[carlb]

I have a new to me K-3 body and my DA 20-40 zoom mounts easily and smoothly but my DA70 is quite a bit harder to put on. I've cleaned the lens and camera mounts well with a cloth and it's a bit better, but still noticeably harder to get on (there's no risk of damage but it requires more effort than it should). What is odd is that the 70 goes on to my other bodies easily and other lenses attach smoothly to the K-3.

Is there anything I can try to make mounting this lens on my K-3 easier and smoother or are some lenses just harder to get on a camera?

[BigMackCam]

Do you hold the lens release button in while mounting lenses? I've found this can make a difference with some, especially if the lens release mechanism on the camera is a little bit on the "firm" side, or the lens locking pin is sharp or unduly wobbly. It also reduces that scratching you see on lens mounts - though some of that is unavoidable due to the electrical contacts on the body...

[hcc]

I have a K-3 as well. I have one lens which is hard to mount: my DA40mm xs. Most other lenses are easy to relatively easy to mount. To the best of my knowledge, you need to be patient because there is no 'miracle' formula/solution.
My 5 cents ...

[Fogel70]

I have never encountered a Pentax lens that is hard to mount, but several lenses from other brands

What I noticed though is that these lenses are extra hard to mount on my K3 II.
It is not as noticable on my KP and K7, or other older bodies.

So it is seems like a combination of a mount that is a little tighter on K3-series and with same problem on your DA70.
It is probably because of the leaf-springs on the inside of the mount on the camera that create a little more tension.

I do not think it is much to do, other than to use the lens and hope that it loosen up after some use.

[Terry C]

Just manufacturing tolerances.

[eles]

I have a new to me K-3 body and my DA 20-40 zoom mounts easily and smoothly but my DA70 is quite a bit harder to put on. I've cleaned the lens and camera mounts well with a cloth and it's a bit better, but still noticeably harder to get on (there's no risk of damage but it requires more effort than it should). What is odd is that the 70 goes on to my other bodies easily and other lenses attach smoothly to the K-3.

Is there anything I can try to make mounting this lens on my K-3 easier and smoother or are some lenses just harder to get on a camera?

@carlb - thanks! for asking this question. Not too long ago I purchased a used Pentax 77mm Ltd, and it is more difficult to mount on my K-1 than my other lenses. I was going to make a post asking about this, but never got around to it. Practise, holding down the lens release button, and cleaning the lens and camera mounts seems to have helped a bit, but it still doesn't mount as smoothly as I'd like.