[jchabalk]

I have a Pentax "67" and several lenses that i purchased about 15 years ago from the original owner. I used the camera pretty regularly for a couple of years and for the last ~10 years it's been stored away. i'd take it out occasionally and put it through its paces but it hasn't seen much regular use. It's overall in excellent condition - looking mostly new still.


So i took it out last weekend with a fresh battery and put a few roles through it and it works perfectly well. Something i noticed though is that when mounting a lens to it there's a good deal of friction between the lens and the body - it doesn't feel like anything's out of alignment, more like there's some adhesive almost causing friction. I get the same feeling when mounting or removing any of my lenses.


Maybe related to this i notice that the light seal material between the prism and the body is degrading and turns into an almost rubbery material. As far as i know this camera's never been serviced and i'm sure it could use a service but there's nothing clearly wrong with it other than this peculiarity.

I might try to gently clean the lens mount with a q-tip and some 99% alcohol to see if that validates my theory and addresses the issue.


I'm wondering if anyone else has had this happen and at the same time does your lens mount to the camera smoothly or is there a bit of friction when you do it.

Here's a picture of most of my 67 kit (attached)

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[tuco]

Yes both my Pentax 6x7 and 67 have friction mounting them. How much is hard to quantify with words except to say more than any of my small format cameras (67 has way more friction area) but not enough to cause me alarm that something is wrong. I've owned my Pentax 6x7 since new. But a cleaning is good idea. I'm sure mine could use it too.

[jchabalk]

this thing's weird, it takes what i would say is "too much" effort to attach/remove lenses. I just ran a q-tip with 99% isopropyl around the lens mounting flange on the camera and a couple of lenses and i'm definitely getting some black material on the q-tip. it looks like there's some light seal material between the body and lens mount, but it's pretty far back in there and i don't want to go digging to aggressively.

I'm going to clean the rest of the lenses and do the body one more time and then use it some more and see if it gets any better.

[Fogel70]

I have never seen a 67, but I believe most lens mounts have a couple of springs on the inside of the bayonet to minimize play between lens and camera and for better control of the friction when mounting the lens. But if dust or other particles get stuck between the lens bayonet surface and the spring, the spring can not be compressed fully and the friction increases.

But it may be difficult to clean this without proper tools

[ProfessorBuzz]

On the camera:
Besides cleaning the front surface of the camera mount, you kind of have to carefully get around the back part of where the lens bayonet goes into the mounting flange.

Also, the bayonet on the lens is one place where dirt hides - between the back side of the lens and bayonet - a tricky place to clean. I use narrow cotton swabs or Kimwipes to "floss" in between there.

So if the mounting end of the lens is like this:
----]----------[---
where the [ represents the flange, get in the corners and narrow parts of the bayonet "blades" [


I've bought a few used lenses over the years, and it's always grimy in there.

[jchabalk]

Do you guys know if there's a light seal between the lens mounting flange and the body? It kind of looks like it (see attached) but i didn't want to dig in there too far as i don't think the lens bayonet actually reaches in there that far. That stuff appears all the way around the flange


I'm going to try to get a little deeper around the springs and on the lens mounts as well.

[jchabalk]

I got in there pretty good with some modified q-tips and 99% isopropyl this afternoon. I'm pretty sure this is the problem i'm having. I got a lot of black gook out from around the lens flange on the body, very little from the mount on any of the lenses.


Mounting and removing lenses now isn't as smooth as other camera systems but it's much more reasonable than it was. I'll probably end up sending this body in for servicing at some point but this seems to be a pretty good improvement and there's really nothing else to complain about with this camera.

[desertscape]

Be aware that there are some machining differences between copies of lenses and bodies. The dimensions of each copy are not exactly the same due to manufacturing variability. Most lenses fit the body fairly well but I have had a couple of lenses that were tight.