[D1N0]

Digital Camera Info have added two lines to their report:

- First K-mount lens to adopt an electromagnetic diaphragm (KAF4 mount)
- Will work with K-70, K-1, K-3 II, K-S2, K-S1. Cameras other than K-70 will need a firmware update. Non-compliant [=other] cameras won't stop down the aperture.

so the K-1, K3 II, K-S2 and K-s1 will also have a KAF4 mount when you upgrade the firmware

[Mistral75]

so the K-1, K3 II, K-S2 and K-s1 will also have a KAF4 mount when you upgrade the firmware

Not even so since they will keep their in-body motor and screwdriver .

As for lenses:

• KAF2 = in-lens motor + focus can be commanded and controlled by in-body motor
• KAF3 = in-lens motor only
• KAF4 = in-lens motor only + electromagnetic control of aperture.

[Reed]

Not even so since they will keep their in-body motor and screwdriver .

As for lenses:

• KAF2 = in-lens motor + focus can be commanded and controlled by in-body motor
• KAF3 = in-lens motor only
• KAF4 = in-lens motor only + electromagnetic control of aperture.

KAF4 Combo then

[Mistral75]

The aperture is controlled and commanded by an electromagnet and not a mechanical device. It's cheaper, more precise and allows for continuous and smooth variation in the aperture, which is a highly desirable feature in video mode.

All Canon lenses have such a device since the first day of the EOS system and so do all recent Nikon lenses (the "E" series).

Having the K mount allowing for electromagnetic control of the aperture is also important because it abolishes a barrier for third-party lens makers (think: Sigma) to produce K-mount versions of their lenses.

Another advantage of building up a portfolio of lenses with light focusing group and electromagnetically controlled aperture such as the 55-300 PLM RE: the day you propose a mirrorless offering, your clients can use these lenses with no drawback whatsoever, either directly if your mirrorless camera uses the K mount (KAF4 actually) or with a very simple adapter (spacer + connectors) if you choose the way of a new mount with a shorter register.

In both cases, your brand new mirrorless offering can rely on a portfolio of lenses from day one.

Clever move from Ricoh Imaging, isn't it?

[D1N0]

Another advantage of building up a portfolio of lenses with light focusing group and electromagnetically controlled aperture such as the 55-300 PLM RE: the day you propose a mirrorless offering, your clients can use these lenses with no drawback whatsoever, either directly if your mirrorless camera uses the K mount (KAF4 actually) or with a very simple adapter (spacer + connectors) if you choose the way of a new mount with a shorter register.

In both cases, your brand new mirrorless offering can rely on a portfolio of lenses from day one.

Clever move from Ricoh Imaging, isn't it?

They're a bit late. They need to bring a mirrorless sooner than in 5 to 7 years.

[Mistral75]

KAF4 Combo then

I'd say KAF2/4, like the famous Aston Martin DB2/4 .

[Doundounba]

the day you propose a mirrorless offering, your clients can use these lenses with no drawback whatsoever, either directly if your mirrorless camera uses the K mount (KAF4 actually) or with a very simple adapter (spacer + connectors) if you choose the way of a new mount with a shorter register.

It makes much more sense if you intend to release something with shorter register, where it simplifies the adapter...

The bummer is this breaks the forward compatibility of older bodies like my K-3 with new lenses. I'd really like to know if all lenses released from now on will be KAF4...

[Mistral75]

(...)

The bummer is this breaks the forward compatibility of older bodies like my K-3 with new lenses. I'd really like to know if all lenses released from now on will be KAF4...

Look at the precedent of KAF3 lenses (not compatible with in-body autofocus motor).

[seventysixersfan]

So it sounds like I shouldn't be in a great rush to sell off my existing smc DA 55-300 zoom to get this new version, if I do not intend to upgrade my K-50 camera body any time soon. Would be nice to get the smaller length and faster and quiet autofocus, though.

[ogl]

Look at the precedent of KAF3 lenses (not compatible with in-body autofocus motor).

But KAF3 works with almost all old bodies. It's compatible with KAF2.

[csa]

The bummer is this breaks the forward compatibility of older bodies like my K-3 with new lenses.

So it sounds like I shouldn't be in a great rush to sell off my existing smc DA 55-300 zoom to get this new version, if I do not intend to upgrade my K-50 camera body any time soon. Would be nice to get the smaller length and faster and quiet autofocus, though.

Yep, I was pretty excited about this new lens; but have no plans on replacing my K3. So it looks like I'll be getting the HD 55-300, presently available in the future, to replace my DA 55-300.

[Mistral75]

But KAF3 works with almost all old bodies. It's compatible with KAF2.

It works but only in manual focus mode if the body doesn't manage the in-lens motor.

A non-functional aperture is worse than a non-functional autofocus, of course.

[UncleVanya]

But KAF3 works with almost all old bodies. It's compatible with KAF2.

SDM only lenses do not work on bodies without SDM contacts - the DA* series has five transition timeline lenses (DA*200, DA*300, DA*60-250, DA*50-135, DA*16-50) that were offered in dual mode (screw drive and SDM) configuration. Every other DC or SDM lens ever made has only worked on SDM enabled bodies. The failures in the aperture control block may also account for some of the desire to move in this direction - it is hard to know for sure. We don't even know if this is going into all newer lenses or not.

Is there a reason that the existing data pin would not be sufficient to communicate the needed aperture settings? I really think a firmware change would be sufficient if they can use the data pin for this.

idk what you are saying

[ogl]

It works but only in manual focus mode if the body doesn't manage the in-lens motor.

A non-functional aperture is worse than a non-functional autofocus, of course.

All bodies from K100D super support SDM.
Who cares about first 6 MP cameras from Pentax?

K-3 or K-50 or K-5IIs are not old machines