Sigma starts a mirrorless system, Olympus FF rumors and some thoughts on mirrorless camera design

Sigma starts a mirrorless system, Olympus FF rumors and some thoughts on mirrorless camera design

There are rumors surrounding some recent Olympus patents, concerning lenses capable of covering the full 35mm size sensor . There are currently patents filed for a number of prime lenses, all at very bright (f/1.4) apertures.

Now, this is certainly not a direct indication that Olympus is "going full frame". Companies apply for patents all the time; sometimes it's only for the reason of "locking" a particular optical design (for lenses) or an idea for a camera component (e.g. an autofocus system). Indeed, we have seen patents from Olympus during the last several years that led to nothing in actual production.

Some people have speculated that Olympus plans on producing lenses for the Sony FE mount, while others are seeing this as an indication of a possible future Olympus FF system. It has to be said, the current economic situation doesn't leave a lot of optimism for the latter; although we have to entertain the possibility. Olympus could differentiate with their own FF system and provide an alternative to Sony, as well as a compliment to their m43 line-up.

Let's stay with this speculation for a while. I admit I want to use it as an excuse to discuss future mirrorless designs in general. Supposing Olympus makes their own FF system, one of the major initial decisions would be what mount to use.

Since this is a completely new system, they have the privilege to go with an entirely new mount.  Of course, they already have a "full frame" one, the old OM film-era lens mount. This way one could possibly use older OM lenses (some of which are optically excellent, even by today's standards) as a stopgap until the native lens lineup is fulfilled.

But the OM mount features a long flange distance, you say. OK, let's discuss how much of a problem this is.

Sigma recently entered into the mirrorless system camera market, their first foray being a couple of cameras named Sigma SD Quattro; one with a APS-C Foveon sensor and one with -surprisingly- a larger APS-H one. Of course, one of their priorities was to cover their existing, albeit small, Sigma DSLR user base. As a result, they used the same Sigma mount found in the older SD cameras (which is approximately the same length as Canon EOS).

The SD Quattro is an unusual looking camera, but that's not news coming from Sigma; their Quattro mirrorless compacts were also peculiar looking beasts. With the SD Quattro, they used a quite large handgrip, which offsets the protrusion needed to fix the flange distance for existing Sigma lenses. In fact, the mount protrusion goes as far as the grip, which gives a somewhat square appearance.

Sony went exactly the other way around with their FE mount. Since they wanted to retain compatibility with the APS-C E-mount, they kept the exact same flange distance. This resulted in smaller bodies (the a7 is in fact about the same size as the m43 Olympus E-M1). But what about the lenses?

If you look into the latest fast Sony glass, the G-Master line, they are as large or larger than equivalent DSLR lenses. Other FE lenses are not smaller also: compare for example the 55mm f/1.8 with any Nikon or Canon lens at the same focal length and max aperture. You can't fight the laws of optics: with the flange distance being short, you have to design a longer lens (particularly behind the rear element) to be able to cover the given sensor size. An easy way to see how this works, is to compare Samyang lenses, which are otherwise completely identical (optically speaking), for different systems: notice how much Sony FE versions differ in length.  

Thom Hogan made an interesting observation when discussing the Sigma announcement. His view is that, the added grip balances the camera nicely, and there is no need to make a shorter register mount, for a new (full frame) camera system. This also serves as a nod to Canon and Nikon. Should they decide to enter the mirrorless system market in earnest, all they'll have to do is work around a similar concept. Their existing lenses would work right away, and newer versions, optimized for mirrorless, could follow.

I have to say, I agree to this design philosophy. We have to, finally, put the argument about mirrorless being "for smaller size and weight" to sleep, once and for all. Mirrorless is not about smaller size in itself, it's about an improved imaging technology in general. Cameras can be smaller, if needed. They can also be optimally designed around the sensor size; no need for huge DSLR concepts when you have a smaller m43 or APS-C sensor. Olympus/Panasonic and also Fuji made this crystal clear: their lenses are designed from the ground up to cover the particular sensor size they use.

Nikon D750, Sigma SD H Quattro and Sony a7ii size comparison, all fitted with 85mm f/1.4 lenses.
As you can see, the Sony is actually a tiny bit longer front-to-back than the Nikon DSLR. The Sigma is about the same, if you ignore the protruding viewfinder eyepiece. As seen on the Sigma, the mount overhang can potentially be used to accomodate extra controls for the camera, it's not like a dead weight "dummy" adapter.
Also note the rear element protrusion on the G-Master lens, fitted to fix the flange distance for the E-mount.

Some people come to mirrorless for the reduced size and weight, and that's absolutely fine. Most of the time, they just don't care to use a larger-sensor camera at all, which is also fine. On the other hand, those in need of a more professional camera body, soon find out you can't so easily have your cake and eat it too.  Heavier lenses demand a larger grip, and there are also other considerations regarding a larger body, when used under more demanding situations.

Returning to the Olympus rumor, yes, I'd like them to make an OM-mount FF camera, if they make one at all. The larger body could accommodate larger lenses easily, although I believe most of the primes would actually not be  that bulky after all. It could also be easier to fit larger batteries (an open wound for most mirrorless cameras in a professional environment) and possibly avoid issues such as overheating with video. Does this ring a bell, Sony?

For those worried that future mirrorless designs may become behemoths, and for the few DSLR-luddites who will think "we told you so, all along": no, and emphatically no. A brand new, from the grounds up design can be exactly what it needs to be. It has to plagiarize nothing. All it has to be is ergonomically correct and to not create design bottlenecks for the future of the system. As evident in current cameras: the Olympus E-M1 and Panasonic GH4 are "large" regarding the sensor size, but they are exactly what's needed for the tasks they normally carry. On the other hand, the Sony a99 is the smallest full frame "DSLR", but a lot of Sony users refuse to abandon it in favor of the a7 line.

In conclusion, my belief is that, as soon as the notion of "mirrorless for small size" is abandoned, we will see the true potential of mirrorless technology. Rather, the idea of "mirrorless for the particular size/function/features needed" should become the new motto.


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