[HArendsen]

I recieved my Sigma 18-250 mm F3.5-6.3 DC HSM OS yesterday! Very nice one.

[photogem]

About your DA55-300PLM:

This. The lens will work, but wide open all the time.

Not sure if that will bring issues when shooting in auto & the camera thinks that it's using a certain aperture & sets the shutter speed & exposure for that & then images come out too bright. I figure that if one is in Av, Tav, P, M, or B with the lens open, one shouldn't have issues. I could be wrong, though.

I either haven't found the AW versions of the Lenses I have, or decided against them due to price. I'm more for the AW versions for the protection, but I think I'm also limited on the K-5 being WR anyway instead of AW.

There are 2 older versions of a DA55-300:
The non WR SMC-Pentax-DA-55-300mm-F4-5.8
and the WR HD-Pentax-Da-55-300mm-f4-5.8-ED-WR
Those two will/would work without any issues, but not so the late PLM-Version which you have!

You wrote previously:

55-300mm HD Pentax DA 4.5-6.3 ED PLM WR RE - my latest acquisition I have been very pleased with

.... However, everything said above, I got my 55-300 Lens and I was nervous with the Reviews stating that because of the APK4 Mount required that I was going to have errors and such interfering with my new Lens. Of course, I upgraded the to the newest Firmware, and I have zero issues, so far.

Which cannot be! You only perceive it like this and it is very important to make this clear because otherwise others might think they could use the
this DA55-300PLM lens on their K5-Series!
As it was stated before, you can use it but ONLY WIDE-OPEN, which you might not even notice if you shoot in AUTO mode.

But if you use Av or Tav or P-modes then you will notice that the aperture cannot be changed.
Depending on focal lenth the aperture is of course different wide open: f4.5 at 55mm up to f6.3 at 300mm

So you have issues but you never noticed!

[AdkMtnGuy]

About your DA55-300PLM:



There are 2 older versions of a DA55-300:
The non WR SMC-Pentax-DA-55-300mm-F4-5.8
and the WR HD-Pentax-Da-55-300mm-f4-5.8-ED-WR
Those two will/would work without any issues, but not so the late PLM-Version which you have!

You wrote previously:

Which cannot be! You only perceive it like this and it is very important to make this clear because otherwise others might think they could use the
this DA55-300PLM lens on their K5-Series!
As it was stated before, you can use it but ONLY WIDE-OPEN, which you might not even notice if you shoot in AUTO mode.

But if you use Av or Tav or P-modes then you will notice that the aperture cannot be changed.
Depending on focal lenth the aperture is of course different wide open: f4.5 at 55mm up to f6.3 at 300mm

So you have issues but you never noticed!

I shoot P and Aperture all the time, yet I know I cannot adjust the Aperature, and therefore so far, it hasn't made any difference even with the Candid Photography I've done. I'll have to post some pictures when I get the chance.

[photogem]

I shoot P and Aperture all the time, yet I know I cannot adjust the Aperature, and therefore so far, it hasn't made any difference even with the Candid Photography I've done. I'll have to post some pictures when I get the chance.

Of course it made no difference because it always is (just) wide open.
For that it is nice, of course and always better than the earlier DA55-300's wide open.
But for example if you use LiveView the K5 measures in a particular way as does the K3, KP and K1.
This isn't possible either.