When light hits the camera (exposure problem)

[dafassi]

Hi!
Im new in Blendigo and would need some help for a project.

There is an light-emitting (from texture) object, that shines through a glass.
The object is in space.

Now i have a problem with the ligthing:

When the camera is in a position, where the emitting object is visible, it seems indigo autocorrects the lighting... the background becomes darker.
When the emitting object is not visible the background becomes brighter.

I need a constant background.

Would you help me please?
I attached all files!

[StompinTom]

Sounds like a tonemapping problem. Check to make sure your tonemapping method is NOT set to Reinhard. Reinhard tonemapping automatically adjusts the 'exposure' of the image, which is problematic with high contrast scenes, especially between frames. Camera tonemapping solves this but requires you to tweak the exposure until it's balanced.

EDIT: Just took a look at your scene and your camera is set to Reinhard tonemapping (go Camera Properties > Indigo Tonemapping panel > Tonemapping Type)

[dafassi]

Thank you!
I´ve tryed that an earlyer moment and had the problem that everything is black.
What am i missing in my scene to make things visible using other tonemapping-methodes?

[dafassi]

Ive tryed a lot of combination.
It seems that it is not possible to have a HDRI-Background (visible, not just reflections) at the same time with other lighting-sources.
But- without other lighting sources it is not possible to use other tonemapping-options.

Camera - and linear mapping both need a light source - HDRI will not work for this mappings.
Reinhard is the only working thin- but gives me the autoexposure problem.

I also tryed to use light layers.
There is no way.

[StompinTom]

You just have to jack up the exposure (longer shutter speed, smaller f-stop, bump up the EV value, etc.) or increase light energy until you see your objects. Chances are your lights (or HDR background) is way too dim for your current camera settings. Either increase the exponent on your HDR hemi or increase your exposure in your camera settings.

[dafassi]

It sounds easy - would you please setup the scene for me?
As you can see i tryed many things and cant get it.
Im a photographer and know how the setup theoretical shoud be ... theoretical

Maybe the problem is that im using just the indigo-demo?

[StompinTom]

Here you go.

- Wordlamp Gain exponent to 9-10
- Tonemapping to Camera
- Rendering mode to Custom with Alpha Mask enabled so that you get a transparent background, meaning you can put whatever you want behind the logo.

[dafassi]

Allright, thank you!

With the ALPHA-method i dont need to change the tone-mapping .
Powering up the gain exponent of the world lamp did work- but gives me a far too bright background.

however- i need to render the background seperatly and composite it a later time.
The Alpha-method is the only problemsolver.
To bad! -1 for indigo!

Thank you StompinTom for helping!

[StompinTom]

You could put an emitting plane that fills the frame behind the logo with a lower emission value, that could let you tweak the background value as you like, though it's probably easier just to comp it in as a separate layer afterwards.

[dafassi]

Good idea .

One more question when using ALPHA-MASK-Output:

When i render frames with Alpha-Background the "IRIS" is black.
I cant see its color or emitting light.
Maybe indigo automaticly uses the PNG´s transparent layer in alphachanels?
How can i fix this?

Thanks