Exposure interactivity during rendering?

Corona Corona for 3ds Max Help Required
1

First of all congratulations to an amazing upgrade!

Second, simple beginner question. I’m using a physical camera so my frame buffer EV control is disabled. However, shouldn’t setting Render Setup / Post processing to Basic photographic settings allow me to adjust the exposure? Nothing happens when change these parameters? I’m in production rendering mode so I don’t have access to the actual camera.

2

Short version is: No because CameraMod overrides Physical Camera and Physical Camera overrides Render Settings. A similar thread is already here: Recommended way of setting exposure - Corona for 3ds Max :: Help Required - Chaos Forum

The whole camera/exposure stuff including a “live link” is some kind of confusing (and frequently discussed). It´s even possible that Camera settings will be completely removed from render settings to simplify things. Main problem is the live adjustment while rendering.

I wonder what would happen if it would work like this:

Render Settings (with override checkbox) > CameraMod > Physical Camera

This way it should be easy to have at least a live link from Render Settings to cVFB. Best of course would be to be able to have a link out of the scene camera (or/and CameraMod) to the frame buffer even while rendering production but I fear this would get hard to do and would not work anymore when Max is locked while rendering for some reason.

I´m really curious how this will evolve.

Good Luck

3

Thanks, at least I know then.

So am I understanding it correctly that, if I want to be able to adjust exposure during rendering, I can’t use physical cameras?

I agree, it is indeed confusing that choosing ‘Basic Photography Settings’ instead of ‘Tone Mapping/Use Simple Exposure’ actually changes the exposure in the frame buffer, but then you can’t adjust it.

4

You can, if

  • you choose “simple exposure” in the render settings
  • have no cCameraMod active, overriding EV
  • have not switched to EV/ISO in the physical cam (“Exposure” flyout)

As a result the complete “path” for simple exposure (EV) is “free” down/up the line

render settings (the winner regarding EV) < cCameraMod (no EV) < Physical Camera (no EV)

nothing overrides render settings then. Damn this is knotty.

And even more confusing: If you activate photographic as you described it and have not set the physical cam to EV, changing shutter and/or f-stop does nothing, but ISO still works because render settings “win” regarding ISO (which is not used by the physical cam in this case).

Good Luck

5

Thank you for the explanation. I have followed your instructions, but I have not gotten the expected result.
I am not using cCameraMod, just the physical camera. The EV spinner in the vfb still not working.
Does anybody have any suggestion for this issue?
I prefer to use physical camera due its possibilities for perspective control. I have tried with standard camera and CameraMod, but it is not the same.
Corona 1.5.

EV problem.jpg
EV problem.jpg994×307 34.1 KB

6

The third point is missing: Go to environment and effects (press “8”) and disable exposure control there.

Good Luck

7

Hi, please ad some light to me: when dou you use Simple Exposure and when use Photographic Exposure?

8

It is exactly the same thing in terms of image quality. You can create exactly the same image using both methods. Imagine the “Exposure” slider in Photoshop - you can just move it left or right and that’s pretty much what exposure does. The Simple and Photographic modes just control the EV slider using different parameters.

Photographic exposure is mostly useful if:

  • you want to reflect photographic settings of real life footage
  • you want to decide about the environment’s and scene lights’ intensity - for example you can set up your Corona Camera to some real life values (for example ISO 800, 1/30s, f4) and assume that this should give you a nice bright interior image and then adjust your environment and interior lighting to make sure your image is nice and bright

If you do not need photographic exposure for some specific reason, I would advise using simple exposure.