[Kunzite]

Fast focusing, ring type USM lenses have focus rings mechanically connected. And talking about good propositions, that would be a similar, ring-type SDM... or that semi-circular DC motor Pentax patented some time ago.

[TomTextura]

I don't think there is much future in AF lenses that do not use focus-by-wire. Whether that will please everyone is another issue.

Well, if Fuji's go at it with the X-Pro is any indication, the focus-by-wire technology is no step forward but rather au contraire, IMHO. Other than being just a tad noisy, I'm not sure what's wrong with any of the Limiteds' focusing. They have fast AF, smooth MF, and only the FAs are without quick-shift. It's really just the zooms in Pentax's line-up that seem to be a bit clunky in terms of AF. As far as I can tell, the main two things missing from Pentax's current AF system, on the camera side of things, are smaller and more AF points. Adding just those, combined with the improved low-light sensitivity of the K-5II and the better tracking of the K-30, would go a long ways in improving their AF system and could meet most if not all of my needs, especially when using my primes. Maybe the upcoming DA Limited and DA* zooms will give us a clue of what Pentax has in store on the lens end of their AF system.

[kenyee]

Nikon's price cuts today (bundling a 24-85 w/ the D600) effectively put the body at the $1500 level. D800 has dropped to $2800.
Pentax has it's work cut out if it's really going to price the new body at the rumored $2300 :-O

[Ash]

$2300 or even $2500 is still a significant saving on $2800. The Pentax FF must perform closer to the D800 level rather than the D600 level for this to be worth it.

[crazy_oam]

Not to eat into the sales of their highly profitable 24x36 DSLR lines.

The same reason (extended to APS-C DSLRs) explains why Canon, Nikon and Pentax were the last to launch a mirrorless camera, far later than Olympus, Panasonic, Samsung and Sony.

Can't agree more.

[Laurentiu Cristofor]

I believe the only current focus by wire Canon lens is the 85/1.2.

The lens I had in mind was the 50/1.4, but maybe it just had the feeling of focusing by wire. When I used it, I noticed that the rotation of the focusing ring didn't quite match the rotation on the focusing scale displayed in that tiny window. And it generally didn't feel like it had a mechanically coupled aperture. But maybe it did and it just felt weird.

The trouble with focus by wire lenses is if the focus motor gives out and can't be replaced, they immediately become landfill material.

Yes, focusing motors add one more point of failure. Image stabilization adds another. That is why I prefer manual lenses and IBIS. But our expectation for lenses to last for ages is based on having used old manual equipment that had such qualities. For the modern customer, this expectation no longer exists. The ability to focus and the brand reputation is much more important.

There have been a number of studies looking at auto focus continuous which showed the K5 to be equal to or better than the 7D and D7000 (this preceded the K5 II release).

The K-5 may very well have AF performance on par with Canon. But the press coverage that you mentioned can only impact French or German users (perhaps such coverage is why Pentax does a bit better in Europe). And the K-5 is not an entry level camera anyway - it has become more affordable now, but at the time when it was getting press attention, it was over the budget of people looking for their first DSLR.

[Laurentiu Cristofor]

I'm not sure what's wrong with any of the Limiteds' focusing. They have fast AF, smooth MF, and only the FAs are without quick-shift.

FA Limiteds are not as smooth as a Takumar (a good condition one). And DA Limiteds are even more challenging than the FAs because they have a shorter throw and are smaller too. If you examine these lens generations you'll see how the throw gets shorter and the friction goes away to allow the focusing motors to work more efficiently. As AF became more important, the considerations for MF faded away. The lens build requirements for AF/MF are mutually exclusive.

Focusing by wire does offer a solution, because it decouples the aperture ring from the focusing mechanism. Yes, you have a new failure point, but failure points have kept piling up in modern technology - AF motors in lenses, IS, power zooms. And look at digital camera bodies - if you want a better sensor, you need to change the whole body - film cameras didn't have such problem, yet they're gone.

[mecrox]

And look at digital camera bodies - if you want a better sensor, you need to change the whole body - film cameras didn't have such problem, yet they're gone.

You'd think this might transform the economics of the business, enabling companies to sell someone three or four digital cameras over a period when they'd probably have been able to sell them just one film camera - and perhaps two or three electronic lenses on the same basis over one old manual lens. But I wonder if it has? Maybe, but perhaps the cost of developing those new cameras and lenses has become so huge that the advantage is cancelled out. Anyway, tough, rugged and built to last these days seems to mean 3-5 years if you're lucky.

[Ash]

It may apply to some lenses also, even DA *cough* star lenses. Longevity once thought of as assumed in lenses (Takumars, M, K , even A) is now no longer the case. Limited lenses however are in a class of their own in this regard. Pentax bodies are well constructed but limited to actuations. Servicing a faulty shutter mechanism will be expensive to replace. Times have changed. We are living in a society basing itself more and more on disposable equipment. I'm glad the Limited lenses are still being made available new - it's one indication for me that Pentax still want to keep their legacy for longevity going.

