The LUMIX G9II was designed with the wants of portrait, panorama, wildlife and sports activities photographers high of thoughts. Sadly, these broad photograph use instances place distinctive challenges on the imaging sensor of the digicam.
Through the design section of the G9II, LUMIX engineers recognized 4 core efficiency standards for the brand new sensor: larger decision than the earlier mannequin, improved excessive ISO picture high quality, double the body charge of the earlier technology sensor, and elevated dynamic vary.
Many of those targets can counteract one different. For instance, extra decision normally sacrifices excessive ISO efficiency, and quicker readout speeds can scale back dynamic vary. Thus, a number of new approaches have been required to achieve the design targets.
Mild and photons, photosites and diodes: A primer
To be able to perceive the extent of engineering devoted to the design of the G9II sensor, a primary understanding of how a digital digicam captures the sunshine that turns into a picture is required.
As gentle (measured in photons) displays off a floor being photographed, the photons enter the digicam lens and are captured on the picture sensor’s photosites or pixels (we are going to name these diodes, since that is their technical time period). The diodes then convert the photons into electrons, that are later digitized and symbolize the ultimate picture.
A diode has three axis: X (peak) and Y (width) decide sensor sensitivity, whereas Z (depth) determines the utmost saturation level of the diode. On this article part, we are going to focus on the X and Y axis.
The X and Y axis are nearly all the time the identical size, since most diodes are sq.. The bigger these dimensions, the simpler it’s to seize photons when there are usually not many out there (when it’s darkish, for instance). Because of this, a bigger diode is fascinating – however the bigger the diode, the decrease the decision.
Because of this engineers are continually in search of methods to extend the X and Y axis by eradicating materials from in-between the diodes. To simplify this idea, the larger the diode, the higher the image when it’s darkish – however decision is misplaced within the course of.
(Picture credit score: LUMIX)
Greater decision with improved excessive ISO high quality
Whereas the unique LUMIX G9 had a 20.1MP CMOS sensor, the G9II has a 25.21MP CMOS – a 22% improve in decision.
As famous, if the decision is elevated the diode will get smaller – which suggests much less seize space when photons are usually not plentiful.
How did the sensor design group handle this problem? They merely eliminated the wiring and extra materials that have been obstructing the diodes on high of the sensor, and embedded them behind the diodes within the silicon of the CMOS sensor. This positive factors again a lot of the diode space misplaced to the additional decision, an answer generally referred to as a backside-illuminated sensor (or BSI for brief).
(Picture credit score: LUMIX)
Quick readout sensors with no loss in dynamic vary
The place the G9 was able to capturing 4K video at 60fps, the brand new G9II is able to capturing C4K video at 120fps – double the body charge.
An inherent benefit to the Micro 4 Thirds sensor is its measurement; a smaller sensor can naturally learn out its info quicker. The design group checked out processes that added latency in changing the photons into knowledge, and decreased these phases or eradicated them completely.
With regards to stills, the G9II delivers a best-in-class mixture of steady burst capturing (60fps) with steady autofocus and glorious dynamic vary.
Tying all of it collectively: Dynamic Vary Increase
So, the G9II sensor can learn out C4K video at 120fps however the photograph operate can solely ship 60fps with steady autofocus. What provides?
The sensor has a operate referred to as Dynamic Vary Increase (DR enhance, for brief). If the digicam body charge is decreased to 60fps as an alternative of 120fps, this gives extra time for pixel output synthesis – deploying two completely different sign amplifiers, one optimized for clear shadows and one optimized for max dynamic vary.
These two attributes are mixed (synthesized) into one body that has clear shadows, no magenta shift and nice highlights that do not clip too early.
This mixture delivers class-leading decision, ISO sensitivity, readout velocity in steady AF and, most necessary of all, glorious dynamic vary that permits for extra latitude to regulate photographs in submit, to get the perfect element out of the shadows whereas sustaining wealthy and vibrant colours.
You may be taught extra in regards to the G9II and its options right here.
