Jump to content

Archived

This topic is now archived and is closed to further replies.

sxpeters

zoom in without distoring object?

Recommended Posts

  • Topic Author
  • Let's say I have my scene set up with all of my objects where I want them and my camera's focal set to where I want it and the output size set to what I need. But now I realize that I have a lot of unused space around my objects and it would be really nice if I could just zoom in with out changing the look of my scene or focal length, how can I do this? If I try and zoom in, leaving the focal length where it is, everything will start to distort.

    Thanks,

    Steve

    Share this post


    Link to post
    Share on other sites

    Guest dataflow

    render at different res ratio

    Share this post


    Link to post
    Share on other sites
  • Topic Author
  • Maybe I am not explaining myself well enough or maybe I am not understanding what your saying. Do you mean just render at a higher resolution? That would give me a bigger file but it's still going to be wasting pixels. I know that I could just crop out the un wanted area in PS, but I would think there should be an easier way to do this? I want to have my objects fill up as much of my scene as possible. Let say I need my image to be 1.6" x 1.2" @ 300dpi. So I put those dimension in the output set up, then I create my objects and set up my camera. Well now I realize that I have a lot of wasted space around my objects. Do I just have to do a render region?

    Thanks,

    Steve

    Share this post


    Link to post
    Share on other sites

    Is there some reason why you don't want to change the focal length? - that would be the way to do what you describe using a real camera.

    Mark

    Share this post


    Link to post
    Share on other sites
    Guest idigitize

    I think dataflow is the easiest answer.

    However, the longer the focal length, the more you will flatten perspective.

    The closer you move the camera toward the subject, you will widen perspective.

    So if you want to fill the frame, without changing perspective, you need to do a bit of both, not one or the other.

    Share this post


    Link to post
    Share on other sites
  • Topic Author
  • I was hoping that there was a way of doing it without having to tweak both the zoom and the focal length. I know that will do it, but I just thought there was a lot easier way. I see that 11.5 lets you render a region and also lets you do that based on your interactive render region. Basically that is what I was looking for.

    Share this post


    Link to post
    Share on other sites

    Uh? - a longer focal length doesn't flatten perspective, it just crops the view from where the camera is positioned. Zooming *is* changing the focal length - don't get it confused with dollying the camera in or out of the scene.

    Share this post


    Link to post
    Share on other sites
    Guest idigitize

    This might not help the original poster, but a longer focal length does flatten perspective.

    Please tell me thats true, or i wouldnt have bought a 300mm for my photography portraits? beg.gif lol

    http://www.photozone.de/focal-length-and-perspective

    Share this post


    Link to post
    Share on other sites

    I think the easiest way to see what your options are is to set up a new viewport where you can manipulate the camera while you watch the results. Dolly the camera in and out or grab the camera handles to adjust focal length and field of view simultaneously.

    Share this post


    Link to post
    Share on other sites

    This might not help the original poster, but a longer focal length does flatten perspective.

    Please tell me thats true, or i wouldnt have bought a 300mm for my photography portraits? beg.gif lol

    http://www.photozone.de/focal-length-and-perspective

    Sorry, but whoever wrote that article doesn't understand perspective.

    Perspective is a product of where you are in relation to what you're looking at, not what you're looking through. The further away you are, the flatter the perspective appears to be. So, what your 300mm lens is actually doing is to allow you to stand further away from your subject and still fill the frame. If you stood in the same spot with a 24mm lens and cropped the resulting image down to the coverage of the 300mm lens, the perspective in the image would be exactly the same.

    Mark

    Share this post


    Link to post
    Share on other sites

    This website (http://www.photozone...and-perspective) got me confused too!

    Lens distorsion is a real world artifact that doesn't exist in CG. So, using another focal length will zoom out or in like your view zooms in photoshop etc.

    Click to see the animated gif here:

    post-5516-125898926276_thumb.gif

    Share this post


    Link to post
    Share on other sites

    Here's a practical demonstration of what I was saying in my previous post.

    The set up is a fixed camera position and target. First image is with 50mm focal length. Second image is with 200mm focal length. Third image is cropped from the 50mm image and enlarged to the same frame size as the 200mm image ... bit blurry, but you should be able to see that the perspective is exactly the same.

    I'll also post the scene.

    Mark

    Share this post


    Link to post
    Share on other sites
    Guest
    This topic is now closed to further replies.

    • Recently Browsing   0 members

      No registered users viewing this page.

    ×
    ×
    • Create New...