[Nicolas06]

Assuming anything... makes us into donkeys.

But since we're playing that game my thought is updated to hd coatings, wr, rounded blades, nothing else.

Well the old FA had aero bright coating that is an higher end coating than HD. The new DFA* have aero bright II... I would expect the FA ltd to get the aero bright II, not the great but less high end HD coating.

But yes rounded blades and better coating are truely possible. Quick shift may be possible too. Or WR.

I don't think DC is possible without changing the optical formula... When you change the way you focus, you usually need to change the lense design to adapt to it. That's why Zeiss keep manual lenses, they can keep the best lenses design without compromizing it for AF. If you look neither the ltd nor the 55-300 got DC when updated and the new 18-50 has DC but is a different lense than the 18-55.

So yes, most likely coating and blades.

[bdery]

Well the old FA had aero bright coating that is an higher end coating than HD

I strongly believe areobright was introduced much later than the FA limiteds. According to Photozone, the DA*55 is the first to use aerobright.

I don't think DC is possible without changing the optical formula... When you change the way you focus, you usually need to change the lense design to adapt to it.

It's entirely possible. What changes when you change the AF motor is the barrel around the glass. The glass design is made BEFORE anything else is added.

That's why Zeiss keep manual lenses, they can keep the best lenses design without compromizing it for AF.

It's not because they don't want to change their designs. It's because, first, people are still willing to pay for their MF lenses, and second, because it's easier for them.

Tamron and Sigma make physically identical lenses for many mounts.

If you look neither the ltd nor the 55-300 got DC when updated and the new 18-50 has DC but is a different lense than the 18-55.

That's not proof of anything

[FantasticMrFox]

... and the new 18-50 has DC but is a different lense than the 18-55.

DC must have been the least important factor in the 18-50 having a different optical design - thought about the fact that it's much smaller and retractable?

[monochrome]

I strongly believe areobright was introduced much later than the FA limiteds. According to Photozone, the DA*55 is the first to use aerobright.

Ghostless coating was developed in 1992 for use on Pentax surveillance cameras across Japan. According to a posting here by Blue it was apparently first applied to a SLR camera lens on the FA43 in 1997. Nicolas06 might be referring to Ghostless Coating.

[bdery]

Ghostless coating was developed in 1992 for use on Pentax surveillance cameras across Japan. According to a posting here by Blue it was apparently first applied to a SLR camera lens on the FA43 in 1997. Nicolas06 might be referring to Ghostless Coating.

In that case, I would strongly disagree that ghostless is superior to HD.

[monochrome]

In that case, I would strongly disagree that ghostless is superior to HD.

AeroBright II, on the other hand . . . .

[Nicolas06]

It's not because they don't want to change their designs. It's because, first, people are still willing to pay for their MF lenses, and second, because it's easier for them.

Tamron and Sigma make physically identical lenses for many mounts.

Try to put an AF motor to a M135 f/2.5... Well just turn the focus with your hand and you'll understand why the design would be a misfit for AF. When you use MF, the motor use the fingers whose muscle extend in the forearm. AF on the opposite rely on very small and small power source too. MF design are typically quite different (and also can be more compact) because it is acceptable to move an heavy part of the lense, something that is not feasible with AF.

In body AF motor on Pentax bodies is quite fast and powerfull, it may be difficult to have a silent motor as powerfull inside the lense that is still fast. After all tamron did that on their old 70-200 lense. It has the reputation to be very slow, and it is true for Nikon where tamron added a motor to replace the screw drive but the lense is reasonably fast on Pentax bodies because the in body motor is powerfull enough.

As for sigma they explained that they do not make lenses for Sony mirrorless mount because to have good AF performance using contrast AF need different lenses design and the market is not big enough to justify design dedicated for mirrorless.

AF does affect the optical design because AF is dependant of the focussing group including its size, weight and how much and how fast it need to move. Design that may be easier or have nice optical property but rely too much on a heavy focussing group are misfit for AF. This is even more true for contrast AF. In lense motor also add more contraints.

[monochrome]

AF does affect the optical design because AF is dependant of the focussing group including its size, weight and how much it need to move.

asahi man answered this question. It is possible to have a silent, DC ring motor with enough torque to quickly and accurately turn heavy optics.

Example (Hint?): That doesn't mean the lens barrel design wouldn't need a change to accomodate the shape of the ring motor.

Extending from bdery's comment above, the key factor might well be that people seem perfectly willing to pay $500 - $1,000 +/- for a new FA Limited RIGHT NOW, just as they are, before there is even a FF to mount them on. That fact alone just might encourage Ricoh to leave them unchanged.

