Lens tilt/swing?

[zaar]

Hi!

I suspect this is way too niche and also something that will fly over most heads.
But I wonder if someone with insight into writing a ray/pathtracer (preferably a developer of corona ;) ) could answer if it would be possible to implement lens tilt/swing in order to change the angle of the focus plane according to the scheimpflug principle?

Doing product shots in Corona, I use a lot of lens shift to obtain desired perspectives/projections - as one would do in a real studio. And it would be cool if I could have all the tools of a physical camera in corona too.

Using tilt/swing in real life is really really hard. But having focus plane preview on the corona cam, it would be a nice tool to have up my sleave.


</ weird question that probably doesn't deserve much attention in the grand scheme of developing corona render>

[maru]

(Not a developer here)
Camera tilt and shift does affect the focal plane. Can you explain what exactly is missing?

[zaar]

Yes, but it also affect the geometry/projection. Tilt on my real tilt-shift lens does affect the projection a bit, but the focus plane more. And with a ray tracer maybe one could separate the angle of the dot plane completely from the geometric projection?
Tilt in the corona can is more like “camera tilt correction” too me. And I just want to tilt the front lens.

With reservations for me hallucinating all of this :) wil try if I can get a nice result with corona cam tilt, maybe one can counteract the geometric affect with shift.

[maru]

I am sorry, but I still don't understand what you mean. Maybe an example of what you are getting in real life vs Corona would help.

[zaar]

This is a fairly good example of how tilt/swing works.
https://www.westechoptical.com/blog/the-scheimpflug-principle

It’s hard to explain what I want to do without making a diagram. But it’s basically a diagonal shot across a product and the plane of focus is also diagonal across the product, but I would like the plane of focus to be more in the local orientation of the product. Unlike the train track example on the link, I don’t want to use the effect tot get longer or shorter perceived dof, I still want it to be short, only hitting the right details on the product.

[burnin]

I too would like 'squashed perspective distortion' (which  means image isn't in 1:1 pixel aspect ratio). Since I have same problem ~ can't mimic anamorphic film format technique, because of Corona's inability to handle/manipulate pixel aspect ratio (C4D feature isn't supported).
Only way is to do it 'physically' (model lenses/simulate RL) which is quite PITA using Corona.

[zaar]

Not sure if this is the same thing. But definitely interesting as a topic of discussion. And definitely an edge case for arch-viz first Corona.
What characteristic of an anamorphic lens do you want to mimic? Is it just how out of focus highlights look or the whole thing like how funky a focus pull looks?

[burnin]

Yup, ain't exactly the same, but same feature could resolve both problems.

Otherwise, I wish to be able to mimic the whole 'camera look' which I don't think it's such a niche (touch/action' (application), especially for photo-real rendering. The thing is, artists have no tools to do it effortlessly. ;) And from all engines I used or tried, only Corona lacks in this regard.