#1218. Pixii Monochrome

With this latest release, Pixii asks what makes a great monochrome camera. Here’s their answer.

As promised in my last article about the Pixii camera, I am keeping you updated with news from the Team at Pixii. Since I’m doing some work for Pixii, this post focuses mainly on information, explanations, and sample images. Where any opinion is ventured, it is purely based on repeatable observations made during my use of the latest camera.

 

Today, let’s talk monochrome.

There are a number of ways you can create a b&w photograph, each with its set of advantages and drawbacks, the most frequent being:

• A dedicated monocrhome camera such as those sold by Phase or Leica and sensor conversions such as those offered by MaxMax. These, in theory, offer the best quality, since they do away with the Bayer filter. The downsides are price and complexity (of owning a separate camera) and low versatility.
• Desaturating (or converting, via another method than desaturation) a colour photograph, in post-processing software. This is essentially free, if you already own both the camera and the software. The downsides are that software editors don’t always give you proper control over how colours are turned into b&w, and that there is some minor quality loss in the conversion. Also, purists will tell you you need to think mono to make good mono images. Colour cameras don’t offer a true monochrome workflow.
• In-camera profiles, with the added bonus that this often offers a variety of different styles. The downside here is the jpg format of the images, which can look gorgeous out of camera, but offer very little latitude for post processing, should you need to lift shadows, for example, because of their jpeg format.

 

 

The news

I hope it’s obvious by now that Pixii’s news(*) is monochrome related 😆

The company is offering a 4th way: in-camera RAW monochrome, from a traditional Bayer-sensor. In other words, and this is the big news:

All Pixii cameras from now on,
can be toggled between a RAW colour mode
and a RAW b&w mode.

The rest of this post answers the following questions: how is this done, how is it different from current options, what are the targeted benefits and what are the limits?

 

 

How does it work? How do you use it?

How it works, is an interesting question. All sensors are monochromatic by nature. By adding a Bayer filter on top, you can create the illusion of colour via an algorithm (called debayering).

Pixii founder David, previously a software engineer, has developed an algorithm that reconstructs the luminance map of the light falling on the sensor before passing through the Bayer filter, as if that filter and the debayering algorithm had never existed.

In other words, it simulates a camera with no Bayer filter. See more about this here.

How you use it is simple: a double-click on a rear-face button activates the monochrome mode. Another double-click puts the camera back in colour mode. The mode toggle is also accessible in the camera menu and in the app menu, if you prefer that option.

 

 

How is that different from previous solutions? How well does it work?

Compared to in-camera presets, this offers only one rendering (which as neutral as possible), not multiple emulations. The goal here is to preserve the most information in the RAW file to let the photographer edit with full latitude. And there obviously is a lot more of it, compared to jpeg files. Plus, if you want to use presets, you can just as easily shoot in colour and choose one of many presets in post. The Pixii being compatible with Adobe standards, there are numerous high quality presets to be used in compatible software.

Compared to converting to b&w in post, this solution offers the option of shooting in a pure monochrome workflow. Some readers will laugh out loud at this idea, others will cry tears of joy. You know who you are, please respect the other worldview. In terms of pure image quality, there’s not much in it. The “un-Bayering” algorithm is advanced (David has filed a patent for it), so it may offer a slight advantage but the company isn’t making any promises in that respect.

But its main goal is to provide untouched luminance, as if the Bayer had never been there. The advantage for purists, compared to b&w conversion, is that the file produced is extremely close to what a dedicated camera using the same sensor would provide. Tones aren’t decided by the post-processing software, but are a reflection of the light actually passing through the lens. The difference is more important than I ever imagined (see comparison example below). Also, this allows the use of colour filters, to shoot as experienced b&w photographers do.

   

Compared to dedicated monochrome cameras, the two obvious advantages are cost (and simplicity of carrying one camera vs two, swapping lenses …) and versatility, thanks to the very high quality host colour camera. It objectively is as close to two cameras in one (and for the price of one) as one can imagine.

Monochrome camera buyers know exactly what they want: untouched photons and the end to end monochrome workflow. The latter aspect is obviously fulfilled by the Mono mode, so the interesting question is how close to a Bayer-free camera using the same sensor this algorithmic reconstruction can come.

David explains that de-Bayering algorithms (that create the colour image from the sensor reading) are now so finely optimised that resolution-loss and dynamic-range loss are minimal. This is born out by comparative reviews, which tend to confirm that workflow is the main advantage of pure player monochrome cameras over Bayer-versions converted in PP. As for the cumulative degradation of the Bayer filter and Pixii’s monochrome algorithm, David estimates it at around 15%.

 

This is compared to a camera with the same sensor. And given the high-quality of the one in the Pixii and the following signal-processing circuit evidenced by the record-high score recently awarded by DxO, it’s unlikely the performance of the monochrome mode would raise concern for even critical shooters.

There is however a sensitivity penalty!

The red, green and blue filters in the Bayer matrix all block some light, to the tune of 1 or 1.5 stops globally. So, while the Pixii in Monochrome Mode loses no light compared to colour cameras, it does suffer a loss compared to pure b&w models. That being said, the sensor’s native ISO range in mono mode is roughly 100 – 8000 (plus 2 extra stops through “pushing”). You can decide whether that suits your needs or not.

 

 

So, what do those files look like?

Straight out of camera, a bit gray, due to the dynamic range and preserved highlights. I systematically underexpose all digital cameras by 1 stop, so the files also looked slightly dark.

But I processed some in a high-contrast way and others using a much softer approach for you to see the potential of those files in post. The important fact is they do not break up under PP torture.

