, so the film size Rhino is showing me in a 1:1.67 viewport is 24mm by (24 * 1.67), or 24mm x 40mm. | ||
+ | |||
+ | So if you were trying to see what your view angle would be with a camera with a 3" x 5" film size (76mm x 127mm), you need to figure out what your crop multiplier is, the difference between Rhino' | ||
+ | |||
+ | Another example: You want to know what a 21mm lens looks like on a Super35 camera in 2.40:1 aspect. | ||
+ | |||
+ | Call ViewportProperties, | ||