[bladerunner6]

Now that the firmware upgrade is available, I would be curious to know what the AF performance is with both these lenses on older bodies. I have a K-50 and this could be useful info.

[The Squirrel Mafia]

It should lock AF as fast as the K-3/3II does, but the AF module in the K-3/3II is more advanced & accurate than the AF module in the K-50.

I've been wanting to get the HD 55-300 WR screw drive for a while now, but after getting that firmware updae, now I have my eyes set on the HD 55-300 WR PLM instead.

[Adam]

The AF speed should still be much faster. Not sure about tracking, but the PLM lens does lock focus super quickly, even from the minimum focus setting. It's over a second faster in that scenario.

[rrstuff]

It's over a second faster in that scenario.

Dang. I hope they will release more lenses with this motor. I could really use a DA 35 PLM.

[Adam]

Dang. I hope they will release more lenses with this motor. I could really use a DA 35 PLM.

Yup, that would be nice.

DC lenses aren't far behind in terms of raw AF speed, but the difference between the two 55-300mm's is like night and day because the old version had such a long throw.

Not sure if you've seen this, but it's an eye-opener:

You Tube

You Tube

[bladerunner6]

Yup, that would be nice.

DC lenses aren't far behind in terms of raw AF speed, but the difference between the two 55-300mm's is like night and day because the old version had such a long throw.

Not sure if you've seen this, but it's an eye-opener:
New vs. Old Pentax 55-300mm Autofocus Test - YouTube

WOW!

Thanks for posting.

[Kerebron]

WOW! - exactly.

I've been sitting on a fence about this choice (new vs. old 55-300), but now I have no doubts. I'm going for the new one. It's definitely worth that extra money you have to pay for it. Thank you, Adam.

[ZombieArmy]

Yup, that would be nice.

DC lenses aren't far behind in terms of raw AF speed, but the difference between the two 55-300mm's is like night and day because the old version had such a long throw.

Not sure if you've seen this, but it's an eye-opener:
New vs. Old Pentax 55-300mm Autofocus Test - YouTube

What is this voodoo magic??? Do i need to call a witch doctor????????????

Is there any article explaining exactly what Pentax's PLM is?

[Adam]

What is this voodoo magic??? Do i need to call a witch doctor????????????

Is there any article explaining exactly what Pentax's PLM is?

It's just a pretty quick AF motor. Nikon also has a 55-300mm with a pulse motor

And yes, the focusing speed is crazy! If Pentax picks up continuous/video AF performance in camera, there's huge potential with this lens.

[ZombieArmy]

It's just a pretty quick AF motor. Nikon also has a 55-300mm with a pulse motor

And yes, the focusing speed is crazy! If Pentax picks up continuous/video AF performance in camera, there's huge potential with this lens.

I think we need better video quality and mechanical stabilization in video first

[boriscleto]

What is this voodoo magic??? Do i need to call a witch doctor????????????

Is there any article explaining exactly what Pentax's PLM is?

Only from the Ricoh Japan page...

HD PENTAX-DA 55-300mmF4.5-6.3ED PLM WR RE / Telephoto Lenses / K-mount Lenses / Lenses / Products | RICOH IMAGING

High-speed AF operation
With the adoption of a rear-focus system, the focusing lens is 93.6 percent lighter* than the previous version. By driving this focusing lens using a pulse motor (PLM), which is directly linked to a lead screw, this zoom lens operates faster — approximately 8.3 times** at its wide-angle end and approximately 1.7 times** at its telephoto end —and quieter than the existing model.* When mounted on the new PENTAX K-70 digital SLR camera body, it assures smoother, faster AF operation with dimly lit subjects, thanks to an improved AF algorithm that exchanges AF data between the camera body and the lens with greater precision. Operability of its power-assisted focus system during manual-focus operation has also been improved. Since its distance ring is designed to accurately detect the angle of rotation and swiftly react to a change of angle, this zoom lens can shift its focusing lens smoothly in response to distance ring operation.

* When compared with the HD PENTAX-DA 55-300mm F4-5.8ED WR.
** When taking a still image in K-70's viewfinder shooting, with the camera’s AF mode set to AF-S and for subjects positioned at a distance between 1.5 meters to infinity.

[FantasticMrFox]

It's just a pretty quick AF motor.

It's not just the motor, they redesigned the entire focusing group and made it over 90% lighter. Which unfortunately suggests the PLM would not deliver the same blazingly fast results with heavier lens elements used in faster aperture lenses.

It's impressive nonetheless.

[totsmuyco]

Looking at that comparison I wish there would be a software update on the k-5II/s. Maybe, they'll have aperture lever and PLM drive on the next lenses. Now I feel like dumping my HD 55-300 WR.

[rrstuff]

Yup, that would be nice.

DC lenses aren't far behind in terms of raw AF speed, but the difference between the two 55-300mm's is like night and day because the old version had such a long throw.

Not sure if you've seen this, but it's an eye-opener:
New vs. Old Pentax 55-300mm Autofocus Test - YouTube

Dang.

[gaweidert]

Looking at that comparison I wish there would be a software update on the k-5II/s. Maybe, they'll have aperture lever and PLM drive on the next lenses. Now I feel like dumping my HD 55-300 WR.

I have one of the older 55-300 lenses. My biggest problem is focus locking. The lens seems to be constantly searching. I actually use it more in manual focus mode than autofocus mode. Just something I am more comfortable with based upon 4 decades of using manual focus lenses. I got mine new for something like $266 and I have no complaints about it because of what I paid for it. Optical quality is very good to excellent.

Now that I have a K1, I figure that I am through buying APS dedicated lenses. In fact I only own three lenses that are specific to that format. I still use my APS format cameras, but unless one of my APS lenses fails, I see no real need to get anymore of them.