Focal lenses and image distortion in cinema

[Petr Kvapil]

Is it true that it is better to watch films shot with wide lenses (for example Terry Gilliam movies) in the cinema from the front rows and films shot with long lenses (for example Ridley Scott movies) from the back rows, otherwise the image is slightly distorted? I read that in a book once, but I can't remember where.

[Abdul Rahman Jamous]

No, it's not true

[David Mullen ASC]

If the image is distorted in a Terry Gilliam movie, it's on purpose.

[Petr Kvapil]

I wish I could find that book. It was very technical. it said something about perspective and that film projector lenses have a certain focal length because the most common lens for film is 50mm, but that it also depends on what lenses the film was shot with and how far away from the screen the viewer is sitting in the cinema. Maybe I'm describing it wrong, but I remember being quite surprised by that information.

[Mark Dunn]

Were you to follow that advice you'd be tending to exaggerate the effect that the film-maker intended. There can be a bit of a wide-angle effect when you sit close to the screen, but if it's too pronounced I'd say the seats had been put too close.

The projector lens can't have any influence on the perspective in the scene. The focal length is chosen to fill the screen at the prescribed distance, nothing more.

Edited July 27, 2023 by Mark Dunn

[Petr Kvapil]

I found the book. It is called Anton Wilson's Cinema Workshop. You can find it on Google Books or in Internet archive. The information is on page 99 about Lens Perspective.

[Petr Kvapil]

Here is the book:

https://www.google.com/books/edition/Anton_Wilson_s_Cinema_Workshop/18Ck5PZX_ZsC?hl=cs&gbpv=1&dq=cinema+workshop+lens+perspective&pg=PA99&printsec=frontcover

https://archive.org/details/antonwilsonscine0000wils/page/98/mode/2up

[Petr Kvapil]

1 hour ago, David Mullen ASC said:

If the image is distorted in a Terry Gilliam movie, it's on purpose.

Sure. I mentioned him only as an example of a director who uses mostly wide lenses.

[Kyryll Sobolev]

i feel like for most cinema viewers, the brain compensates for any possible centre of perspective changes much the same way that it adjusts the "white balance" of the eyes

sure at some extreme angles and distances a shot may look weird on a giant screen. but the movie theatre by design cannot have an ideal viewing perspective for everyone

[David Mullen ASC]

The author of the book is NOT suggesting that you are supposed to counteract the effect of the camera's focal length by changing seating position in the theater.

What he is saying is a bit reductive and not completely accurate but there is some rough truth in there.

But it's more practical when you are talking about very large theater screens showing a very high resolution image. IMAX is a good example, the screen is larger than normal compared to the center viewing distance in order for the image to expand into your peripheral vision. Cinerama was similar except that the image was only expanded on the horizontal axis.  The idea is that with a very large and sharp image, sharp enough to look sharp though enlarged, you were concentrating on the center of the screen and letting some information "tickle" your peripheral vision to make the experience more immersive.

IMAX often tends to use very wide-angle lenses because when you sat in the center or slightly forward of center, you were concentrating on a more "normal" focal-length area. Cinerama was similar, the fixed field of view was very wide.  With either format, if you sat at the back of the theater or looked at the movie on a TV screen, you were more aware of the wide-angle photography.

But in a normal 35mm movie, if a director chose wide-angle lenses, it was for an effect or for the expanded view, it was not because they wanted you to get up out of your seat and move closer to get back to a more normal view because you were concentrating only on the center of the screen.

Frame from "How the West Was Won" (3-panel Cinerama), in the Smilevision letterbox format to replicate the look on a curved screen.

[Petr Kvapil]

Thank you for the explanation. By the way, I recently saw Oppenheimer at IMAX in Prague, where it was screened in 70 mm. Unfortunately, I was sitting very close to the screen in the third row and not quite in the middle and the image on the screen was very distorted (especially in the closeups of the faces). I understand that the high height of the (panoramic) screen is mainly to blame, but it was a pretty jarring experience. I didn't get used to it until about halfway through the film.