Here are two shots, one made at f/1.4, the other at f/8 (the second is also a 2 horizontal frames vertical pano), both with the Voigtlander 35/1.4. See the cars in the bottom part of the second to get a feel of the very smooth tonal range of the camera.

 

Below, you have two photographs of the same scene, made a few seconds from one another. Both are vertical stitches of 2 horizontal frames, to produce a more or less square result. Aside from this, no PP was applied.

The first was shot in monochrome mode. The one below was shot in colour, and I then clicked the “Black & White” Treatment button in Lightroom. As you can tell, the two are different, with the pure mono being less contrasty and smoother. The tone curve of the monochrome mode is apprently modeled on b&w film.

 

 

How does it compare with …XXXX… ?

It’s likely I haven’t tested …XXXX… and it’s absolutely certain I haven’t compared …XXXX… directly to a Pixii 😉 So, how about some facts instead?

Here are choices made by the team that go in the Pixii’s favour when using M-mount lenses (besides the fact that many M-mount lenses are superb technically, and very small) :

• The sensor uses an optimised stack. It’s as thin as possible to play nice with the widest possible range of lenses, even from the film era (that obviously had zero filter stack). Most cameras today have very thick filter stacks that induce smear with those same lenses.
• The sensor uses BSI technology. I’m not sure many other strictly monochrome camera do. BSI sensors have the sensitive pixel at the surface of the sensor. Non BSI sensors have that sensitive surface at the bottom of a little well. As rays come at an angle in the corners, far less light reaches the bottom than the surface, inducing vignetting and colour shifts. The Pixii is largely immune to this.
• The sensor is APS-C. So its edges and corners do not use the outer regions of the lens’s image circle, that have the most flaws. You get the charm of old lenses, not the troubles 😉

 

 

Then, there’s the electronic shutter, that speeds up to 1/32 000s and allowed me to shoot wide open into direct sunlight.

Also, a fun side effect of the DNG file is that it is actually a color file containing only luminance information. This means you can actually play with the colour channels to create your own toning. Coupled with the wide range of contrast adjustment available, this leaves a lot of room for interpretaion 🙂

 

 

The downside of those choices is that … well … this is an APS-C camera with an electronic shutter. You already know whether this bothers you or not. And the drawbacks of the cameras (low battery life, in particular) are unchanged for now.

And I’m guessing that some older lenses with very pronounced MTF Zone B dips will show lower performance in the edges and corners of the frame. But isn’t that more natural than a dip in performance inside the frame with the edges picking up, as is the case with a full-frame sensor?

Targeted benefits

All camera design is an exercise in compromise. True mono cameras tend to come with a very hefty price tag. In-camera presets are fun but limited in their use. Colour-only cameras cannot replicate the workflow and control that is so dear to real fans of monochrome. Each targets a different audience, and that is as it should be.

Within this segmentation, Pixii hopes to make an experience, that’s virtually indistinguishable from pure mono, accessible to a wider audience, based on price and convenience considerations. If you’ve always wanted a colour camera AND a mono camera, suddenly the price – and weight – of each has been cut in half.

Possibly even more important is the commitment to bring fresh air to the photo world. New ideas, chief among which is upgradability. Today’s buyers get 26 high-performance megapixels (a sweet spot, for many users,) storage for up to 3500 RAW files (or over 15 000 in compressed RAW,) and a much more responsive user interface. While the technical evolution since early models is to be expected, the real news is that all buyers of early models can update to later specs, and some have.

   

What is that workflow thou speakest of?

It feels like a fair question, given the importance given to it in the narative of all monochrome cameras. Not being a true specialist, I’ll give you my perception of it.

Flow is that moment when you are focused on “seeing” stuff. Photos come to you naturally, subjects you would normally not have noticed, seem to pop in front of your eyes. When in this state, time flies by, and any exterior intrusion will snap you out of it. In the work place, experts reckon is takes 20 minutes to get into that state of flow, and that we get interrupted (phone, meetings, tchat, noise …) so often that most of us never experience this state of great productivity. But once you have, you know for sure.

In a monochrome context, this means focusing more on quality of light than on a subject. The cat below isn’t interesting because it’s a cat, but because it’s black on a white background. The railings are interesting because of the same tonal reason. It takes time to switch from subject focused to light & pattern focused. That’s where pure mono cameras shine. Since you have no other choice, you get really good at it. In PP, this means you focus mainly on various forms of contrast as your only tools.

 

 

What’s in it for you?

As mentioned previously, you now essentially get two cameras for the price of one. If you’ve ever been tempted by a mono camera but aren’t willing to spend big for it, this is a rare opportunity. If you’re drawn to a greater integration with your smartphone and social sharing than most cameras offer, you could be interested too.

But, to me, the greatest differentiator is the upgrade path. When Tesla updates cars via the air, it always sparks joy among owners. A similar effect is at play here. When I reviewed the 26Mp version of this camera (still with slow innards) I claimed that the main benefit was the proof-in-the-pooding of the reality of the upgradability claim. Further improvements have happened since, and now this. So the small credibility regarding upgradability is now firmly established.

 

 

This monochrome mode is the very first item I can reveal from a stream of equally interesting features, that will all be available to cameras bought before their release. To me, that’s a change of philosophy in the market that’s really worth noting, and deserves to be saluted, whether you intend to purchase a Pixii or not.

Fresh air indeed!

Let me leave you with a few more samples made at various times of the day. The camera was only with me for a couple of days before heading for review duty, so this is all I can provide for now, but more will come 🙂

If you are interested in more information, the official Pixii monochrome page await your visit 🙂

(*) Note that this feature has been available on some cameras for a little while now, Pixii are simply annoucing it to a wider audience, and implementing a switch in the app, at this stage.