[Kunzite]

Focusing by wire does offer a solution, because it decouples the aperture ring from the focusing mechanism.

You mean the focus ring.
With "full-time manual" mechanisms, which can be implemented even with screw drive AF, I don't see it as being an issue. On the contrary, I believe that losing the mechanical connection, replacing it with a system that would only approximate the movement induced by turning the focus ring and introducing lag is a step in the opposite direction, and not towards the good old manual focus lenses feeling. At least I didn't liked how the actual systems works (same for EVFs).
OTOH I agree that focus throw could be improved, this way.

[falconeye]

Nikon's price cuts today

That's no price cut but a one time special offer valid for two days only (even Apple does such things once a year). But a very good one as it effectively puts the D600 body at 1250$ only.

[Rondec]

The K-5 may very well have AF performance on par with Canon. But the press coverage that you mentioned can only impact French or German users (perhaps such coverage is why Pentax does a bit better in Europe). And the K-5 is not an entry level camera anyway - it has become more affordable now, but at the time when it was getting press attention, it was over the budget of people looking for their first DSLR.

Well, the web is worldwide and these articles are posted widely on the Pentax forums. Not sure why Pentax doesn't license them for wider user in advertisements. Oh, wait, there are no advertisements.

Rightly or wrongly, almost exactly the same auto focus system as been present on entry level cameras as on the K5. The only thing they lack is a light temperature detector, which wouldn't effect continuous auto focus anyway. With the K5 II, there has been a separation made between the K5 II and the K30 with regard to auto focus -- the K5 II can focus in a lot darker situations than any Pentax camera could to this point.

[TomTextura]

FA Limiteds are not as smooth as a Takumar (a good condition one).

I believe that; the Takumars have quite the reputation. I should get myself at least one before too long. The thing is, with the FA Limiteds you have the best manual focusing of any AF lens that I know of plus the AF isn't at all shabby.

And DA Limiteds are even more challenging than the FAs because they have a shorter throw and are smaller too. If you examine these lens generations you'll see how the throw gets shorter and the friction goes away to allow the focusing motors to work more efficiently. As AF became more important, the considerations for MF faded away.

Yeah, that's probably true too. I have very little experience with the older generations of MF lenses so don't long for their manual focusing performance like many here do. I can sympathize though because at this point I can't imagine being satisfied with any primes that don't match the FA Limiteds, in terms of both focusing and IQ. Satisfaction levels seem to be unavoidably relative to what one knows from experience to be possible.

[northcoastgreg]

The lens I had in mind was the 50/1.4, but maybe it just had the feeling of focusing by wire

As far as I know, the only Canon 50mm lens that used focus by wire was the EF 50mm f/1.0L USM.

Incidentally, it appears that the new Canon STM lenses use focus by wire as well.

Longevity once thought of as assumed in lenses (Takumars, M, K , even A) is now no longer the case. Limited lenses however are in a class of their own in this regard.

Yes, that is right. Which means we don't have to settle for lenses that are disposable products. We can accept the tradeoff of limited lifespan with digital cameras because of the advantages of digital image production over film. But why let that disposibility creep into our lenses as well? The glass in lenses is expensive to make; yet once made, it can, if properly looked after, last a very long time. Since we have lenses that can last a long time but cameras that can't, doesn't it make sense to keep all the failure points in the camera, which will have to be replaced in any case, rather than letting them spread into the lens?

[dankoBanana]

Yes, that is right. Which means we don't have to settle for lenses that are disposable products. We can accept the tradeoff of limited lifespan with digital cameras because of the advantages of digital image production over film. But why let that disposibility creep into our lenses as well? The glass in lenses is expensive to make; yet once made, it can, if properly looked after, last a very long time. Since we have lenses that can last a long time but cameras that can't, doesn't it make sense to keep all the failure points in the camera, which will have to be replaced in any case, rather than letting them spread into the lens?

i agree with this point. The limiteds will work "for ever" because they have no motors and thats their big advantage. The noise of the screw drive AF is tolerable but not for video. But then again, there are SDM lenses and MF. To each his own.
I don't fancy focus by wire too. My first good photo tool was the Canon Powershot Pro 1, a remarkable prosumer that had a 2/3" sensor and L series 7x optical zoom lens ( 28 - 200 mm equiv, f2.4-f3.5) with a swivel lcd and an EVF (with 235,000 pixels). Its only flaw and the reason its not in use today - focus by wire thats been dead for years for wich the service center is asking too much to repair. Isnt that a shame?
fun fact, in 2001. it had an USM motor. Something Pentaxians crave for their lenses in 2012/13 too. Isnt that an even bigger shame?