Setting a "distant" camera perspective?

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Setting a "distant" camera perspective?

Is there a way to set a "distant" perspective in rendering an object? I'm trying to create some large objects but with a "distant" perspective. If I zoom in to an object to make it fill the camera view, it's obvious I'm close to it because of the perspective. And if I enlarge a distant image after rendering, it's grainy. I'm hoping there's a hidden "use distant perspective in render" button somewhere. Setting the canvas to something huge and then backing away from the object doesn't help all that much.
 

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Hey,
You might want to play aroud with the field of veiw setting on the camera. Click the camera in the object browser and just change the settings on the field of view.

Greg

>Oh sorry didn't see you post Francois.
 
Hi.
There´s a brand new feature in 4.3.1. Once you found your camera angle (works also in perspective and all other views) hold down shift and zoom in or out via scroll mouse button. Very intuitiv and fast.

With kindest regards
Frank
 
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The shift-scrollwheel will only work if you set the mousepreferences to the Maya setting. If you use the onebutton setting it won't work (yet?).

Regards,

Peter
 
On topic I think. What does the field of view actually represent? Is it related to a camera lens e.g. field of view 35 equals 35mm lens? I know what it does I would like to know if it relates to a physical camera lens.
 
It relates to focal length in a camera lens, but bear in mind that the distortion of an image through 3d rendering is not exactly the same as that through camera lenses (which in fact varies from lens to lens).

It's really about time folks stopped using "mm" of focal length to describe camera lens and switched to degrees of field of view. I don't think we'll ever go back to most cameras being 35mm, even if full frame 35mm sensors become really cheap, most folks will opt for a tiny camera over one which produces a ridiculously good image.

In 35mm (film/sensor) terms a 50mm lens produces perspective effects analogous to the human eye. (Note that a human eye has rather more field of view.) Traditionally, "wide angle" lenses with little or no distortion start at ~24mm (28mm being more common). "Fish eye" lenses start at ~6mm.

If you look at the diagram attached (High School optics!) you'll see that the lens's focal length determines the field of view.

(Note that actual focal lengths for camera lenses in no way resemble the stated focal length -- a series of lenses is used to capture as much light as possible, reduce distortion, minimize chromatic abberation, and focus the image on the focal plane at the distance required to fit the lens into the space available. The "focal length" of a lens is the focal length of that lens were it a single element.)
 

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It relates to focal length in a camera lens, but bear in mind that the distortion of an image through 3d rendering is not exactly the same as that through camera lenses (which in fact varies from lens to lens).
Click to expand...

Thanks for the reply, I'm not sure I fully grasp it but I'll read it a few times and look some things up.

Which brings up another question. Why is the distortion so strange in 3D?
 
It's not so much strange as different.

Your eye focuses onto a sensor that's shaped like the inside of a sphere. For obvious reasons this creates a different projection of the world than a film camera (even one with a perfect lens).

For images which are cropped to a very small field of view, the two projections are approximately the same, but once you "zoom out" the differences become apparent. The simple example is vertical straight lines -- like pillars, walls, etc. If you think about it for a second, you'll realise that a correct perspective rendering of a tall straight line offset from the center of your field of view onto a flat surface will be curved, but in a 3d program it won't be (unless it is using sophisticated algorithms to match camera projections).

Bear in mind -- there is no "true" 3d projection. All of these things are arbitrary representations of a 3d scene on a 2d surface. Your brain just happens to be most comfortable with the projection made by the lenses in your eyes onto your retinas.

And finally, your eyes aren't as good as you think they are. Imagine you hold a ruler up to the edge of a building to check if the edge is "straight". Now, of course, the ruler is being distorted the same way the building is, so that's not much help. But, what's more, when you look at it, you can't really check out of your peripheral vision ... without thinking about it, your eye will center the thing you're interested in, completely obviating the test.

This is why it took artists so long to understand lighting and depth of field. When you look at a "scene" you actually flick your eyes all over the place and they adjust focus and exposure automatically. Your brain assembles all this into a single, "correctly exposed" image which no camera or 3d program can, naively, recreate.
 

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I believe some high end 3d tools have the ability not only to produce camera-like perspective, but the ability to reproduce distortion based on settings tied to specific lenses.

Lightwave 3D 9 introduced Advanced Camera Tools specifically to do this.

ElectricImage, I believe has had it for some time (but I could be wrong -- it may have been a third party plugin).

I'm pretty sure all the high end tools have it either as standard or via third party plugins.

Adobe Photoshop has tools for correcting camera lens distortion (again, you can specify a lens profile). I would imagine that After Effects (and possibly Premiere) also support this...

You can achieve the results (crudely) by using the Fisheye filter in Final Cut Pro (with a slight positive value).

Here's a link to a demo of Photomatch 3.1 -- a third party tool for matching lens perspective in Cinema 4D:

http://www.vreel-3d.de/plugins/PhotoMatch/v3/LensDistortion_lo.mov
 
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