Anamorphic and VFX?

Joe Giambrone · November 3, 2009

Here's the situation. Compositing a green-screened miniature that's blown up 12-15x onto a landscape (say: the squirrel that ate Manhattan).

I'd like the bulk of the film (the landscape) to be shot on anamorphic. Does this make it impossible to pull off the composition?

Some advice suggested the miniature should be a shot on a very short 10mm or so lens in order to get enough DOF to keep the miniature in focus. Are there anamorphic lenses that short?

Can some miniature elements be shot with spherical lenses, or will this pop out like a sore thumb and blow the whole effect?

David Mullen ASC · November 3, 2009

Here's the situation. Compositing a green-screened miniature that's blown up 12-15x onto a landscape (say: the squirrel that ate Manhattan).

I'd like the bulk of the film (the landscape) to be shot on anamorphic. Does this make it impossible to pull off the composition?

Some advice suggested the miniature should be a shot on a very short 10mm or so lens in order to get enough DOF to keep the miniature in focus. Are there anamorphic lenses that short?

Can some miniature elements be shot with spherical lenses, or will this pop out like a sore thumb and blow the whole effect?

It's not unusual for 4-perf 35mm anamorphic features to have efx elements shot in VistaVision (8-perf 35mm) or 5-perf 65mm, which are spherical formats, for many reasons -- one is that it's better and easier to shoot miniatures with spherical lenses.

Also, miniatures are often used for, in effect, "wide shots" in movies -- and in an anamorphic movie, wide shots often do not show anamorphic artifacts anyway (except for lens flares) because the focus is naturally set in the distance. Anamorphic bokeh is more obvious in close-ups with an out of focus background. So for miniature work that is meant to look like a large object in the distance, you actually don't want to see anamorphic bokeh, you'd want a deep-focus shot. So it makes sense to shoot those elements with spherical lenses stopped down for a lot of depth of field.

A few anamorphic movies have even gone so far as to shoot the efx in ordinary Super-35, not VistaVision -- such as "Lost in Space" -- though the problem starts to be that in this case, the anamorphic photography is finer-grained than the Super-35 efx because it uses more negative for a 2.40 image. If you are shooting digitally, however, this is less of an issue. For a digital movie shot in anamorphic, switching to spherical lenses for miniature efx work makes sense.

In fact, the majority of anamorphic movies have efx elements shot with spherical lenses -- "Star Wars" for example. The grey area becomes live action elements and whether to shoot those in spherical or anamorphic. Sort of just depends on what is more important for that shot, how hard will it be to add extra elements to the shot, etc. For example, a wide shot of a landscape shot in anamorphic in daytime in which you are going to add a digital matte painting, doesn't really make a difference whether you shoot the background in anamorphic or not, so if the anamorphic version is going to have better resolution, then go ahead. But a wide shot of a room in low-light with a lot of anamorphic distortion in the plate, with a pan or track in the shot and perspective changes, well, many efx compositors will have an easier time with spherical footage if you have to layer in objects into the shot that would have to track, bend and distort with the original anamorphic plate.

John Brawley · November 3, 2009

Here's the situation. Compositing a green-screened miniature that's blown up 12-15x onto a landscape (say: the squirrel that ate Manhattan).

I'd like the bulk of the film (the landscape) to be shot on anamorphic. Does this make it impossible to pull off the composition?

Some advice suggested the miniature should be a shot on a very short 10mm or so lens in order to get enough DOF to keep the miniature in focus. Are there anamorphic lenses that short?

Can some miniature elements be shot with spherical lenses, or will this pop out like a sore thumb and blow the whole effect?

Depends on the scale but you generally always want to shoot your miniatures at the deepest F stop you can. Yes we're talking 16, 22 or 32.

You will also find there are no cheats with using wider lenses. All that happens is that you have to move the object closer...much closer to get the same relative image size on film. You'll find the DOF roughly the same once you match the relative image size as far as perspective anyways. Plus when you're shooting that wide you start introducing other lens distortions that won't be in the original.

Anamorphics also won't be that wide, they generally don't focus as close and they certainly won't be at their best in that situation.

In fact, just a reminder, that lenses often look as bad if not worse than wide open when stopped all the way down.

I'd be inclined to shoot spherical and not worry to much about the anamorphic match. Spherical and at the deepest stop the lens will shoot.

jb

*EDIT.

On a recent anamorphic shoot, the VFX supervisor had me shoot geometry grids (a bit like a DX test chart) of all my lenses so that he could *map* the lens distortions onto his CG images. Im sure an experienced VFX super could guide you here to match the distrotions.