Expand camera's frame problem

[flood]

I want to expand camera's frame without changing the view or fov. And I want to do it without the need to change the render width and height output size.

The output size is set and wouldn't want to change it. But I need a wider view without changing how everything looks FOV wise.

Is there a way with Corona Camera?

[pokoy]

Obviously, you'll need to change frame size since you want to add some fov on all sides, correct?

Here's a script that works with the Standard Camera, you can then use the same values for CoronaCam, make sure to use the same sensor/back size in the renderer general setting as in your CoronaCam:
http://scripts.breidt.net/#overscan

[flood]

Well, i'm rendering at 1920x1080 . So I want to keep the same amout of pixels but would like to have more view without changing the fov.

I don't know if the script will do that, but will check it out

[PROH]

Hmm.... If I understand you correct, you wasnt to see more without changing aspect ratio and FOV. This is done by moving your camera further away from your objects (by the cameras local z-axis).

[flood]

Hmm.... If I understand you correct, you wasnt to see more without changing aspect ratio and FOV. This is done by moving your camera further away from your objects (by the cameras local z-axis).

Thanks for replying.

When just changing the camera using the Z-axis, the fov doesn't change but because of perspective the image is a little different. It's hard to explain without images.

[PROH]

Yes the view will change - just as it will with "a wider view". How can you see more without changing anything?

[flood]

Yes the view will change - just as it will with "a wider view". How can you see more without changing anything?

That was my question. Can I render more of the image without changing the perspective. Theoratically it's possible. There is a workaround but I don't like it.
I would need to change the output size and then rescale the image in photoshop or something.

[TomG]

I don't fully grasp what you want to do here - just like the real world, to fit more into your image, you need to either a) move the camera back or b) change the focal length of your lens for a wider field of view. Both are possible in Corona, just as they are with a real camera.

The final image resolution is unrelated to what you see in the image (both with Corona, and with a camera) so changing the output size would make no difference to what you can see in the image, it just makes the whole image larger (or smaller - same as scaling a photograph once you've taken it). And again with both, changing how much of a scene is shown in the image will change the size and positions of things in that image (your chair is going to be smaller now, and in a different place, because the image has a wider field of view and the chair occupies a smaller percentage of that).

[flood]

I don't fully grasp what you want to do here - just like the real world, to fit more into your image, you need to either a) move the camera back or b) change the focal length of your lens for a wider field of view. Both are possible in Corona, just as they are with a real camera.

The final image resolution is unrelated to what you see in the image (both with Corona, and with a camera) so changing the output size would make no difference to what you can see in the image, it just makes the whole image larger (or smaller - same as scaling a photograph once you've taken it). And again with both, changing how much of a scene is shown in the image will change the size and positions of things in that image (your chair is going to be smaller now, and in a different place, because the image has a wider field of view and the chair occupies a smaller percentage of that).

To make it more clear , i want to do this :   (but without changing the size of the image).
 http://www.peterguthrie.net/blog/2013/01/overscan

I would accomplish what I want by resizing the image back to the original size in photoshop (but i would like to see if there is another way).

[TomG]

I don't think there would be another way - the tip there is indeed changing the focal length of the virtual lens (just as you would with a real world lens). As far as I can see, you wouldn't need to then render to this new resolution, you could just use the old unchanged resolution and only use this formula for working out how the focal length needs to change to add "that much extra" to the field of view. The size of the final image doesn't affect how much you see in your scene, so it wouldn't matter which size you rendered to.

[flood]

Thanks for explaining this TomG.

[TomG]

No worries! In the case of Peter's solution, the formula is to work out the percentage to change the focal length by in order to add that many specific extra pixels, but you can skip that and just adjust the focal length based on a percentage change without altering the actual render resolution (or go with the formula in that post if you want to make it "as if" you had added an extra 400 pixels, but again you can still render to the same resolution). But without worrying about pixels, you could just multiply the focal length by 0.75 (or some other value) anyway without worrying about pixels - you should be able to use IR to settle on just how much change to the focal length you want.