[Simon K]

Let's say I had a K-50, in fact I have bought one for cheap recently, and the aperture block failure would happen one day, would the aperture of a PLM lens still work properly though?

[Waffles]

Yes it will.

[tabz]

Electronic aperture control is related to KAF4 system. This is supported with K-3 (latest firmware) or newer bodies only. K50 too.

[Simon K]

That's nice, I'm thinking of buying a 55-300 PLM anyway.

[Not a Number]

PLM refers to the type of motor used for autofocus. There is a mechanism limitation on PLM systems so it is possible that larger lenses would not use PLM but still have a KAF4 mount. So in order to have the in-lens aperture control the important thing to look for is the KAF4 mount, not just PLM.

[Simon K]

PLM refers to the type of motor used for autofocus. There is a mechanism limitation on PLM systems so it is possible that larger lenses would not use PLM but still have a KAF4 mount. So in order to have the in-lens aperture control the important thing to look for is the KAF4 mount, not just PLM.

Thanks for mentioning, I wasn't aware there might be KAF4 lenses other than those with PLM motor.

[mikesbike]

Would be interesting to see a list of KAF-4 lenses, these being usable on solenoid-disabled bodies.

[Rondec]

I think the KAF-4 lenses are:

DA *16-50 PLM
DA 55-300 PLM
DFA *50
DFA *85
DFA 70-210 f4

I don't think there are any others.

[StigVidar]

Let's say I had a K-50, in fact I have bought one for cheap recently, and the aperture block failure would happen one day, would the aperture of a PLM lens still work properly though?

On my camera the failed solenoid also initiated mirror flap problems. So the camera was not usable with any lens.

(There has not been a single mirror flap problem after the solenoid was replaced)

[normhead]

On my camera the failed solenoid also initiated mirror flap problems. So the camera was not usable with any lens.

(There has not been a single mirror flap problem after the solenoid was replaced)

My mirror flap problem disappeared without me doing anything. It just stopped happening a short time after I bought my camera.

[swanlefitte]

When my ks-2 developed the aperture problem I waited almost a year to fix it because I was using the 55-300 PLM mostly anyway.

[Ausable]

I think the KAF-4 lenses are:

DA *16-50 PLM
DA 55-300 PLM
DFA *50
DFA *85
DFA 70-210 f4

I don't think there are any others.

The new DFA 21 also has a KAF4 mount

[reh321]

On my camera the failed solenoid also initiated mirror flap problems. So the camera was not usable with any lens.

(There has not been a single mirror flap problem after the solenoid was replaced)

My K-30 developed solenoid problems, but I still use it {with old film lenses, that allow me to set the aperture at the lens, like ‘the old days’}; it has not developed mirror flap issues, at least so far it hasn’t. I have occasionally used the 55-300mm PLM lens with it, with the aperture being fully open instead of fully closed {as a ‘normal’ lens would be}, because Pentax hasn’t issued new firmware for the K-30, and I have decided not to use the ‘hacked’ variant.

[Simon K]

Fingers crossed, but if it happens anyways I have a white Japan solenoid at hand. I wonder though if any of the weather sealings would be compromised after opening the body.

[swanlefitte]

I have occasionally used the 55-300mm PLM lens with it, with the aperture being fully open instead of fully closed {as a ‘normal’ lens would be},

You really don't need it closed down. If it gives you auto focus and reads the correct zoom length for stabilization, there is nothing to gain from the hack. I have taken 1000's of photos with the lens and maybe 15 closed down doing "macro".