Pentax Pentax PLM Lens Compatibility ?

[phigmov]

Was watching this video (which is otherwise unremarkable) and the presenter mentioned the PLM lenses use the newer K mount variation which leaves older cameras without aperture control (tbf the K-5 is older than I thought!)

Appreciate the K-5 is getting on in years but electronic aperture control is such a fundamental part of DSLR's you kind of wonder why they left the ability out. I guess Nikon did something similar with the AF screw-drive (& G thing) but at least that was a moving part whereas I would have thought this is just an existing electrical connection. Is the PLM lens architecture so different?

 

[gordo]

Was watching this video (which is otherwise unremarkable) and the presenter mentioned the PLM lenses use the newer K mount variation which leaves older cameras without aperture control (tbf the K-5 is older than I thought!)

Appreciate the K-5 is getting on in years but electronic aperture control is such a fundamental part of DSLR's you kind of wonder why they left the ability out. I guess Nikon did something similar with the AF screw-drive (& G thing) but at least that was a moving part whereas I would have thought this is just an existing electrical connection. Is the PLM lens architecture so different?

IIRC the earlier bodies and lenses with no aperture rings used a different type of aperture control, the newer PLM models use electromagnetics. I'm thinking the new mode of control can't be upgraded by firmware in the earlier cameras.

edit - kind of like the Nikon G series vs newer E series AF-S lenses, the E lenses use electromagnetics and aren't compatible with the older DSLRs like the D70 where the G lenses work fine.

 

[phigmov]

Thanks for that info. I guess I assumed there might be some abstraction in there so the camera would say "give me f2.8" and the lens would take that instruction and act on it in a way that didn't need a FW update. I don't tend to get the latest models so I doubt I'll stumble across many of the PLM lenses (& I think my K-3 will work with a FW update) but it is something I'll bear in mind if I do come across them.

 

[gordo]

Thanks for that info. I guess I assumed there might be some abstraction in there so the camera would say "give me f2.8" and the lens would take that instruction and act on it in a way that didn't need a FW update. I don't tend to get the latest models so I doubt I'll stumble across many of the PLM lenses (& I think my K-3 will work with a FW update) but it is something I'll bear in mind if I do come across them.

I'm not 100% sure, but that's what I recalled. I know with Nikon my old D70 (and the other 2-digits IIRC) wouldn't work with the E glass, but the 3-digit from D300 up and the 4-digit from D3100 up would. Can't remember the 1-digit models. And going off memory, I might be off on some details.

Anywhos, the old 16mp sensor in the K bodies still make some nice images.