Image Image Image Image Image
Scroll to Top

To Top


Splitting The Focus in De Palma’s ‘Blow Out’

On 11, Oct 2013 | 7 Comments | In Cinematography, Low Budget Filmmaking, Production | By vashi

Schneider Optics Split Focus Diopter

Schneider Optics Split Focus Diopter



A Split Focus Diopter is half convex glass that attaches in front of the camera‚Äôs main lens to make half the lens nearsighted. The lens can focus on a plane in the background and the diopter on a foreground element. In the 1970’s and 1980’s, Brian De Palma championed the use of this tool to enhance the visual and emotional experience of his films.

The Split Diopter allows for Deep Focus cinematography but requires much less light. It also delivers a distinctive look that blends sharp and out-of-focus imagery all in one frame. Subjects in both foreground and background can be kept in focus. In the video below are all 15 Split Diopter shots from Brian De Palma’s film Blow Out (1981).

15 Diopter shots in De Palma's Blow Out

De Palma used the Split Diopter to enhance the drama in ‘Blow Out’



You have probably seen many Split Diopter shots and not even realized it. They carry an other-worldly look that feels different from a normally lensed shot. It can be perceived as disorientating as our vision doesn’t work the same way.

Robert Redford in All The President's Men

All The President’s Men (1976)


The Split Diopter has a clear line down the middle of the frame between foreground and background.

The Split Diopter shot in Reservoir Dogs

Obvious Split Diopter shot in Reservoir Dogs (1992)


Vertical lines in the frame can be used to hide the shift between foreground and background focus.

The Slave (1962) split diopter shot

Vertical lines hide the Split Diopter in The Slave (1962)


Darkness in the frame can also be used to disguise the use of the Split Diopter.

Split Diopter shot from The Untouchables

Darkness hides the Split Diopter in The Untouchables (1987)


Split Diopters shots can add enhanced hyper-realism to emotional moments.

Smallville's Lex Luther and the Split Diopter

Smallville (2011) BTS photo by director Greg Beeman


Robert Wise used the Split Diopter extensively in Star Trek: The Motion Picture.

Star Trek The Motion Picture uses the Split Diopter

Star Trek: The Motion Picture (1979)


Steven Spielberg splits the screen in Jaws.

Spielberg uses the split diopter on this beach shot in Jaws

Split diopter shot from Jaws (1975)





Halt and Catch Fire S03 E07

Halt and Catch Fire S03 E07


Margot Robbie in the season 42 premiere of SNL

Margot Robbie in the season 42 premiere of SNL


The bottom line is that Split Diopters help achieve the cinematic and story goal of emphasizing subjects as needed by the Director and DP. When utilized for decisive or important moments…they can visually amplify the dramatic tension for the viewer. If used too often, just like with any other technique, the magic of this tool will diminish and the effect will become obvious.





Million Dollar Baby (2004)



Close Encounters of the Third Kind (1978)



Used sparingly and hidden within the frame…Brian De Palma chose 15 moments in ‘Blow Out’ to bust out the Split Diopter.



Until next time…




4 Lens under $100 for Amazing Lens Flares

Another great article about Split Focus Diopters by Jan Stripek.

Schneider Optics 138mm Split Diopter

Tags | , , , , ,


  1. Great post Vashi!

    I remember the first split diopter shot I remember seeing. It was in Tarantino’s “Death Proof” and I remember thinking “what the hell is that line down the middle of the screen?”.

    About the second shot of the owl though…(the one that starts at 1:16) it almost looks to me like that could be an optical composite. The way the background shows through his head as it is turning looks like a composite to me. I could be wrong about that though.

    A quick question. Can a tilt shift lens be used to achieve the same effect?

    • You can understand about 1:16 by the shaking of the camera… It shows it all.

    • vashi

      I think you’re right Evan. The wobble of the owl suggests optical for that. Looks like De Palma did a “fake” split diopter shot. Good eyes!

Submit a Comment