Thread: Will new X100 S improvements work with X-series lenses?

A bit of a technical question / speculation. Based on the Panasonic 20mm m43 lens and its inability to take advantage of the various technical improvements in m43 bodies over the past couple of years, it makes me wonder about the Fuji 18 and 35mm lenses as the X-system cameras evolve and, presumably, get a lot of the improvements previewed in the X100s announced yesterday...

What I DO know is that lenses with external focussing mechanisms (which the initial Fuji lenses share with the Pany 20 and the first version of the Olympus 17mm) do not respond to faster processing speeds to provide faster CDAF in CDAF-only cameras. Or they do up to a point, but the lens mechanisms quickly become the weakest link in the chain and can only go SO fast. The Pany 20 was a bit faster with the GH2 and subsequent models than it was with the GF1 and G1, but on the new bodies it doesn't even come CLOSE to the focus speeds of the newer lenses with internal focussing, from both Olympus and Panasonic. The initial Fuji X-series lenses share this external focussing mechanism and so I'd expect them to share this liability for future X-system bodies IF those bodies just improved the processing speed of their CDAF system.

BUT...

What I DON'T know is how this type of lens construction interacts with PDAF and whether Fuji's move toward hybrid CDAF/PDAF auto focussing (which I assume they'll port over to future X-bodies). Will PDAF overcome the physical limits of these lenses to a greater extent than faster CDAF would? I know that PDAF doesn't require as much movement of the lens - it goes to a calculated point rather than raking back and forth to FIND that point - but I have no idea how much the physical speed of the lens mechanics limits the potential improvements...

Any thoughts from those with a better technical knowledge than I have?

I like my X-Pro a lot, but I use it about 90% of the time with the 18mm lens. I was anticipating replacing the 35mm with the 23mm when it became available because I almost never use the 35 but I would use the 23mm some - not as much as the 18, but a fair amount. I might have bought the 14mm also but that wasn't for sure - I already have wider angles covered in my m43 gear and I'm skeptical about how well the 14 will work with the OVF given the limits to the width of the OVF view. Now that the X100s has equalled the X-Pro in some ways and leapfrogged it in others, I'm half considering the possibility of selling the X-Pro gear and getting the X100s along with the 28mm adapter. If future X-Pro bodies are likely to bring that system up to that level of performance, I'll probably just sit tight with what I have and add a lens or two to the X-Pro. But if the current lenses are going to notably limit the improvements to come with future bodies, I wouldn't mind going back to the smaller, simpler camera since I don't see myself ever having an extensive lens collection with the X-Pro anyway...

-Ray

Interesting question. It's likely especially important for those that consider the current iteration slow, or are comparing it to a DSLR experience.

Given the outstanding quality of the 35 in particular, and Fujis obvious commitment to the X approach, I would not be shocked if they updated the lens at some point if needed.

It depends on how Fuji implements the hybrid focusing system. For instance, does the PDAF and CDAF work separately or together. With the EOS M and the 650D, Canon stated that the hybrid focusing involved the PDAF determining which direction to go in, and the CDAF was used for fine tuning. In practice it seems that it isn't great. I've also read some user reports that the hybrid focusing on the latest NEX cameras hasn't made a great difference either, but again I personally have no first hand evidence to support that. How Nikon implements the hybrid system on the 1 series I don't know, but they seem to have made it work.

As for existing Fuji lenses, unit focusing lenses like the 35/1.4 will always have a disadvantage because the entire optical group is moved during focusing rather than one or more lightweight lens elements. If the others lenses are internal focusing they won't have the same issue.

On the X-E1 with 35mm lens focusing works much faster and more accurately if you put the camera in manual focus and push the AE-L/AF-L button....based on that, the hardware limits of how fast the 35mm can focus has not been reached during normal AF functions.

Perhaps future firmware releases will work out more kinks.

Originally Posted by tdp

On the X-E1 with 35mm lens focusing works much faster and more accurately if you put the camera in manual focus and push the AE-L/AF-L button....based on that, the hardware limits of how fast the 35mm can focus has not been reached during normal AF functions.

Perhaps future firmware releases will work out more kinks.

That's interesting - I'm not finding that with the X-Pro at all. If anything it seems slightly faster with a half press in AF mode than with the AFL button in MF. But there's not enough difference to worry about. At least in low light - I haven't really experimented in good light, but the AF is more than adequate in good light anyway, for my purposes...

-Ray

I find that C-AF is the fastest as it perhaps has a lower threshold for what a high contrast AF lock is.

It really is a shame though that the 35 is not an internally focusing lens. It's almost perfect in my eyes.

Let's hope the 23/1.4 is internal.

Does the 18/2 and 35/1.4 have internal focusing motors like the 18-55? The AF on the 18-55 is really quiet and smooth. On my XE1, the 18-55 is definitely faster focusing than the 35/1.4, particularly in the wide to mid focal length. At full zoom, it's about the same as the 35, and a tad bit faster than the 60/2.4.

I prefer manual focus on a traditional lens over any autofocus options. I wish the magic of focus by wire was more....magical.

Originally Posted by Armanius

Does the 18/2 and 35/1.4 have internal focusing motors like the 18-55? The AF on the 18-55 is really quiet and smooth. On my XE1, the 18-55 is definitely faster focusing than the 35/1.4, particularly in the wide to mid focal length. At full zoom, it's about the same as the 35, and a tad bit faster than the 60/2.4.

No, the 18 and 35 are definitely clunky, external movement lenses that make their share of noise when moving everything into place. The 18 is pretty fast about it, the 35 notably less so, but they're not internal focus... And no telling how they'll work with future bodies that one would assume would incorporate PDAF...

-Ray

Oh, what I meant was motorized vs. non-motorized. I'm speaking from my experience with Pentax lenses. Some older Pentax lenses were screw-driven lenses that focused via a motor inside the camera body. The newer and more expensive lenses had their own built-in motors. The screw driven lenses always made more noise, while most of the motorized lenses were quieter (although not always faster or more accurate).