Choosing Digital Cameras
Producers should use the best, highest quality capture systems
for their specific needs. With the current range of cameras used for GS there
is no need to go below 6K (6144×3160) resolution – see below.
A current exception is high-speed shooting, where the highest
resolution currently available for speeds greater than 120fps at 4K is the
Vision Research Flex 4K.
When this document was published, the digital cinema cameras most
commonly used for GS projects included: IMAX/Arri Digital Camera, Arri 65, Sony
Venice, RED Weapon Helium and RED Weapon Monstro. The Panavision DXL and Canon
C700 Full Frame can also be considered
Record in the camera’s raw option whenever possible. This will
ensure the highest quality acquisition format. Record the raw file
uncompressed, if the camera system allows it (e.g., Arri 65, or Sony Venice
recoding to a Sony AXS-R7 recorder.
Before making any firm decisions on image capture,
filmmakers are strongly advised to confer with an experienced GS director of
photography, post-production supervisor, GS editor, and/or a camera rental
company that is used to serving the GS industry.
In 2014 the GSCA Technical Committee ordered digital camera and
film camera tests, known as Bring Back Our Wide Shots (BBOWS), so that GSCA
members could evaluate the differences between various digital cameras and
compare them to film from original neg.
In the first BBOWS test (BBOWS 1), the digital cameras were
compared to scanned 15/65mm negative. The test used RED Epic, Red Dragon, Arri
Alexa, Sony F65, and Canon c500. None of the material in this test was
digitally re-mastered. BBOWS 2 (shown at GSCA’s Film Expo in March 2015) took
the material from BBOWS 1, left out the Arri Alexa and Red Epic, and digitally
re-mastered the digital material. The film material was not digitally re-mastered,
which led some audience members at the GSCA to ask why it did not look as good
as expected. BBOWS 3 (a proposed future test using some of the same and some
new cameras) will rectify this by digitally re-mastering all the material (film
and digital). As an interim solution, BBOWS 2.1 will take the scanned film
material, digitally re-master it, and reinsert it back into the test. DCPs of
BBOWS 2 are available to members from Fotokem for a small fee to cover costs.
In 2017 the GSCA Technical Committee created a camera test that
illustrated techniques for using widescreen digital cameras to create 4:3
aspect ratio content for giant flat screen and dome theaters. This demo called
Save our Aspect Ratio (SOAR) featured a number of setups shot for standard
widescreen framing, then framed with extra headroom. These shots were cropped
for 4:3 (scaled up to match height of the 4:3 frame while losing horizonal
resolution), stretched to 4:3 (by stretching the pixels in the upper third of
the frame to fill the aspect ratio), and also composited with shot extensions
(footage shot on location with the camera tilted up above the scene, so that
these extra visual elements could be added to the original full-width shot,
preserving their original horizontal resolution). DCPs of SOAR are available to
all members from FotoKem for a small fee to cover costs.
In 2018 the GSCA Technical Committee produced a new camera test
called the 8K Digital Camera Comparison (8KDCC) in which five of the top 8K
digital camera went head-to-head in a performance test in varying shooting
conditions. The TC compared the following cameras:
- ARRI Alexa 65
- Canon C700 Full Frame
- Panavision DXL2
- RED Weapon Monstro
- Sony Venice
James Neihouse used matching Leica Thalia lenses on each camera,
ND filters as needed to allow the same exposure setting, and matched focus. He
shot as many cameras simultaneously as possible, sometimes all five, but
usually three-and-two or two-and-two. One of the cameras was unavailable for
the first day and a half of shooting, so the “C” camera does not appear in all
setups.
FotoKem, supervised by Rick Gordon, did base color grading on
each shot to match exposure and skin tones as needed.
The demo presented each setup as a 15-second shot from each of
the five cameras (labeled on screen as a single letter: A-E), so that the
audience would not know which camera was which. The demo has two sections:
- The first section cropped all cameras to 4:3
using the entire vertical height of each image. - The second section used the entire width of each
sensor, revealing the cameras’ native aspect ratio, with black filling the top
of each frame to complete the 4:3 container.
After watching the cropped clips, the team revealed which camera
was which, and viewers could once again evaluate the full width version of the
shots.
The TC mastered a 4K DCP in IMAX laser format and also output a
6K frame sequence for digital dome theaters.
A DCP of the demo is available free to all members in IMAX laser
format for a small fee to cover costs.
