Onyx Boox Nova Air C review: The trade-offs of Kaleido Plus outweigh its benefits
Onyx BOOX Nova Air C feels like a prototype device
Nova Air C is Onyx BOOX’s third attempt at a colour e-reader. Before, we had the six-inches Poke 2 Colour with an older Kaleido colour screen and Nova 3 Colour that has a Kaleido Plus screen. There are subtle differences between the 7.8-inches Nova 3 Colour and Nova Air C:
Nova Air C is the first colour e-reader supporting E Ink’s On-Cell Touch technology, which E Ink claims deliver a better contrast ratio and colour saturation.
The processor is upgraded to a Snapdragon 662 octa-core processor (BOOX Nova 3 Colour is configured with a 636 octa-core processor).
While Nova 3 Colour has a single white front light, Nova Air C is configured with white and warm lighting.
The battery capacity has been downgraded: Onyx BOOX Nova 3 Colour’s battery capacity is 3150 mAh, and Nova C is 2000 mAh.
Onyx BOOX Nova C weighs 30 grams less.
The upgrades noted above do lead to improvements. However, I believe – as is customary with Onyx BOOX – the updated model is unjustifiable and offers too minor improvements to warrant its release. It would be better if Onyx BOOX had a slower hardware update cycle and concentrated on improving the software experience. As will be seen below, the same drawbacks that hindered Onyx BOOX Nova 3 Colour remain with the updated Nova Air C.
Appearance and screen
The black and white Nova Air looks very similar to Nova Air C. Both e-readers removed the bottom button, have the same dimensions (weighing 235 grams) and come with an updated stylus that magnetically attaches to the right side. The only difference is that Nova Air’s shell is white, while Nova Air C is black.
Nova Air C’s screen uses E Ink Kaleido Plus technology – the same technology used in the previously released Nova 3 Colour. The key difference between both models is Air C’s use of E Ink’s On-Cell Touch with ePaper modules. According to E Ink, On-Cell Touch integrates the touch layer into the display modules (see image above). Due to this integration, E Ink states that contrast ratio and colour saturation improves:
E Ink now offers On-Cell Touch with ePaper modules to provide improved optical performance. This Touch solution provides an increase in the contrast ratio of black and white content of 30%, providing readers with clearer text content. When used in E Ink Kaleido Plus, the color contrast ratio is increased by 40% and the color saturation is increased by 15%, providing an enhanced display for color eBook and eTextbook content.
I haven’t used Nova 3 Colour before to judge if there is a significant difference in contrast and colour saturation with the On-Cell Touch upgrade. However, compared to monochrome e-readers, Nova Air C’s contrast is worse. Due to the Colour Filter Array (CFA), the screen appears dark grey with a green tint (see image below comparing Nova Air C to Kindle Paperwhite). Further, horizontal lines are visible in bright conditions or when the front light’s brightness is increased. The textured effect produced by the lines is due to the CFA on top of the black and white film.
Due to the dark screen, except for very bright conditions, the front light needs to be turned on for comfortable reading. As a result, Nova Air C is not suitable for users who use E Ink to avoid light emissions when reading. Another downside with the front light being often needed is the impact on battery life. The Nova Air C’s battery capacity is already relatively small, and the front light continuously turned on further diminishes its endurance.
Black text is rendered in 300 PPI and colour in 100 PPI. Again, while 300 PPI is the same as most e-readers, the blacks appear faded in comparison. The colour adds value to the reading experience – e.g., reading graphic novels and analysing diagrams – but they expectedly lack the saturation and vibrancy of tablet screens. The lack of vibrancy and faded appearance might be acceptable if there wasn’t an impact on the screen’s appearance and the contrast of black text.
There are three ways to change the way colours appear in a designated E Ink centre that is accessed via the top drop-down menu: contrast enhancement, colour saturation, and colour brightness. Applying any changes in the E Ink centre applies to both colour and black content.
Onyx BOOX has remedied the ghosting problem that affected previous colour models. Within BOOX’s Neo-Reader, using regal mode removes most of the ghosting. Also, navigating the home screen and menus generates little ghosting as the software frequently forces a full refresh between touches.
Stylus and note-taking
Onyx BOOX has pre-applied a screen protector, but it doesn’t produce a paper-like texture. The updated stylus – also used with Nova Air, Note 5 and Note Air 2 – has a nib that generates more resistance and a pencil-like feel when writing. The only downside with the stylus is the removal of the eraser end.
The notebook application is mostly the same in BOOX’s black and white models, with the difference being the added colour support when using the writing tools. One useful feature is the use of the highlighter pen in yellow.
Performance and battery life
Onyx BOOX uses the best performing processors in the e-reader space. Thus, it is not surprising to see Nova Air C’s processer upgraded to Snapdragon 662. Compared to Nova 3 Colour, the upgraded processor boosts performance, but the difference is not significant. Navigating files, opening large PDF documents and browsing the web are handled smoothly.
One downgrade is the decrease in battery capacity – Nova 3 Colour has a 3150 mAh battery capacity, while Nova Air C has a smaller 2000 mAh battery. Like the downgraded BOOX Nova Air, battery life is significantly decreased. Battery life lasts for 2-3 days in regular usage, with the front light set below 15%. When note-taking – with Wi-Fi turned off and the front light set below 10% - the battery drains about 5% every thirty minutes of continuous writing.
The same feature-rich software
There is nothing new to add regarding software. Onyx BOOX’s software is incomparable for its wide array of features and robust PDF support. The confusing organisation of these many features requires a steep learning curve for new users. After an initial period of getting used to the idiosyncratic placing of features, the amount of control available makes it worth the effort.
A strange omission is the lack of support for colour in Neo-Reader. For example, after selecting text for highlighting, there is no possibility to choose a colour (see image below).
A note on the official smart cover
Nova Air C has pogo pins in the middle of its left side that can attach to an official smart cover with page-turning buttons (the cover comes in two different colours). The weight of the cover is 149 grams (the cover and Nova Air C weigh 419 grams). As with other Onyx BOOX accessories, the cover could be developed better. While its aesthetic is a question of personal preference, there are design issues that need mentioning:
There are no magnets built into the cover to hold it firmly when folded; as a result, it slides and gets in the way when reading.
The page-turning buttons work well, but there is no way to reset their forward and backward direction in user settings. What is supported is setting the functionality of the buttons when long pressed – it is possible to set a long press to take a screenshot, rotate the screen and instigate a full refresh.
I noticed a bug with the smart cover when used within the notebook application – the stylus does not activate the ‘more’ icon when selected, and the search icon needs to be pressed multiple times to work (the problem appears when the toolbar is set to the left).
Concluding remarks
The simple matter is Kaleido Plus has inherent limitations that detrimentally impact the reading experience. The consequence of implementing the CFA on top of the black and white film is seen in the dark screen and poor black contrast. The introduction of On-Cell Touch technology does not remedy the problems produced by the CFA. Consequently, as colour E Ink is still in a developmental stage, Nova Air C feels like a prototype device.
The question is if adding a CFA to BOOX Nova Air C is worth the drawbacks noted above. The answer must be negative – the colours are muted, and use cases are limited. The black and white Nova Air costs less and does everything Nova Air C does, minus the colour. As one among many mid-sized e-readers whose screens are clearer and better at rendering black and white content, it is difficult to recommend Nova Air C.