Vignetting adjustments right in the VFB

[Alex_M]

I know this is out of scope for version 3.5 but are there any plans for an interactive vignetting adjustment right in the VFB? A small feature but sometimes a nice vignette effect can make all the difference in the image. It can be another slider in the CC panel. What about an additional adjustment for the softness/hardness of the "edge" of the vignetting effect? So one can make the vignette transition more gradual or have it more abrupt.

[Dave_Wortley]

I'd like to see this as a lens effect rather than an in-render camera property.

[vlado]

I know this is out of scope for version 3.5 but are there any plans for an interactive vignetting adjustment right in the VFB?

Technically vignetting is a render-time effect related to the DOF and if it is done as a post-effect, it won't be quite correct. It also has a physical meaning and artistic adjustments would not he physically accurate. I do realize that probably nobody cares about any of this though

Best regards,
Vlado

[Alex_M]

Ok, let's leave the size/spread of vignetting aside as it does depend on the camera lens settings. What if we just want to turn it on or off on the fly while rendering and also maybe adjust the opacity? Won't break any physical laws but at least you won't have to rerender just to add or remove this effect.

[Dave_Wortley]

Technically vignetting is a render-time effect related to the DOF and if it is done as a post-effect, it won't be quite correct. It also has a physical meaning and artistic adjustments would not he physically accurate. I do realize that probably nobody cares about any of this though

Best regards,
Vlado

Well it's linked to the aperture not the DOF and it's very lens dependent, happening more on a zoomed lens at its maximum zoom, but then you could have a prime lens at the same focal and aperture and it not vignette so badly. So it almost becomes an artistic choice as a good lens profiler will almost completely remove it. In my own photography I often add vignetting artistically, and not always circularly. Gradient NDs are often needed in photography, that'd be something that would be better as a lens effect.

For those that want more technical information, looking at the DXO Mark charts you can see how vignetting changes on different lenses.

@Vlado - Does the DOF Bokeh become more elliptical towards the edges of the image too with a wide aperture? or does it stay round

[Dave_Wortley]

Oh and now you've got all these Scanned Materials, have you thought any more about my hypothetical question of could we have polarising filters in VRay to mimic effects that we have in real-life like when shooting a car and we want to tone down the reflection?

[vlado]

Oh and now you've got all these Scanned Materials, have you thought any more about my hypothetical question of could we have polarising filters in VRay

Yes, we thought about it, but we have not reached any specific conclusion

Best regards,
Vlado

[Dave_Wortley]

Yes, we thought about it, but we have not reached any specific conclusion

Best regards,
Vlado

Sounds like a good topic for a Siggraph Paper

[Alan Iglesias]

...I do realize that probably nobody cares about any of this though

HA! Hilarious - you kill me Vlado.

DaveW makes very good points here. How about we have two Vignette systems - one the physical one in the camera and an "artistic" one in the VFB?

More tools, more fun!

-Alan