Traduzione (inglese) della presentazione di Kazuto al CP+ 2016.

[Italo]

Interessante per capire la strategia Sigma e le scelte tecniche fatte sui nuovi prodotti... ci sono anche dettagli, forse non noti, sulle mirrorless e sugli obiettivi.
Cortesemente tradotto da Katate (utente Sigma forum DP review): http://www.dpreview.com/forums/thread/3975472

Qui un piccolo assaggio:

I’d like to answer your questions, so the first one is “Why mirrorless?” We started the project thinking what the best way to make use of the advantage of Foveon X3 sensor is. We organized the characteristics of DSLR and mirrorless system. I’m going to talk about which is better, but it is only a general opinion. There would be a counterargument, but please accept my explanation as a generalization. Please do not fist fight here to decide which is better (laugh).

For the finder quality, I think the DSLR is better. I’m a kind of classic person, so I prefer the optical finder. For AF speed, there would be several arguments, such as movie or wobbling, but generally speaking, DSLR’s AF is faster than the mirrorless. For AF accuracy, on the other hand, mirrorless is more accurate because the focus is decided by the image sensor which takes the image. For DSLR, AF is decided by a sensor below by measuring the reflected light from the mirror. I would not say that it doesn’t focus, it’s just a disadvantage. If I emphasize too much, some big companies might complain to me, so it focuses, but it’s a disadvantage.

For AE, the mirrorless is more accurate, because it also uses the same image sensor. For the mechanical shock, the mirrorless also has an advantage. This is actually a critical issue. There is not much difference on focal plane shutter for DSLR or mirrorless. But the movement of the mirror is a big difference. The latest DSLR’s mirror is much better, so the shock has become less little by little. But basically, mirrorless has less shock.

For reliability, DSLR is superior. It has a long history, accumulating users’ feedback for decades. These feedback contains the users’ critical experiences, so it becomes really stable. I wouldn’t talk about SIGMA DSLR (laugh), it’s just a general opinion. I won’t say that SIGMA DSLR is reliable because you might say I’m a liar.

Anyway, we organized these points, and concluded that mirrorless would suit more for the Foveon sensor. Foveon sensor is high resolution sensor, and at each pixel, it can resolve the objects. So a small divergence of AF or a small shock of the mirror deteriorates the image quality. It stands out more than Bayer sensor. You will be dissatisfied after comparing an accurately focused image and an off-focused image. Someone who has dp series might have already experienced this.


Here is an image of our new sd Quattro. If you think that this is a mirrorless camera, you might think that it’s a little bigger or heavier. On Gizmodo.jp, it says “sd Quattro, a thud,” “thick,” “heavy,” or “different from the image.” And I think these are true. Only the word “mirrorless” has widely spread without our explanation, many people misunderstand the camera. So I feel sorry.

You might say “sd Quattro is bulky and heavy.” But we chose the mirrorless system not to pursue the compactness. We chose the mirrorless because it has less shock, and the AF is more accurate. The concept is “SIGMA camera with an accurate AF!,” what the hell the concept is (laugh). But anyway, even with a F1.4 lens, the AF is always accurate.......


....... The first is the color accuracy improvement, which is the same as dp Quattro’s I’ve explained before. The second is the EVF. To be honest, the Foveon sensor is not designed for movie. The quality of the EVF, such as the resolution, is not as good as the current mirrorless cameras’. However, the critical factor of the EVF is the delay time of the display. We’ve worked hard on this, and the delay time is 30-45ms, which is not inferior to the current mirrorless cameras. Even the resolution is not so high, the delay time is smaller. Comparing to dp Quattro, this speed is 40% faster. We’ve also worked hard on improving the super sensitivity. sd Quattro is one stop better than dp Quattro.

The price is completely unforeseeable. The image sensor cost is not sure. As the number of the sensors is small, the price will become really high. There will be a price gap between these two models.

Visto che i sensori delle DPQ e dalla SDQ sono della stessa dimensione e numero di pixel, non è chiaro se sia lo stesso sensore.... ma questo singolare "The image sensor cost" credo si riferisca alla sola versione "H", per cui non si sa nemmeno se la "improved sensitivity" sia dovuta ad una diversa tecnologia del nuovo sensore o ad un artificio hw/sw comune alle 2 versioni.   

