[jpzk]

FWIW I often use a monopod attached to the lens foot with my 70-200, which is also a beast.

Yes, good idea (which I do use as well the same way).
I'll tell her that.

User Tjompen1968 has encountered similar issue with both the DFA zooms. See the post by Tjompen1968 Uneven sharpness in DFA 70-200mm - Page 3 - PentaxForums.com There is video also.

Thanks, will check this out.

---------- Post added 05-11-18 at 10:17 AM ----------

I use the OP/TECH USA Lens Loop that @Aslyfox mentioned, attached to the OP/TECH USA Utility Strap–Sling XL Quick Adjust (Utility Strap?-Sling & Utility Strap?-Sling XL Quick Adjust - Neoprene Quick Release Camera Shoulder Strap | OP/TECH USA). The Lens Loop goes around the base of my FA*400 f/5.6 to support the weight of the lens, rather than the weight of the lens hanging from the camera body's mount. The Lens Loop is connected to the Utility Strap-Sling XL Quick Adjust. The neoprene part of the strap goes over my left shoulder, and the camera-lens combo hangs by my right hip so I can raise it with my right hand. See the photos on the page with the Lens Loop. Lens Loops - System Connector | OP/TECH USA
I have found OP/TECH USA's products to be durable.

I just saw this loop thing.
Does it not cause stress exactly where you don't want it?
I mean, it is right there where the connection is ... ?

Here is my take on the problem.... K-1 with DFA*70-200 or DFA150-450 Bad connection - PentaxForums.com

The bayonett on the two lenses are of a new design, they have more play, compared to other Pentax lenses. It tends to mostly happen when +2-+8 degees C, march - april in the area of Sweden I live in...

My gear is on route to Japan for them to test since they can't seem to create the problem themselves.

In a few weeks maybe I hear some news to what the problem is and if they have found a fix.

[biz-engineer]

There is always a bit of play between the lens and body. I had this "F"two times. The first time was after mounting the lens in cold humid weather. The second time, I cleaned the mount with alcohol and it works reliably since then. Up to 1.5Kg lens, it's no big deal to carry the lens via holding the body. I would hold carry a 2Kg+ lens via the camera body, and even less doing so with a 500mm or 600mm f4 lens.

[jpzk]

Here is my take on the problem.... K-1 with DFA*70-200 or DFA150-450 Bad connection - PentaxForums.com

The bayonett on the two lenses are of a new design, they have more play, compared to other Pentax lenses. It tends to mostly happen when +2-+8 degees C, march - april in the area of Sweden I live in...

My gear is on route to Japan for them to test since they can't seem to create the problem themselves.

In a few weeks maybe I hear some news to what the problem is and if they have found a fix.

Looking forward to find out what they'll do !

[aslyfox]

I don't know

send a PM to pete-tarmigan

he says he has used it I haven't used one yet

I would also suggest giving Optech USA a call

they have been very good at answering questions I have had about their products

[Mike.P®]

Nothing to do with the problem as such but I usually use my 150-450mm on a K-3II. Today mounted it on the K-1. The air suction was MUCH louder on the K-1 when zooming the lens back and foward, on the K-3II I hadn't even noticed it but on the full frame body it's very noticeable.

[jpzk]

I don't know

send a PM to pete-tarmigan

he says he has used it I haven't used one yet

I would also suggest giving Optech USA a call
they have been very good at answering questions I have had about their products

Good idea ! I'll get around that next week ...

---------- Post added 05-11-18 at 02:43 PM ----------

Nothing to do with the problem as such but I usually use my 150-450mm on a K-3II. Today mounted it on the K-1. The air suction was MUCH louder on the K-1 when zooming the lens back and foward, on the K-3II I hadn't even noticed it but on the full frame body it's very noticeable.

Better/tighter sealing at the "connections" ?

[aslyfox]

Good idea ! I'll get around that next week ...

you said I had a ' good idea '

why are you trying to ruin a well earned reputation that took years to build?

if people think I have good ideas to offer

then I will have to try to live up to that

[pete-tarmigan]

Yes, good idea (which I do use as well the same way).
I'll tell her that.

