[Kunzite]

No, I don't. I am totally enamored by the precision and silence that (especially) linear motors bring to photography. I just hate the feeling that the lenses that have them will all end up in a landfill far quicker than what came before. (At least we won't be sitting around talking about how to de-yellow those with UV in 50 years!)


I would also like to point out, in the OP's favor, that Pentax's adherence to mechanical iris control probably hastened Sigma's and Tamron's dropping of the K mount. Pretty much everything they make these days is electronically controlled. If Pentax had gone KAF4 earlier, that might not have happened. (That may be total BS, too, but it least there's logic in it.)

Well, I do hope they'll make these lenses - at least the higher-end ones - as long lasting as possible. Perhaps we should ask some Canon old timers about their older L lenses...
OTOH the mirrorless crowd predicts the death of DSLRs in 5 years (they didn't change the 5 years, right?) and Pentax is perpetually doomed

While I don't think it would have stopped Sigma from giving up on Pentax, I agree that it probably hastened the process.

[stevebrot]

However much some folks might appreciate the potential benefits of KAF4 and lenses with full electronic control (I think I do), some - not least, previously agrieved SDM-driven DA* lens owners - also feel that the more technology you place inside the lens, the more there is to go wrong with it - and if the components are proprietary and/or have a limited production scale and lifecycle, future repairability - which is almost certain to require service-center involvement - might be less assured (then again, it might not... but we don't know). Of course, that same problem already exists with camera bodies. With KAF4, it may be increasingly relevant to the lenses too.

There is also the tendency to conflate KAF3 with KAF4. KAF4 is specifically movement of aperture control into the lens. It has nothing to do with SDM or PLM or the foibles/excellence of either motor system. I personally consider KAF4 to be a good thing, particularly in regards to encouraging 3rd-party lens support (assuming reverse engineering is possible).


Steve

[BigMackCam]

Yes, but I hoped it won't go as far as to the old Takumars...
After all, when discussing what Pentax could/should do, that is about products they can competitively sell; the diminishing number of such old lenses and the joy they bring to a diminishing number of us is irrelevant.

Sure. I agree

It's too bad we're letting the very first SDM lenses form our opinion about in-lens motors in general.

The KAF4 aperture... I hope they're standardizing to a few sizes. And I'm not expecting too many failures... as the 2 KAF4 lenses we have so far aren't particularly prone to aperture failures.

I know... but I understand why. If these had been consumer-grade lenses, the issue may not have had such a significant impact... but when your $1,000+ DA* premium lens develops an AF fault that, it turns out, is pretty much common to the line, you're likely to remember that... especially if you have to have it repaired a second time - and then, some of those lenses are still current. It didn't stop me buying the DA*60-250/4, though, yet the possibility of SDM failure is always somewhere in the back of my mind Still, I have plenty of other lenses - like the DA20-40, Sigma 17-50 f/2.8 HSM and numerous A-mount models (including a few Tamrons) - that use in-lens motors, and they've been utterly reliable for several years. I'm hopeful that Ricoh has the in-lens AF motor thing sorted, but I remain just ever-so-slightly cautious for the time being.

Lack of progress cost more, I'd say. For example, the slowness with which they migrated towards in-lens motors... how many people were put off, when their first contact with a Pentax DSLR was "screeeeeech! screeeeeech!"?

I agree, lack of progress costs more - and I want to see Ricoh making strides to technologies that younger folks expect. In that sense, KAF4 is pretty much essential, IMHO.

I will say, my first DSLR was a Nikon D40X, and I had but two lenses - a Sigma 18-50 and Sigma 50-200 (I think); both with in-lens AF motors. I fondly remember switching to a Pentax K-7 and the DA18-55 + 50-200 WR kit lenses. The funny thing is, I was never put off by the screw-drive. I'm not saying others weren't / aren't. But it never bothered me, and still doesn't. Go figure

Say Pentax would launch a camera with very good video capabilities; what if it cannot properly control its aperture on a KAF3 lens?
And perhaps Sigma would've launched a few more lenses for K-mount if they had KAF4 figured out, years ago.

