Fujifilm’s new sensor - How the innovation works
Bayer array
Bayer
array
A conventional-colour filter array has a
repeating arrangement of 2x2 pixel sets that generate moiré and false colours
when shooting lines and other regular- repeating patterns. This can cause some
serious issues and unwanted image artefacts for everyone, ranging from
architectural to textile photographers.
Lens with optical low pass filters
Lens
with optical low pass filters
Traditional optical low-pass filters
inhibit moiré and false colours but consequently lead to a loss in resolution.
This is still the preferred option for the vast majority of photographers, but
is unacceptable for many others, particularly those familiar with medium-format
cameras.
Fujifilm’s new array
Fujifilm’s
new array
The high aperiodicity (randomness) of the
arrangement of pixels in 6x6 sets reduces the occurrence of moiré. Also, the
presence of an R, G and B pixel in every vertical and horizontal pixel series
minimises the generation of false colours and delivers higher
colour-reproduction fidelity.
The X-PRO 1’s filterless system
By removing an optical low-pass filter,
moiré and false colours are eliminated, but high resolution is maintained.
Inspired by the natural random arrangement of the fine grains of silver halide
in film, the new filter removes a major shortcoming of digital photography that
prevented some commercial photographers using a DSLR.
A camera without filters
The inner workings of Fujifilm’s
revolutionary new model
A
camera without filters
Fujifilm’s X-PRO 1
The Fujifilm X-Pro 1 is a system camera and
the first of its kind to lack an Optical Low-Pass Filter (OLPF).
Colour and shape
As light passes through the lens, the camera
interprets the scene using a set of complex algorithms.
Pressing the shutter
As the image is taken, shapes and colours
are interpreted by the colour filter and image processor.
Filtered out
At this point, a filter would normally
reduce the effects of moiré and false colour at the sacrifice of sharpness.
New sensor
In this case, the X-Pro l’s new sensor,
with a completely different RGB pattern to regular sensors, solves the problem.
Picture perfect
By the time the finished image hits the
LCD, it has already been processed and corrected.
Nikon’s tips for cameras without an OLPF
Nikon’s
D800E allows light to pass straight to the sensor with no filtering.
There are a few things that you can do to
minimise the false colour and moiré that is inherent in a camera that does not
incorporate an optical low-pass filter. The best way to solve the problem
istofixthe shooting situation before the image is captured.
- Since the angle of the camera and subject
causes moiré, slightly changing the angle of the shot (by rotating the
camera) can remove or change any moiré that is present.
- Changing the angle relationship by moving
left or right, up or down can reduce moiré.
- Moiré is caused by very sharp focus and
high detail on fine patterns; this means that slightly changing the focus
point changes the sharpness and can help to remove moiré.
- Different lenses or focal length settings
can be used to alter or remove mol ré.
- Stop the lens down about 3 f-stops from
its maximum aperture. This requires you to shoot around f5.6 or f8 all the
time. Stopping the lens down to a smaller aperture (such as f11 or f16)
will cause diffraction to lower sharpness, reducing the benefit of the
OLPF. This will easily negate the benefits of the D800E.
- You can remove the false colour in post-production
on the computer easier than you can the moiré pattern itself. Nikon
Capture NX2’s moiré reduction tool for NEF (RAW) files may be able to
remove some or all of the colour moiré that appears in the final image.
As good as large format?
Could
this little powerhouse really rival a large-format film camera?
Akira Kumagai thinks so. Born in Japan and
studying at Sweden's Royal Institute of Art, Akira specialises in product
photography and magazine work, and lectures at seminars both in Japan and
abroad. “I still use a large-format film camera not only because of its
capability for being enlarged for use in outdoor billboards, posters and
full-page newspaper advertisements, but also because it offers finer colour
gradations, superior to digital cameras," he explains. "When you
shoot a blue sky, a large-format camera can capture natural and subtle
gradation of colours, rather than single-colour reproduction typically done by
digital cameras. I can somewhat relate to landscape photographers who still
shoot with 4x5 cameras carrying positive film."
His experience with the Fujifilm X-Pro 1’s
new sensor and the sharpness achieved without an OLPF has stunned him. "It
has been about six years since I started shooting digital. The X-Pro 1 offers
descriptive performance comparable to film cameras. This experience really made
me think that I might even be able to give up a large-format camera for work as
long as i had the X-Pro 1.”