Thanks, will check this out.
---------- Post added 05-11-18 at 10:17 AM ----------

I just saw this loop thing.
Does it not cause stress exactly where you don't want it?
I mean, it is right there where the connection is ... ?

The Lens Loop rests on the barrel of the lens right next to the tripod/collar, not the body, so most of the weight of the lens/body combo is on the lens barrel. This applies to my K-3 and K-1, but I don't know if it's different for Canon or Nikon bodies. The barrel is designed to handle the strain, as evident by the location of the tripod collar. A little the weight is also distributed to the front edge of the base plate of the camera body. The weight on the mount is now coming from the body, which is much lighter than the lens, and which the mount is designed to handle. In addition, some of the weight is taken off the lens barrel because the lens/camera combo is pointed lens-end downward at a 45° angle rather than horizontal.

Other people have solved this problem with a sling strap attached to the tripod socket of the lens's tripod foot. Black Rapid and other companies manufacture such a set-up. However, the gear has to be firmly screwed into the tripod socket so it doesn't come unscrewed, resulting in the lens/camera combo crashing to the floor. This also leaves the tripod socket unavailable. Also, Black Rapid's set-up costs about twice as much as OP/TECH USA's gear.

[jpzk]

you said I had a ' good idea '

why are you trying to ruin a well earned reputation that took years to build?

if people think I have good ideas to offer

then I will have to try to live up to that

I don't have a smilie for this ... so ...

---------- Post added 05-11-18 at 03:55 PM ----------

The Lens Loop rests on the barrel of the lens right next to the tripod/collar, not the body, so most of the weight of the lens/body combo is on the lens barrel. This applies to my K-3 and K-1, but I don't know if it's different for Canon or Nikon bodies. The barrel is designed to handle the strain, as evident by the location of the tripod collar. A little the weight is also distributed to the front edge of the base plate of the camera body. The weight on the mount is now coming from the body, which is much lighter than the lens, and which the mount is designed to handle. In addition, some of the weight is taken off the lens barrel because the lens/camera combo is pointed lens-end downward at a 45° angle rather than horizontal.

Other people have solved this problem with a sling strap attached to the tripod socket of the lens's tripod foot. Black Rapid and other companies manufacture such a set-up. However, the gear has to be firmly screwed into the tripod socket so it doesn't come unscrewed, resulting in the lens/camera combo crashing to the floor. This also leaves the tripod socket unavailable. Also, Black Rapid's set-up costs about twice as much as OP/TECH USA's gear.

Thanks for explanation.
I've taken another look and what is shown (your link to the loop thing) ... and it does make sense indeed.
Took me twice though ...

[pete-tarmigan]

I don't have a smilie for this ... so ...
---------- Post added 05-11-18 at 03:55 PM ----------

Thanks for explanation.
I've taken another look and what is shown (your link to the loop thing) ... and it does make sense indeed.
Took me twice though ...

It's been working well so far -- my lens weighs 1140 g (2 lbs, 8.2 oz.).

[csa]

The Lens Loop rests on the barrel of the lens right next to the tripod/collar, not the body, so most of the weight of the lens/body combo is on the lens barrel.

Be sure to check that the lens loop cannot rub against the lens release on the camera!

[pete-tarmigan]

Be sure to check that the lens loop cannot rub against the lens release on the camera!

Also, when mounting a lens equipped with an aperture ring onto the body, try not to grasp the Lens Loop while rotating the lens because, if the Loop is over the aperture ring, you may not feel the "A" button and you can engage that button and move the aperture ring from the "A" setting. Then the F---- will show up in the viewfinder, telling you that the body is receiving no aperture information from the lens.

So far, I haven't had a problem that @csa mentions on the K-3 or K-1 with my FA*400mm, i.e., the Lens Loop rubbing against the body's lens release button.

[csa]

That's good to hear; I might get the Lens Loop then, for my 300 F4.

[pete-tarmigan]

That's good to hear; I might get the Lens Loop then, for my 300 F4.

The DA* 300mm f/4 is about the same diameter, 0.6 inches shorter, and 2.5 ounces lighter than the FA* 400mm f/5.6, so it should work similarly with the Lens loop and sling strap. And the Lens Loop is made by those fine Montana people.