Yep. Like I say, I'm all for KAF4 - it makes sense in keeping Pentax relevant, while the precision, functionality and performance will undoubtedly benefit many existing and future customers.

But you'll need to cut me a little slack for wanting backward compatibility with mechanical diaphragm control and screw-drive AF. No matter how much I might want new lenses, I don't want them at the expense of my existing ones

[BigMackCam]

There is also the tendency to conflate KAF3 with KAF4. KAF4 is specifically movement of aperture control into the lens. It has nothing to do with SDM or PLM or the foibles/excellence of either motor system. I personally consider KAF4 to be a good thing, particularly in regards to encouraging 3rd-party lens support (assuming reverse engineering is possible).

Of course, you're right, Steve - and I was aware of that, but guilty of mixing the two in this discussion, largely since the move to KAF4 seems to be concurrent with a shift towards in-lens AF motors. My point regarding increased complexity applies to all in-lens systems mechanically de-coupled from the body. But, increased complexity aside, I do see the benefits.

[Kunzite]

I know... but I understand why. If these had been consumer-grade lenses, the issue may not have had such a significant impact... but when your $1,000+ DA* premium lens develops an AF fault that, it turns out, is pretty much common to the line, you're likely to remember that... especially if you have to have it repaired a second time - and then, some of those lenses are still current. It didn't stop me buying the DA*60-250/4, though, yet the possibility of SDM failure is always somewhere in the back of my mind Still, I have plenty of other lenses - like the DA20-40, Sigma 17-50 f/2.8 HSM and numerous A-mount models (including a few Tamrons) - that use in-lens motors, and they've been utterly reliable for several years. I'm hopeful that Ricoh has the in-lens AF motor thing sorted, but I remain just ever-so-slightly cautious for the time being.

I agree; but except for the early-SDM fiasco, Pentax' in-lens AF motors are quite reliable.
Slight caution is fine - although KAF4 is what, more than 3 years old? We should also have the advantages in mind, including better prospects at Pentax surviving

I agree, lack of progress costs more - and I want to see Ricoh making strides to technologies that younger folks expect. In that sense, KAF4 is pretty much essential, IMHO.

It is.

I will say, my first DSLR was a Nikon D40X, and I had but two lenses - a Sigma 18-50 and Sigma 50-200 (I think); both with in-lens AF motors. I fondly remember switching to Pentax and the DA18-55 + 50-200 WR pair. The funny thing is, I was never put off by the screw-drive. I'm not saying others weren't / aren't. But it never bothered me, and still doesn't. Go figure

Ha ha! I wasn't bothered with my DA Limiteds being screw drive either.
But somehow I decided, when going FF, that I won't buy a screw drive lens again.

Yep. Like I say, I'm all for KAF4 - it makes sense in keeping Pentax relevant, while the precision, functionality and performance will undoubtedly benefit many existing and future customers.

But you'll need to cut me a little slack for wanting backward compatibility with mechanical diaphragm control and screw-drive AF. No matter how much I might want new lenses, I don't want them at the expense of my existing ones

As I said earlier, backwards compatibility is a given - for now at least (and hopefully, for as long as Pentax K last). As much as I am pro-KAF4, I'm also pro-backward compatibility.
Launching KAF4 lenses doesn't mean lack of body support for mechanical aperture couplings and screw-drive AF - you know they (re)launched such lenses just last year...

[BigMackCam]

Launching KAF4 lenses doesn't mean lack of body support for mechanical aperture couplings and screw-drive AF - you know they (re)launched such lenses just last year...

Yeah... I bought one - the HD FA35 f/2. Old habits die hard

[Rondec]

I certainly do! It's just that I also see the benefits of more simple/simplified systems. Not for everything (sports for one), but for many, many uses.

No, I don't. I am totally enamored by the precision and silence that (especially) linear motors bring to photography. I just hate the feeling that the lenses that have them will all end up in a landfill far quicker than what came before. (At least we won't be sitting around talking about how to de-yellow those with UV in 50 years!)


I would also like to point out, in the OP's favor, that Pentax's adherence to mechanical iris control probably hastened Sigma's and Tamron's dropping of the K mount. Pretty much everything they make these days is electronically controlled. If Pentax had gone KAF4 earlier, that might not have happened. (That may be total BS, too, but it least there's logic in it.)