[aurele]

IMO pentax does already produces a variant of the Otus 55/f1.4 the DA* 55. (notice the similar rendering characteristics)

Both lenses are very different in the way they are built : optical construction is very very different. Philosophy too.
Otus : The best F1.4 no mater the price.
Pentax : The best F1.4 at a reasonnable price, keeping in mind that f1.4 should remain flatering for the subject.

---------- Post added 19th May 2015 at 11:47 PM ----------

asahi man answered this question. It is possible to have a silent, DC ring motor with enough torque to quickly and accurately turn heavy optics.

Example (Hint?): That doesn't mean the lens barrel design wouldn't need a change to accomodate the shape of the ring motor.

Extending from bdery's comment above, the key factor might well be that people seem perfectly willing to pay $500 - $1,000 +/- for a new FA Limited RIGHT NOW, just as they are, before there is even a FF to mount them on. That fact alone just might encourage Ricoh to leave them unchanged.

Ricoh will probably change de Limited to justify the creation of other lenses : why pay 800$ for a 77 f1.8 when they could probably build a 85 f2 and sell it for 200$. The limited would be barely faster, not necesseraly that much thiner or lighter. Hence, what would justify buying the 77 instead of the 85 ?

[pinholecam]

Marilyn Monroe, James Dean, Jimmy Hendrix, John Lennon - Legendary

See the entry requirements into Legendary status?

[Nicolas06]

asahi man answered this question. It is possible to have a silent, DC ring motor with enough torque to quickly and accurately turn heavy optics.

Example (Hint?): That doesn't mean the lens barrel design wouldn't need a change to accomodate the shape of the ring motor.

Extending from bdery's comment above, the key factor might well be that people seem perfectly willing to pay $500 - $1,000 +/- for a new FA Limited RIGHT NOW, just as they are, before there is even a FF to mount them on. That fact alone just might encourage Ricoh to leave them unchanged.

I will trust it when I see it. Until know I never saw AF lenses like the one leica has for its 35mm range filter system or even like the old M135... Both cover FF image circle.

If the DC motor make the lense too heavy/too big and also more prone to failure on the long run, this is not that interresting.

[monochrome]

I will trust it when I see it. Until know I never saw AF lenses like the one leica has for its 35mm range filter system or even like the old M135... Both cover FF image circle.

If the DC motor make the lense too heavy/too big and also more prone to failure on the long run, this is not that interresting.

OK - then everything you write is speculative, until you see it.

It's all just a bunch of unrelated FUD spreading.

[bdery]

Try to put an AF motor to a M135 f/2.5... Well just turn the focus with your hand and you'll understand why the design would be a misfit for AF. When you use MF, the motor use the fingers whose muscle extend in the forearm. AF on the opposite rely on very small and small power source too. MF design are typically quite different (and also can be more compact) because it is acceptable to move an heavy part of the lense, something that is not feasible with AF.

With older lenses such as the one you refer to, the WHOLE lens moves back and forth. With modern lenses, specific internal elements move back and forth, generally. A much lighter weight to move. In addition, the feeling you get when moving the focus ring is mainly caused by the nice dampening that the designers put there for your pleasure.

In body AF motor on Pentax bodies is quite fast and powerfull, it may be difficult to have a silent motor as powerfull inside the lense that is still fast.

So you're saying it's possible to get decent (some would say, very good) speed out of an internal focus motor in, say, a 60-250, but it would be impossible with a 43mm?

With all due respect, you

That doesn't mean the lens barrel design wouldn't need a change to accomodate the shape of the ring motor.

You phrased it better than me. Thanks.

[UncleVanya]

Well the old FA had aero bright coating that is an higher end coating than HD. The new DFA* have aero bright II... I would expect the FA ltd to get the aero bright II, not the great but less high end HD coating.

But yes rounded blades and better coating are truely possible. Quick shift may be possible too. Or WR.

I don't think DC is possible without changing the optical formula... When you change the way you focus, you usually need to change the lense design to adapt to it. That's why Zeiss keep manual lenses, they can keep the best lenses design without compromizing it for AF. If you look neither the ltd nor the 55-300 got DC when updated and the new 18-50 has DC but is a different lense than the 18-55.

So yes, most likely coating and blades.

HD coating would be on the lenses on both sides not just the aerobright on the front element.

Also Zeiss doesn't make AF lenses due to license restrictions on non-japanese manufacturers.

https://photographylife.com/zeiss-make-autofocus-dslr-lenses

[aurele]

With older lenses such as the one you refer to, the WHOLE lens moves back and forth.

well, absolutely not. The 50 mm for example, only the rear group (3 elements out of 6) moves. this goes for the 35mm f2.4 too, and the DA 40.

On most push/pull zoom, only the rear group or the middle group (if internal focus) moves. That is also the case for some WR lenses, like the DA*55.