Any tutorial I have seen use oval shape to add vignette effect.
Why?
Vignette is result of circular lens, so why everybody are creating oval vignette shape in their renders?
Its not about lens or real world, its about framing.
If using the compositor projector node then its because of the ‘fit’ stretch that happens with scene dimensions. But I agree with you. However vignetting can come from other lens elements than just the lens barrel.
I have seen hoods and flare mattes produce rounded squares as well.
@Wakka: I don’t think so, people it presenting as camera artefact
@3pointEdirt: yes, it can come from other things,
I just haven’t seen it oval. Only done in postpro.
And people use oval as something common, like you know… Vignetting
Doesn’t it happen due to anamorphic capture, widescreen footage recorded on 4:3 film?
I think the visual presentation is more of a matter of biomechanics than representing any kind of camera presentation. The way we see things is effectively oval shaped (wider left-right), with loss of detail and color towards the edges. The effect is more apparent when remembering what we’ve seen. So presenting an image that way on screen is a more-or-less subtle prompt instructing the viewers brain “Remember when…”.
@TiagoTiago: yes, but also anamorphic does oval in a bit different way.
http://www.red.com/learn/red-101/anamorphic-lenses
@dgorsman: sorry, probably I wasn’t clear enough, but I don’t speak about highlighting centre of image for observer’s better focus reason. I speak about blender users, that are trying recreate real cam artefacts on their renders.
I’m not very well versed on cameras, so maybe this is a stupid question, but the image of the real anamorphic lens applies to a Full HD resolution (1920x1080) or a 2:35 resolution (1920x817)?
Anamorphic squeeze is 2:1 ratio so the vignetting should have the same aspect. What the filmback/sensor aspect and resolution are is another thing not related to anamorphic lens directly. The resolution of digital cinema 2K cinemascope is 2048x858 px.
To be honest I think folks use vignette to usually just add some gradient to flat lighting. Technically, yeah, the vignette is usually round.