I don't really buy that.

The issue is that there just aren't enough Pentaxians and we don't buy third party lenses enough to make it worth their while. The F mount at least till recently, still used mechanical aperture linkage and Sigma and Tamron held their noses and designed their lenses for that.

Regardless, I think having quiet and smooth action in your lens is a selling point for many people and Pentax is wise to move in that direction, even if Pentaxians still enjoy their screw drive lenses with mechanical apertures.

[Kunzite]

Tamron and Tokina dropped off the K-mount ages ago, so this is only about Sigma. And, IMO, it's only about the very slim chance of Sigma possibly launching just a few more K-mount lenses; because as you say, there were just too few of us buying.

Sigma started offering lenses with electromagnetic aperture for Nikon in 2016, and that meant stop game for Pentax - they weren't going to alter their designs to accommodate the mechanical aperture linkage.
If they had KAF4 figured out... maybe, just maybe...
But they didn't release lenses like the 50mm Art, so I guess they already abandoned Pentax at that time.

[Jonathan Mac]

Sadly, I think you're right. Progress - and it is progress, for sure - comes at a cost, but so does a lack of it.

I can live with - and benefit from - new lenses having electronically-controlled diaphragms, in-lens motors and even focus-by-wire (despite the fact that there's greater complexity and more to fail within the lens). I just hope Ricoh continues to maintain backward compatibility with old glass by retaining in-camera electro-mechanical diaphragm control and screw drive for future Pentax bodies. I'm rarely one to use the term "deal breaker", but lack of those facilities would be just that for my purposes (and I'm nowhere near octogenarian status yet... I have thirty years to go, if I make it that far )...

I agree. The more there is miniaturised and in the lens rather than in the camera, the more there is to go wrong. However, companies can't get too left behind or people will jump ship.

If Pentax doesn't maintain compatibility with both screw-drive AF and mechanical aperture control then I would never buy another Pentax DSLR because without those things I can use my precious DA Limiteds just as easily, if not more so, on a mirrorless system.

[stevebrot]

Tamron and Tokina dropped off the K-mount ages ago

Not our experience here in the U.S.. 2019 is when the bulk of available Tamron product for K-mount disappeared from from the shelves and even then, some models are still available (28-75/2.8 AF09, SP 10-24/3.5-4.5 AFB001, and 17-50/2.8 AF016) with another absent, but still official product (SP 90/2.8 Macro 272E).


Steve

[luftfluss]

Canon has been making lenses with in-lens motors and in-lens IS for some 30 years and they've proven to be durable.

[ThorSanchez]

I agree. The more there is miniaturised and in the lens rather than in the camera, the more there is to go wrong. However, companies can't get too left behind or people will jump ship.

If Pentax doesn't maintain compatibility with both screw-drive AF and mechanical aperture control then I would never buy another Pentax DSLR because without those things I can use my precious DA Limiteds just as easily, if not more so, on a mirrorless system.

What are there... three KAF4 lenses? At one or two lenses a year it'll be 2030 before Pentax could realistically make a body without a mechanical aperture coupling. There are more lenses with built in focus motors, but large swaths of the lineup would be excluded (most notably the Limited primes).

[Kunzite]

What are there... three KAF4 lenses? At one or two lenses a year it'll be 2030 before Pentax could realistically make a body without a mechanical aperture coupling. There are more lenses with built in focus motors, but large swaths of the lineup would be excluded (most notably the Limited primes).

Yes, it would take a while until they could start dropping support for screw drive AF - for the mechanical aperture coupling, much longer. Assuming they want to drop support, which is likely not true.
Backwards compatibility is a given, for the foreseeable future.

As for reliability... there's a thread about broken gears in Limiteds.

[stevebrot]

As for reliability... there's a thread about broken gears in Limiteds.

Yep...three reports in four years, two FA 43 and one FA 31. The most recent reporter indicated the part was readily available and not expensive.

Broken gear in autofocus | PentaxForums.com


Steve

[Kunzite]

I'm not saying it's bad; just that perhaps the difference from well-made KAF4 lenses isn't that big. In reliability, because in other aspects...