Loose casing on 45mm lens...???

greenspun.com : LUSENET : Pentax 67 SLR : One Thread

I have a late model 45mm lens in excellent shape except that it has a loose front metal casing. (I guess that's what you'd call it) It is the part of the lens that filters attach to and it goes back just under the focus ring. It doesn't hold the front or any other elements. It is just loose enough to be a bit annoying, and I think it would only cause problems if I were to use a polarizing filter, which I don't have for it yet. I would say that it wobbles back and forth at most 1/16 of an inch. I'm wondering if anyone has experienced this before, and if so, is there a quick fix or does it need to be sent to Pentax for service? Has some glue broken down or possibly a loose screw?

I'm not sure how old the lens is, which probably doesn't matter, but the serial number is 8599013. On that note, isn't there a secret to telling how old a Pentax lens is by it's serial number?

Thanks very much, Randy Darst

-- Randy Darst (darstdesign@cfu.net), November 19, 2000

Answers

There is a loose correlation between serial number and production date for the 6x7 lenses. There is a thread in this forum on that subject so you might want to check it out. My guess on the production date of your 45mm is 1994. SR

-- Steve Rasmussen (srasmuss@flash.net), November 21, 2000.

Hi Randy,

I experiance this once with a Pentax (35mm) lens and I'm almost sure it works the same with the 45/4. First you have to remove the shield ring (the one which says Pentax SMC ....) basically you need a special tool to get grip on this ring but with a needle you can get grip on one of the holes (for example the dot in 4.0)when the ring is moving you can screw it out with your fingers. Behind the shield ring you will find 3 small srews which are probably lose.

Never ever use much force and he careful not to scratch. Good Luck

Gert Jan

-- Gert Jan Bollen (Gert.Jan.Bollen@philips.com), November 21, 2000.


Hi Gert Jan,

As far as I can tell, I don't think this P67 45mm lens is built quite the same as the lens with which you experienced the problem. The "shield ring" doesn't seem to want to screw off, it is the part that is loose, so it just wobbles back and forth. I will send a separate e-mail to you with a couple attached photos of the lens with arrows pointing to the loose part of the lens... maybe this will help?

Thanks for your advise! Randy

Also, thanks Steve for the info on Pentax serial numbers...

-- Randy Darst (darstdesign@cfu.net), November 28, 2000.


On my 45mm (latest style) the inner ring just below the filter thread loosened and was wobbly. Since it does not have any spanner wrench slots I re-tightened it using the pressure of a pencil eraser. Worked fine.

-- Garrett Adams (gadams@jps.net), November 28, 2000.

This has no effect on the optical quality of your lens and even if you used a polarizer filter 1/16 of an inch wouldn't amount to much if any difference in polarization.

Stop trying to fix something that isn't broken and go out and take some pictures would be my advice. Screw around with it long enough and Murphy's law will kick in resulting in a nick on the front element or worse.

People will want to look at pictures not your lens.

Peace, Rolland

-- rolland elliott (rolland_elliott@yahoo.com), November 29, 2000.



Thanks for the advice, Rolland. I haven't take a single tool, be it a screw driver, pencil eraser, or a piece of well chewed bubble gum to the lens, and I probably won't! I just wondered if anyone out there had experienced the same problem, and knew of a quick fix.

I must say, your comments sound like something my father would say... thanks! Randy :)

-- Randy Darst (darstdesign@cfu.net), November 29, 2000.


Moderation questions? read the FAQ