[Cerebum]

Hi
Just a quick question. Is there an easy way to recognise the new Pentax lenses that are not compatible with older DSLRs like my K30? I believe it is possible to load modified K50 firmware onto the K30 but there are so many lovely compatible Pentax DA lenses out there, even my LBA shouldn’t find me struggling. I just wanted to make sure I don’t inadvertently end up with something I can’t use.

Thanks in advance

Peter

[aslyfox]

Hi
Just a quick question. Is there an easy way to recognise the new Pentax lenses that are not compatible with older DSLRs like my K30? I believe it is possible to load modified K50 firmware onto the K30 but there are so many lovely compatible Pentax DA lenses out there, even my LBA shouldn’t find me struggling. I just wanted to make sure I don’t inadvertently end up with something I can’t use.

Thanks in advance

Peter

these charts might help

The Pentax Camera Lens Compatibility Chart

the K 30 is on the 4th line from the top

Pentax K-Mount Lenses Explained: The differences between various Pentax lens series

I would also go up to " Lenses " above and check out the user reviews and in depth reviews available for the lenses listed

[mikesbike]

The only one so far that has come along that would not work with your K-30 that I know of is the newer DA 55-300mm f/4.5-6.3 because it uses the new PLM AF motor.

[Cerebum]

The only one so far that has come along that would not work with your K-30 that I know of is the newer DA 55-300mm f/4.5-6.3 because it uses the new PLM AF motor.

That was the lens that made me wonder if there were others, or other things affecting compatibility. I think the PLM is the red flag to watch out for. Thanks

[Fogel70]

What you need to look out for is lenses with KAF4 lens mount.
It is not the PLM motor that is the problem. It is that KAF4 mount has an eletronically controlled aperture, and is missing the mechanical aperture lever your K30 need to control aperture.

At the moment there is only the above mensioned lens with KAF4 mount, and it is the only lens using PLM motor too. But the PLM motor can be used on older version of the mount, and there may come KAF4 lenses without PLM motor.

The lens database has information of the mount type on all lenses. As long as the lenses are KAF3 and earlier they should be fully compatible with your K30.
Pentax Lenses - Pentax Lens Reviews & Lens Database

[Adam]

these charts might help

The Pentax Camera Lens Compatibility Chart

the K 30 is on the 4th line from the top

Pentax K-Mount Lenses Explained: The differences between various Pentax lens series

I would also go up to " Lenses " above and check out the user reviews and in depth reviews available for the lenses listed

The only one so far that has come along that would not work with your K-30 that I know of is the newer DA 55-300mm f/4.5-6.3 because it uses the new PLM AF motor.

It's actually not the PLM but the KAF4 mount that causes the incompatibility. On the K-30, the focusing would work but the lens will always shoot wide-open since the camera doesn't know how to talk to the lens to set the aperture.

So, any future KAF3, KAF2, or KAF (screwdrive) lens will work with the K-30, while KAF4 will not.

[aslyfox]

It's actually not the PLM but the KAF4 mount that causes the incompatibility. On the K-30, the focusing would work but the lens will always shoot wide-open since the camera doesn't know how to talk to the lens to set the aperture.

So, any future KAF3, KAF2, or KAF (screwdrive) lens will work with the K-30, while KAF4 will not.

this article has info on the development of the K mount and what works with what

The Evolution of the Pentax K-mount - Articles and Tips | PentaxForums.com

[Cerebum]

Excellent, thank you :0)

[angerdan]

It's actually not the PLM but the KAF4 mount that causes the incompatibility.
On the K-30, the focusing would work but the lens will always shoot wide-open since the camera doesn't know how to talk to the lens to set the aperture.

So, any future KAF3, KAF2, or KAF (screwdrive) lens will work with the K-30, while KAF4 will not.

So it's not the mount (K-5 to K-70 use KAF2 regarding the camera database), but the firmware of the camera.
Mounts are physically and electronically identical and the feature was delivered to some cameras through firmware update.
Seems like some cameras did get KAF4 lens upward compatibility, others don't.

[Adam]

So it's not the mount (K-5 to K-70 use KAF2 regarding the camera database), but the firmware of the camera.
Mounts are physically and electronically identical and the feature was delivered to some cameras through firmware update.
Seems like some cameras did get KAF4 lens upward compatibility, others don't.

Correct, the K-3 and newer got an update while older models are not supported.

There is a physical difference with KAF4- they removed the aperture lever entirely so that the aperture mechanism is actuated electronically rather than through a physical linkage.

[Cerebum]

So it's not the mount (K-5 to K-70 use KAF2 regarding the camera database), but the firmware of the camera.
Mounts are physically and electronically identical and the feature was delivered to some cameras through firmware update.
Seems like some cameras did get KAF4 lens upward compatibility, others don't.

One of the guys on here has modified K50 firmware to work on the K30. This gives you the missing compatibility. I won’t be doing it because I don’t like taking risks but it is an option :0)