Lens Choice
- Lens choices are critical to ensure maximum
resolution. - Cinema lenses are essential. Using HDTV lenses
on digital cinema cameras will negatively impact picture quality. Even high-end
35mm still lenses have significant drawbacks in terms of focus, aberration, and
build. - The lenses’ resolution must match or exceed that
of the sensor. - Arri/Zeiss Ultra Primes are a good choice if
prime lenses are preferred. - When shooting 3D, matched lens pairs are
essential, whether primes or zooms. - Angenieux Optimo DP zoom lenses come in
factory-matched pairs in 16–42 and 30–80mm focal lengths and are the industry standard
for 3D zoom lenses. However, these lenses will not cover the full chip of the
new full-frame cameras.
Non-Camera Capture
Non-camera capture includes, but is not limited to, CGI or photographic
animation; stock, library, or found footage; and still photographs. For CGI
animation, 4K is the minimum quality and GS films are now being mastered in 6K.
For stock, library, or found footage, use the maximum scanning resolution
of the source material, with a minimum of 4K. Footage scanned at lower
resolutions, e.g. 2K, may have to be presented at less than full screen. Most
material will require noise removal, sharpening, and removal of source
artifacts.
Photographs that will be scaled or zoomed should be scanned at
high enough resolution to maintain sharpness at 4K. For instance, a photograph
to be zoomed in 50% will require at least 8K resolution.
Consider oversampling any non-camera material. For example,
create CGI at 8K and output at 4K. Testing often shows that scanning at 8K or
12K and outputting at 4K is visually superior to scanning at 4K and outputting
at 4K. IMAX digital projection systems are 4K, so shooting on an 8K camera
(even cropping in post to 4:3) is oversampling. However, projection systems
from other vendors, such as D3D Cinema and Evans & Sutherland, currently
have resolutions of 6K and 8K.
The two native resolutions of the FotoKem film recorder are
5464×4096 and 4096×3072. The lower resolution version is the one most commonly
used as that is the projection resolution of the IMAX laser projectors,
including the new digital dome projections system from IMAX. FotoKem is capable
of scanning 15/65 at full 8Kx6K however. As a side note, if you zoom in on one
of those frames in Photoshop, you will see that an 8K scan FAR out-resolves the
actual film. There is not 8K worth of resolution in an 15/65 frame.
Time-lapse capture is currently being achieved by shooting raw
images with high-quality digital single-lens-reflex still cameras (DSLRs), such
as Nikon D800/810 or Canon 5D MkIII. Motion controlled time lapse rigs give
filmmakers a unique storytelling tool.
Some films (e.g., Jerusalem) have used High Dynamic Range
(HDR) time-lapse, where bracketed frames are combined into a single image, to
great effect.
The management of these large, high-resolution images in post is key
to a high-quality final result. Discuss this with your DoP and/or post house before
shooting.
Dome-Specific Capture
Ideally, capture for dome theaters will use a fisheye lens to
create distortion in the image which projects undistorted on the hemispherical
screen. As the IMAX dome theaters have a screen which is much closer to the
audience than flat-screen IMAX, sharpness is most important on a dome. Action
should be placed low in the frame, and the top of the frame needs to be
somewhat darker than the bottom to minimize washout in the main action area via
cross-reflection. Cloudy skies should be avoided, and sky grads are common for
the dome to darken skies even more.
3D Dome-Hybrid Capture
If 3D will be the primary format, but a dome version is also
planned, it is vital to keep the point of interest close to the dome visual
center, as illustrated in the figures above. Also consider capturing shots
twice, once with a preferred lens for giant screen 3D, and again with a
fisheye/30mm for the dome.
Greg McGillivray is an experienced GS director and
cinematographer. Below are points from a talk he gave at the GSCA’s fall 2013
conference, entitled “Aiming for the Sweet Spot.”
- Composition: Use shots which work well on the
dome. - Use wider lenses.
- Use forward-moving dolly shots.
- Keep
the horizon line low in frame. - Use
camera platforms – especially aerial – which are super steady. - Shoot
in high-contrast light conditions, under blue skies and avoid gray, pasty
skies. Use graduated filters to darken the skies. - Editorial
decisions are made keeping the dome experience in mind. Scenes that will excel
on the dome are selected - Prints destined for dome theaters are printed on
Kodak Vision Premier color print film/2393TM to give higher contrast, and
richer, more saturated color. - Prints destined for dome theaters have their own
slightly different color timing specifically to maximize the dome experience. - On To the
Arctic, for the first time, we edited and cut negative on a version which
was destined for the dome, at a cost of over $200,000.
Forward to 6. Digital Imaging Technician & Digital Lab Services
