Author Topic: Shift lens in corona camera  (Read 1656 times)

2023-12-11, 17:30:22

rafalpen

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Hi, I bought a corona renderer a few weeks ago. This is a very professional product. But... there are some problems.  Exactly about the corona camera. I haven't found parameters such as vertical and horizontal shift anywhere ( not offset x and y). This is very important when I work on a composition!!! I worked on version 3.7 for several years. and these parameters give me a view like through a professional lens. I was able to fix the image right away in the camera rather than fixing it later in Photoshop. It works like shift lens in analog camera. I don't know why the crown doesn't have such an important function!!! Look, I can straighten a vertical line when the camera rotates through a vertical angle other than 0 degrees. I attach few jpg  who show how works shift correction in vray 3.7. someone can repair the camera

2023-12-11, 20:59:06
Reply #1

davetwo

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I know it's hard to break your established workflow. And I guess if you need to rebuild and match scenes already set up in V-ray this may be a pain. But Corona doesn't have this, and I've never needed it personally.

Just keep your camera straight and use a combination of camera positon and Y offset to get the same result.

2023-12-12, 14:26:20
Reply #2

James Vella

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Strange since that option is available in the Corona Camera in 3dsmax, is it a C4D implementation limitation?

2023-12-12, 15:00:07
Reply #3

John_Do

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Hi,

Corona use the settings from the Cinema 4D builtin camera


2023-12-20, 11:06:52
Reply #4

rafalpen

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Shift it isn't the same like offset

2023-12-20, 11:12:56
Reply #5

rafalpen

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James Vella doesn't have this in c4d

2023-12-20, 11:25:51
Reply #6

John_Do

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Sure, but unless you're looking for result in #3, the one in #2 can be replicated with Offset.

What you're asking for is the Tilt parameter in Corona for Max, and it is not implemented in C4D.
It seems there was an Xpresso tilt-shift camera rig in the old content browser, but I can't find it in the current Asset Browser.

2023-12-20, 11:32:12
Reply #7

John_Do

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That "Automatic Vertical Tilt" in 3ds Max is convenient !

It can be easily replicated in C4D with a Protection Tag (scene attached) :




2023-12-20, 12:18:33
Reply #8

Stefan-L

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"Shift it isn't the same like offset"

well shift is exactly offset.
(what you probably mean is tilting).

shift offsets the lens in regard to the film sensor. most pro shift lenses work like this.
tilt  changes the angle between lens axis and photo sensor. this results in a distortion which can be used to get vertical parallel lines too visually), this is what max uses.

actually shift is usually seen as the better as it doesn't distort the image but keep all lines natural, like in real world and expensive shift lens, used by architectural photographers. on ekeeps the camera horizontal and adjust the view via the shift(offset) value.
(not all in max is better)

i recommend using the c4d offset which is the best and closest to real world shift lenses way to keep vertical lines parallel.
« Last Edit: 2023-12-20, 12:47:06 by Stefan-L »

2023-12-20, 17:28:42
Reply #9

Pepelecrabb

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http://www.trenholm.org/hmmerk/VuCamTxt.pdf!

Since we have unlimited DOF in 3D this subject pertains primarily to controlling shallow focus DOF but also helps with distortion.  In C4D, adjusting rotation of the camera (Swing or Tilt) and then adjusting Offset (Shift) is essentially rotating the Film/Sensor Plane and keeping the Lens Plane perpendicular to it. You do not need the Protection Tag. It would be beneficial to be able to rotate the lens plane separate from the Camera/Film/Sensor Plane. Rotating any of these Planes changes the shape of the Subject Plane, so ideally all three planes should be rotated for less distortion and optimum focus. In the real world, the subject is often fixed so we only have the other two planes to adjust which is helpful but limited. In C4D, only the Film/Sensor/Camera Plane can be rotated which is helpful but more limited. On the plus side, we have unlimited DOF and X/Y Offset!

Here are some examples of how rotating the camera changes DOF and Subject Shape. The fstop(f2) and Focal Length (90mm) and Sensor Size (52.5) remain the same. The more Rotation (Tilt) and Offset (Shift) applied the more the camera needs to be pulled back to include the same subject area which also affects the amount of DOF. Sorry these down and dirty examples do not show the difference in focus very well. I should have placed the cylinders on a textured or otherwise detailed surface to show the DOF falloff better. On the full tilt example the surface is out of focus and only the tops of the cylinders are sharp.