Praktica LTL 3 - stuck lens diaphragm...

[Luddite Frank]

Last night I was rummaging around in my camera closet, and unearthed a Praktica LTL3, that I had picked-up a couple years ago.

Nice cosmetics, body seems to work ok (meter unknown, don't have a battery to try in it right now), but the diaphragm in the lens seems to be stuck wide-open.

Lens is a "Pentacon f:1.8/50 Auto" .

Nothing I do to the lens causes the slightest movement of the aperture blades: set the selector to M or A, play with the coupling pin, rotate the aperture setting ring, nothing.

The glass it pretty clear, no tool marks on any of the grub screws or spanner rings, no signs of corrosion, or even heavy use for that matter.

I am assuming that lube has migrated into aperture mechanism, and has "glued" the blades open ?

Is this a common problem with this lens?

Any easy fixes, or is this a complete CLA job for a pro ?

Thanks...

LF

 

[ThreeToedSlothLuke]

I have the same camera/lens combo although I haven't used them in years. So I just checked by pressing the 'depth of view' lever & the blades stop down.
So I would suggest yours is just gummed up. If you want to try & fix it yourself a replacement lens on evil-bay can be had for $36 to $269 (I was curious so I checked that too) but probably not worth sending off for a CLA.

Colin

 

[xayraa33]

If you are good with your hands and have good eyesight you could take the lens apart and get at the aperture blades and clean them in Ronsonol or better yet 99% Isopropyl alcohol and correctly re-assemble everything (the hard part).

https://www.youtube.com/watch?v=I-06BGrA6Bo

 

[tunalegs]

I would not bother taking the lens apart unless you have the experience and tools necessary. It's a common lens, and readily available for low cost.

 

[Guth]

I hope that you are able to resolve the problem with your lens.

My very first "serious" camera was a close cousin of your LTL 3 — a Hanimex Praktica LTL. I haven't thought about that camera in quite some time but I can still recall how thrilled I was to own it. Having control over the aperture, shutter speed and focus for the first time ever kind of blew my mind back then.

 

[Luddite Frank]

Thanks for the comments and suggestions...

I rummaged around some more in the camera closet, and found a Pentax SV with clip-on Meter, and borrowed the 55/1.8 Super Takumar lens, and the 625-A akaline cell, and swapped both onto the Praktica LTL 3.

Meter works, and Pentax lens seems to work as is should.

I will see about hunting-up a working example of the original lens, as I do not feel at all competent to try to service the gummy one.


Regards,

LF

 

[seany65]

I don't know if it's a common problem with that lens, but there is one in a shop a few miles away from me and the aperture sometimes sticks open even when set on manual and at f16, sometimes it's alright. I pressed the pin a few times myself and the aperture sometimes stays open even when the pin is pressed. gets stuck. There is also another pentacon lens (focal length forgotten) on ebay that has the pin stuck down, but I don't know if the blades are open or closed.