#996. That Sony curved sensor. Great news?

Five years ago, I would have begged to have such a sensor in my camera. How about today ?

 

 

Several readers have sent me the news about the new thechnology. Curved sensors, at last, seem to be ready to take a giant leap from the realm of tiny dimensions into the hairy-chested kingdom of digital medium format.

As a life-time lover of optics (I built telescopes as a hobby as a teen and would have studied in a French engineering school called SupOptic, had my grades been significantly less subpar), the news should really excite me. And, on an intellectual level, it does.

A spherical lens, by its very nature, wants to focus on a curved surface. It takes a lot of design effort to actually make it focus on the plane surface that is a film or a sensor. This effort entails an optical formula that employs numerous optical elements and, now that technology allows it, aspherical designs.

 

 

So, in theory, using a curved sensor will yield the following end user benefits :

• Faster lenses. Just like chromatic aberration, field curvature is cured by closing down. With a curved field, there’s no need to. We can now imagine an f/1 lens that will be almost as sharp wide open, over the whole field, as at f/8.
• Lighter lenses. Because all of the optical train used to flatten the image will not be necessary, 12 element lenses could become 8 element lenses, or less.
• For the same reasons, we can expect cheaper lenses. This could make medium format accessible to a much wider range of users.
• And because there should be no need for aspherics, two extra benefits arise : one is better quality control. Since a sphere is a sphere is a sphere whatever way you turn it, alignment tolerances for spherical lenses are much easier to achieve than when your design contains extreme aspherics.
• And also, as the Milvus 85 abundantly proves, the look from all spherical designs is easier to make gorgeous.

As you can see, the concept is fantastic and exciting! Kudos Sony.

   

You’re expecting a … but! Here is comes. Or, rather, here they come 😉

The first one is slightly unusual, for Sony. But, could this be a little too late? Digital medium format is now a mature game, with well established players and heavily invested users. It’s gonna take a lot of IQ to make me take a big hit on my 5-lens Hasseblad setup, for example (and something tells me, I’m one of the less heavily invested MF users out there … ).

Not once, since the X1D has been with me have I thought “hmm, I wish this thing had better IQ. I wish the sharpness was better, or the colours were prettier, or the corners were this and that”. Hassy has refined its offering to a point where seeing much better IQ anywhere feels a little bit like science fiction, to be honest.

So, does this leave people using high-end full frame cameras and wanting to trade up, as the only candidates? I would have thought that most who want to and can already have. And, if they haven’t, how is an unproven system with few lenses from a manufacturer with no presence in that market going to change that?

   

The second but is … well … Sony.

Calm down, maybe you love Sony. I sure did at some point in my life. But everything I’ve been able to read in the way of statements from Sony officials, about this sensor, points to the Sony trait that displeases me most: technicality.

A curved sensor, on top of the numerous aforementioned benefits, presents its corner pixels squarely to the lens, rather than at an angle. That’s great for two things: no smear from legacy lenses (sorry, can’t help being silly), and less vignetting. Which, frankly is nice to have. Particuarly if you then add one of the dozens of specialty lenses that seem to pop up every week with a vintage look and 2 stops of vignetting (oops, sorry).

The other benefit is lower dark current noise. Excellent on paper. In real life, I wonder how many of the 2.4 billion photographs taken since I started writing this post, actually suffer from excessive dark current noise? Just asking. More seriously, Sony have become masters of the technical aspect of photography. Power to them. But I find the argument less and less compelling, given where the market has arrived today.

 

 

The third but is an elephant in the room. Maybe it’s too early to judge but the initial list of lens patents starts at an equivalent focal length of 52mm. What’s that about? I see two options (let me know if you know more about this)

Option 1: Giv’em some time, already. Yup, sure. Sorry. Personally, I’d have sold the curved sensor with a 28-40 Tri-Elmar type fixed lens, so who am I to complain? It just seems a little odd to start at the long end of the range, where field curvature is much less of a problem …

Option 2: It’s not that easy to start afresh on a wide angle design that doesn’t match the sensor’s curvature. Of course, Sony’s engineers being as talented as they are, will produce excellent wide angle lenses for the system. But maybe a slightly curved sensor doesn’t make that big a difference in wide lens design compared to a flat one. We’d be back at square one: too little too late?

   

Maybe I’m not being fair to Sony. The curved sensor is a great engineering achievement and, 18 months ago, it would probably have been ebough for me to hold my horses and not jump to Hassy before evaluating the final product.

Still, though.

When Mandler was head of design at Leica, the characteristic wave in the lens MTFs showed how difficult field curvature was to correct. A few years ago, the harshness of most well corrected lenses outside the Zeiss stable, showed how difficult it was to do so at an affordable price and with decent rendering. Now, though … If you want affordable excellence in a Sony package, the GM lenses and the Milvus range give it to you in spades.

 

 

What this new camera could bring to the market is Sony’s typical high speed capabilities. As meaningless as this is to me, I understand it speaks volumes to others.

And, let’s face it, this is Sony. So the camera will over-deliver. Over the last few A7x releases, Sony have repeatedly improved both hard skills and soft skills in leaps and bounds. And their strategic department has proved over and over again how well it can read and dominate this crumbling market. In the end, the camera could even overshadow the tiny incumbents in the medium format corner of it.

So, it’s all about bringing more pixels, more ISO and higher MTF to an arena that’s already suffoctaing from its overly technical biases, well, meh … as far as I’m concerned.

However, if this highly symbolic sphere signals the organic reboot the industry so desperately needs (it certainly has all the ingredients for that), then I sincerely wish Sony the very best of success !!

 

 

We shall see and I will be watching keen eyes. Who here might consider this as their next camera? Who’s excited? Who thinks it’s just another tech trick? Who thinks it’s a revolution? Who’s having a curved ball?

Completely unrelated but … final call for Bayhem Challenge !!