Shooting anamorphic for 1.85:1 extraction to aide production design (3 replies and 3 comments)
I'm currently prepping my second feature film and it's a rather ambitious one given the budget. Everything needs to be dressed as 1996. In order to assist the production designer a bit, I'm considering proposing to shoot anamorphic for a 1.85:1 extraction for a shallower DOF throughout. The film is certainly not a scope film, but I thought this may be an interesting technique cropping it back to 1.85:1.
I know you're not typically keen to use anamorphics, but I was wondering if you're aware of any examples of this technique used on previous films?
I'm still trying to figure out the math from a technical standpoint for how much resolution I'd be losing on the crop.
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I think you’d get a more consistent degree of shallow focus using a set of T/1.4 spherical lenses wide-open than using anamorphic lenses that vary between T/2 to T/2.8.
Also, it’s not the anamorphic elements that get you less depth of field, it’s the fact that you need to use twice as long a focal length in 2X anamorphic to get the same view as a spherical lens cropped to 2.40. So if you crop an anamorphic lens to get 1.85, you probably aren’t using twice as long a lens to get the same view so you aren’t getting the equivalent of 2-stops less depth of field.
The focal length chosen to get the desired field of view affects the depth of field characteristics, which is why a 50mm 2X anamorphic gives you less depth of field than the equivalent 25mm spherical if both use the same width sensor area and are shot at the same f-stop and distance.
The 1.85 extraction from spherical Open Gate is 3424 x 1851 pixels / 28.25 x 15.27mm.
1.85 extraction from 2K ANA would be 1984 x 2145 pixels / 16.37 x 17.70mm.
This works out to only be a 1.15X difference in crop factor, meaning that your focal length in anamorphic would only be 1.15X longer than the spherical focal length in Open Gate if both were framed for 1.85 (so you'd use a 29mm lens in 2X anamorphic to get the same view as a 25mm in spherical if both end up in 1.85). That's not a big difference, only effectively 1.15-stops less depth of field in anamorphic if both were shot at the same f-stop. And considering that you can get T/1.4 primes like Master Primes or Leica Summilux-C's in spherical, you'd have to find T/1.4 anamorphic primes to get LESS depth of field by shooting in anamorphic -- if the 2X anamorphic lenses were T/2.1, then you'd almost have the same depth of field as a T/1.4 spherical. So practically speaking, there is no real advantage to shooting anamorphic for less depth of field if you were going to end up with a 1.85 frame.
Thank you David, for the clear mathematical breakdown. I suspected you’d have good insights into this idea.
In your opinion, do you think it would be foolish to use a 2.35:1 aspect ratio for a film where the two principal actors are a 6 year old and a 34 year old? We originally picked 1.85 for a taller frame to facilitate framing both actors in 2-shots considering the height difference. And there’s quite a bit of car interior work which concerned me with close-focus issues.
Anything is possible — “Logan” after all involves a child and some adults in a car and is shot in 2.40 anamorphic. But unless you specifically want that anamorphic look, then your first idea of 1.85 makes more sense, and you don’t need anamorphic to get a shallow focus — look at “Arrival” for example, shot at T/2 on Ultra Primes.
If you're interested in the look of anamorphic but want to maintain a 1.85 aspect ratio without having to crop, I recommend looking the 1.33x set of Hawk Anamorphics from Vantage:
However, AFAIK you'll need to get them shipped from Germany, as no rental house carries the 35mm set in the states, only Keslow has the 16mm set.