{"id":120143,"date":"2019-09-16T07:00:24","date_gmt":"2019-09-16T12:00:24","guid":{"rendered":"https:\/\/www.premiumbeat.com\/blog\/?p=120143"},"modified":"2019-09-09T11:43:51","modified_gmt":"2019-09-09T16:43:51","slug":"how-to-create-split-diopter-effect","status":"publish","type":"post","link":"https:\/\/www.premiumbeat.com\/blog\/how-to-create-split-diopter-effect\/","title":{"rendered":"Post-Production Tips: How to Create a Split-Field Diopter Effect"},"content":{"rendered":"

Using a split-field diopter used to be much more common, but it’s still an effective tool. What is it, and how can you create the effect yourself?<\/h2>\n

After having fallen out of favor over the last few decades, the split field diopter<\/a> is coming back into cinematography style \u2014 and you don\u2019t necessarily need one to get two different planes in focus in the same shot.<\/p>\n

A split-field diopter is a half-oval piece of glass that sits in front of a lens, creating two separate depths that are both in focus at the same time. It is a slightly odd effect because the background of the two zones can still be blurry if the camera is set to a low f-stop.<\/p>\n

\"Post-Production<\/a>

Split-field dipter (via Hoya<\/a>).<\/p><\/div>\n

Composing within the frame has become a bit of a unicorn in Hollywood because the average shot length dropped from 6 seconds to 2.5 seconds over the last 40 years. Most directors opt to cut between shots rather than keep both in frame at the same time \u2014 because you have more control in post over how long each shot is on the screen. A split-field diopter shot is a more elegant (but in some ways more limiting) method of showing the audience two subjects at the same time \u2014 and letting them chose which to look at.<\/p>\n

The Hitchcock Rule<\/h3>\n

Hitchcock stated that the size of an object in the frame should be in proportion to that object’s significance to the plot. The classic example of this is a big gun in the foreground. It\u2019s hard achieve these kind of shots without a split-field diopter because you would need to shoot at f16 or above on a super 35 camera to get sufficient depth of field, and that takes a ton of light. The same goes for any deep-focus shot, like in 12 Angry Men<\/a><\/em>. (There’s a reason the actors were sweating.)<\/p>\n

\"Post-Production<\/a>

Image via 12 Angry Men<\/em> (Orion-Nova Productions).<\/p><\/div>\n

Peter Jackson, a fan of Hitchcock, used this rule multiples times in The Lord of the Rings<\/em> trilogy. The One Ring had massive significance for the plot, but it was a tiny object, so Jackson used numerous split-field diopter shots to make it loom large in the foreground. He also used a giant prop ring to get a similar effect without having to deal with the blurry line a split-field diopter creates.<\/p>\n

\"Post-Production<\/a>

Image via The Fellowship of the Ring<\/em><\/a> (New Line Cinema).<\/p><\/div>\n

The ring dominates that frame, but we still see the characters in the background \u2014 and the ring’s relation to them.<\/p>\n

The downside of split-field diopters is you need to have one that suits the lens you\u2019re using, customized to the two distances you’re hoping to get in focus, which takes preplanning and some specialized equipment.<\/p>\n

An alternate way of getting deep focus in a shot is to combine two shots in post. You shoot your shot twice \u2014 once with the front plane in focus and a second time with the back plane in focus. You then combine those shots in post by masking the top one, and the result is a shot where both objects are sharp.<\/p>\n