Shutter Angle (Shutter Speed) and Frame Rate Comparison Tests – Canon 5D Mark II

So I’ve got an intern for the summer… Very interesting chap named Brandon as well…   Introducing… Mr. Brandon Levi Brown.

Brandon’s a local graphic design student, but also wanting to branch out and learn more about photography, videography, and web work as well.  It further helped that we knew each other from a previous chapter of our lives…

As we began discussing the topic of video, several questions started arising.  I was explaining my overall workflow with the Canon 5D Mark II for video, and Brandon asked, why I opted to use the settings I did.  I saw this not only as a huge opportunity to share some knowledge with him, but also to share it on the blog.  Further… what better way to show these concepts than actually creating some Comparison tests to help try and visualize the differences and ultimately my reasoning for my choices.

I mentioned to him that my general / standard settings are always as follows:

• ISO: always a multiple of 160, and very rarely exceeding ISO 1600
• Frame Rate: 24fps
• Shutter Speed: 1/50s (thereby creating a ~180 degree shutter angle, more on this shortly)

Using ISO in Multiples of 160

My reasoning behind this is actually a result of two things… the Shootout videos produced by Zacuto stating that ISO multiples of 160 are actually native ISOs whereas the others are digital modifications.  Thereby ISO 200 will actually appear more noisy in video than ISO 320.  Secondly… I had first noticed this concept being used by Shane Hurlbut on the shoot for “The Last Three Minutes“.  The PA Manager then informed me of the same bit of information that Zacuto later produced.  I have not done a comparison test on this particular issue, but I highly recommend watching the Zacuto Shootout…  Not just for this, but for anyone shooting on this format.  Really really great empirical tests, and lots of great information.

24 Frames per Second (24p or 24fps)

Why 24 Frames per Second?  24p (24 Progressive) or 24 Frames Per Second is popularly considered to be the standard for the “cine” look.  The other primary option would be to shoot at 30 Frames per Second, which gives more of a video / tv newscast look.  These settings are all of course only based upon the NTSC standard (USA) and not PAL (EU).  There are a number of interesting articles about the history / background of 24 and 30p, explaining the correlation to electrical frequency, and the development from 18fps to 24fps as a a standard in film.  I’m not going to dive as much into that…  Still today, the majority of films are produced at 24 Frames Per Second, and therefore, as I want to achieve a filmic look, I also opt to use 24fps.  So curious what the difference looks like?  Brandon and I shot a number of sequences primarily for the Shutter Angle / Shutter Speed Comparison tests, but also did multiple tests at both 24 and 30 fps to hopefully show the difference.  Unfortunately there isn’t a way, that I’m aware of, to combine both 24 and 30 fps into one timeline without altering the frame rate, so I’ve uploaded two separate clips here to show the difference, hopefully for now, this will suffice.  The Canon 5D Mark II (for NTSC) currently can shoot at 1920×1080 at 24p, and 30p, and at 640×480 at 30p with the latest firmware upgrades (which I HIGHLY recommend).

Frame Rate Samples (Part 1 of 2) – 24p from Brandon Cummins on Vimeo.

Frame Rate Samples (Part 2 of 2) – 30p from Brandon Cummins on Vimeo.

Shutter Angle = fps x 360degrees / Shutter Speed

So what the heck is Shutter Angle?  A term and technique often used by cinematographers to help achieve a very distinct look.  Essentially, it refers to the amount that the “film” or sensor, is exposed to light, and how much it is exposed to dark.  It is originally based upon a rotary shutter, which would have an opening cut into it to allow for just this concept.  So a 360 degree wheel, cut in half = 180 degree shutter.  A 180 degree shutter angle is also considered to be a filmic / cine standard.  That said… at 24fps, 1/50s shutter speed is the closest option to a 180degree shutter angle (1/48s would be 180degrees, but that is not an option for shutter speed).  As you increase the shutter speed, you in turn decrease the shutter angle.  This creates more sharpness and clarity per frame, but can also create an aggressive / intense effect.  This technique would best be used for chase / action sequences, or as an attempt to create an edgy / gritty feeling.  The film “Saving Private Ryan” was shot using a small shutter angle (I believe 11degrees), to help intensify the action sequences, and to recreate old WWII newsreel style footage.  These tests are not empirical by any means… but will hopefully at least showcase the concept of shutter angle.  Obviously other in-camera settings must also be altered to achieve proper exposure when tweaking the shutter speed…  Therefore some of the tests (inanimate objects) adjust both shutter speed and aperture… this also alters the depth of field, which further affects the overall “look”.  The other tests, starring Brandon Levi Brown, adjust shutter speed and ISO.  Thereby not altering the depth of field, and allowing (at least in my opinion) the effect of shutter angle to be better discerned.  Settings for individual shots are listed in the video.

Shutter Angle Tests – Canon 5D Mark II from Brandon Cummins on Vimeo.

This entry was posted on Wednesday, July 7th, 2010 at 2:12 pm and is filed under Blog, Media Related and tagged with 24p, 30p, Aperture, canon 5d mark ii, Comparison, Frame Rate, ISO, Shutter Angle, Shutter Speed, Tests. You can follow any responses to this entry through the RSS 2.0 feed.