[Sardosono]

Ho letto l'intera traduzione della lunga presentazione ed è tutto molto interessante e conferma esattamente quello che abbiamo detto tante volte sul forum, compreso il fatto che le SDQ sono mirrorless NON per la compattezza ma per tutti gli altri vantaggi che si ottengono eliminando lo specchio e con lui tutti i problemi che si porta appresso.

Quanto al sensore, a un certo punto dice chiaramente che quello montato sulle due SDQ è lo stesso, tagliato in due differenti misure, quindi stessa tecnologia, stesse dimensioni del pixel e pertanto stesso rapporto di rumore. Che sensore e processore siano anche gli stessi delle DP Quattro non lo dice esplicitamente, questo è vero, ma ritengo che se ci fosse stata una nuova versione, del sensore o del processore, non avrebbe assolutamente mancato di sbandierarlo neanche se l'avessero legato puntandogli contro una pistola, quindi secondo me non ho alcun dubbio che tutto l'hardware è proprio lo stesso identico delle DP Quattro. Di conseguenza se ne deduce che i miglioramenti di cui parla sono perciò dovuti esclusivamente al software.

Anche se per la SDQ H dice che il prezzo non è ancora neanche ipotizzabile, in un altro punto poco prima dice però chiaramente che "I hope the SD Quattro APS-C will be released before summer: the price is not decided, but I want it to be affordable." Ricordando che anche per l'uscita delle DP Quattro aveva usato lo stesso aggettivo "affordable", si potrebbe sperare che possa essere circa equivalente, quindi un poco sotto i mille euro.

[Italo]

A conferma di quanto già scritto da Antonello....  pubblicata solo ieri l'intervista di Imaging Resource a KY al CP+ 2016. http://www.imaging-resource.com/news/2016/03/26/sigma-interview-cpplus-2016-surprise-mirrorless-debut-future-of-f1.8-zooms

Supposizioni dell'intervistatore sui motivi della scelta del tiraggio SA nelle SDQ non confermate in modo specifico nella risposta di KY:

DE: So it’s really full-frame lenses only. Can we discuss the tradeoffs in going with the existing SA lens mount, versus one with a flange-back distance that's been optimized for mirrorless cameras? I mean, we realize that a new Sigma camera needs to be natively compatible with Sigma's SA lenses, but would an adapter approach have allowed you to develop smaller lenses for the system in the future, that would still be compatible? Or is it more that the oblique angle required by the short flange-back distance isn't compatible with a stacked sensor design like the Foveon technology? If you have a three-dimensional structure on the chip and you have a very short flange-back distance, unless the lens has been designed to be telecentric, you can end up with shading or color problems, or whatever. What can you say generally about the decision to go with the SA-mount?

KY: We simply wanted to support our existing customers. They use SA lenses, so we needed to develop a camera that an existing customer can use as-is.

Migliorata nelle SDQ la resa Hi-ISO di circa 1 stop grazie ad un nuovo algoritmo ma la tecnologia dei sensori è la stessa della precedente serie Q:

KY: It has the same pixel size, so it is the same. But for the sd Quattro we changed some algorithms in the image processing, so we could improve the high ISO performance, by maybe about one stop.

DE: Ah, about one stop - and that's as a result of processing, as opposed to sensor design.

Sembra che l'autonomia delle SDQ, senza Battery Grip, sia 1/3 di quella di una DSLR:

DE: Ah, OK. Do you have any idea what the battery life might be? Because you have a battery grip that adds two batteries, so with three batteries do you think the battery life would be comparable to a DSLR...
Sigma's PG-41 Power Grip accessory for the sd Quattro-series cameras will triple battery life, thanks to its provision for not one but two extra batteries beyond that in the camera itself.

KY: Compared to the other companies' battery life, probably [it will] be shorter [per pack], but we're still working on the firmware, so we still don't know.

DE: As, so you may be able to reduce the power consumption. And would the sd Quattro with the three batteries be similar to an SLR with just one?

KY: Probably, yeah.

Lo zoom Art 50-100/1,8 dovrebbe uscire sul mercato con una quotazione attorno a 1300 $.

[sabbiavincent]

Mi pare interessante.